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    Endophytic bacterial communities are associated with leaf mimicry in the vine Boquila trifoliolata

    1.Wiens, D. Mimicry in plants. Evol. Biol. 11, 365–403 (1978).
    Google Scholar 
    2.Pasteur, G. A classificatory review of mimicry systems. Annu. Rev. Ecol. Syst. 13, 169–199 (1982).
    Google Scholar 
    3.Barrett, S. C. H. Mimicry in plants. Sci. Am. 257, 76–85 (1987).
    Google Scholar 
    4.Barlow, B. A. & Wiens, D. Host-parasite resemblance in Australian mistletoes: The case for cryptic mimicry. Evolution 31, 69–84 (1977).PubMed 

    Google Scholar 
    5.Ehleringer, J. R. et al. Mistletoes: A hypothesis concerning morphological and chemical avoidance of herbivory. Oecologia 70, 234–237 (1986).ADS 
    CAS 
    PubMed 

    Google Scholar 
    6.Canyon, D. V. & Hill, C. J. Mistletoe host-resemblance: A study of herbivory, nitrogen and moisture in two Australian mistletoes and their host trees. Aust. J. Ecol. 22, 395–403 (1997).
    Google Scholar 
    7.Blick, R. A. J., Burns, K. C. & Moles, A. T. Predicting network topology of mistletoe–host interactions: Do mistletoes really mimic their hosts?. Oikos 121, 761–771 (2012).
    Google Scholar 
    8.Gianoli, E. & Carrasco-Urra, F. Leaf mimicry in a climbing plant protects against herbivory. Curr. Biol. 24, 984–987 (2014).CAS 
    PubMed 

    Google Scholar 
    9.Gianoli, E., Saldaña, A., Jiménez-Castillo, M. & Valladares, F. Distribution and abundance of vines along the light gradient in a southern temperate rainforest. J. Veg. Sci. 21, 66–73 (2010).
    Google Scholar 
    10.Gianoli, E. Eyes in the chameleon vine?. Trends Plant Sci. 22, 4–5 (2017).CAS 
    PubMed 

    Google Scholar 
    11.Gianoli, E. & Molina-Montenegro, M. A. Leaf damage induces twining in a climbing plant. New Phytol. 167, 385–390 (2005).PubMed 

    Google Scholar 
    12.González-Teuber, M. & Gianoli, E. Damage and shade enhance climbing and promote associational resistance in a climbing plant. J. Ecol. 96, 122–126 (2008).
    Google Scholar 
    13.Calder, D. M. Mistletoes in focus: An introduction. In The Biology of Mistletoes (eds Calder, D. M. & Bernhardt, P.) 1–18 (Academic Press, 1983).
    Google Scholar 
    14.Cook, M. E., Leigh, A. & Watson, D. M. Hiding in plain sight: Experimental evidence for birds as selective agents for host mimicry in mistletoes. Botany 98, 525–531 (2020).
    Google Scholar 
    15.Atsatt, P. R. Mistletoe leaf shape: A host morphogen hypothesis. In The Biology of Mistletoes (eds Calder, D. M. & Bernhardt, P.) 259–275 (Academic Press, 1983).
    Google Scholar 
    16.Hall, P. J., Badenoch-Jones, J., Parker, C. W., Letham, D. S. & Barlow, B. A. Identification and quantification of cytokinins in the xylem sap of mistletoes and their hosts in relation to leaf mimicry. Aust. J. Plant Physiol. 14, 429–438 (1987).CAS 

    Google Scholar 
    17.Watson, D. M. Mistletoes of Southern Australia (CSIRO, 2019).
    Google Scholar 
    18.Holopainen, J. K. & Blande, J. D. Molecular plant volatile communication. In Sensing in Nature (ed. López-Larrea, C.) 17–31 (Springer Science, 2012).
    Google Scholar 
    19.Baldwin, I. T., Kessler, A. & Halitschke, R. Volatile signaling in plant–plant–herbivore interactions: What is real?. Curr. Opin. Plant Biol. 5, 351–354 (2002).CAS 
    PubMed 

    Google Scholar 
    20.Heil, M. & Karban, R. Explaining evolution of plant communication by airborne signals. Trends Ecol. Evol. 25, 137–144 (2010).PubMed 

    Google Scholar 
    21.Karban, R., Yang, L. H. & Edwards, K. F. Volatile communication between plants that affects herbivory: A meta-analysis. Ecol. Lett. 17, 44–52 (2014).PubMed 

    Google Scholar 
    22.Coyne, J. A. Fantastic and plastic mimicry in a tropical vine. Why Evolution is True Blog. http://whyevolutionistrue.com/2014/04/26/fantastic-and-plastic-mimicry-in-a-tropical-vine (2014).23.Pannell, J. R. Leaf mimicry: Chameleon-like leaves in a Patagonian vine. Curr. Biol. 24, R357–R359 (2014).CAS 
    PubMed 

    Google Scholar 
    24.Baluška, F. & Mancuso, S. Vision in plants via plant-specific ocelli?. Trends Plant Sci. 21, 727–730 (2016).PubMed 

    Google Scholar 
    25.Richardson, A. O. & Palmer, J. D. Horizontal gene transfer in plants. J. Exp. Bot. 58, 1–9 (2007).CAS 
    PubMed 

    Google Scholar 
    26.Bock, R. The give-and-take of DNA: Horizontal gene transfer in plants. Trends Plant Sci. 15, 11–22 (2010).CAS 
    PubMed 

    Google Scholar 
    27.Yoshida, S., Maruyama, S., Nozaki, H. & Shirasu, K. Horizontal gene transfer by the parasitic plant Striga hermonthica. Science 328, 1128 (2010).ADS 
    CAS 
    PubMed 

    Google Scholar 
    28.Christin, P. A. et al. Adaptive evolution of C4 photosynthesis through recurrent lateral gene transfer. Curr. Biol. 22, 445–449 (2012).CAS 
    PubMed 

    Google Scholar 
    29.Gao, C. et al. Horizontal gene transfer in plants. Funct. Integr. Genomics 14, 23–29 (2014).CAS 
    PubMed 

    Google Scholar 
    30.Diao, X., Freeling, M. & Lisch, D. Horizontal transfer of a plant transposon. PLoS Biol. 4, e5 (2006).PubMed 

    Google Scholar 
    31.El Baidouri, M. et al. Widespread and frequent horizontal transfers of transposable elements in plants. Genome Res. 24, 831–838 (2014).PubMed 
    PubMed Central 

    Google Scholar 
    32.Prentice, H. C., Li, Y., Lönn, M., Tunlid, A. & Ghatnekar, L. A horizontally transferred nuclear gene is associated with microhabitat variation in a natural plant population. Proc. R. Soc. B Biol. Sci. 282, 20152453 (2015).
    Google Scholar 
    33.Yu, A. et al. Dynamics and biological relevance of DNA demethylation in Arabidopsis antibacterial defense. Proc. Natl. Acad. Sci. 110, 2389–2394 (2013).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    34.Takahashi, K. Influence of bacteria on epigenetic gene control. Cell. Mol. Life Sci. 71, 1045–1054 (2014).CAS 
    PubMed 

    Google Scholar 
    35.Ramos-Cruz, D., Troyee, A. N. & Becker, C. Epigenetics in plant organismic interactions. Curr. Opin. Plant Biol. 61, 102060 (2021).CAS 
    PubMed 

    Google Scholar 
    36.Lodewyckx, C. et al. Endophytic bacteria and their potential applications. Crit. Rev. Plant Sci. 21, 583–606 (2002).
    Google Scholar 
    37.Ryan, R. P., Germaine, K., Franks, A., Ryan, D. J. & Dowling, D. N. Bacterial endophytes: Recent developments and applications. FEMS Microbiol. Lett. 278, 1–9 (2008).CAS 
    PubMed 

    Google Scholar 
    38.Barrett, S. C. H. Crop mimicry in weeds. Econ. Bot. 37, 255–282 (1983).
    Google Scholar 
    39.McElroy, J. S. Vavilovian mimicry: Nikolai Vavilov and his little-known impact on weed science. Weed Sci. 62, 207–216 (2014).CAS 

    Google Scholar 
    40.Ye, C.-Y. et al. Genomic evidence of human selection on Vavilovian mimicry. Nat. Ecol. Evol. 3, 1474–1482 (2019).PubMed 

    Google Scholar 
    41.Ruiz, E. Lardizabalaceae. In Flora de Chile Vol. 2 (eds Marticorena, C. & Rodríguez, R.) 24–27 (Universidad de Concepción, 2003).
    Google Scholar 
    42.Muñoz-Schick, M. Flora del Parque Nacional Puyehue (Editorial Universitaria, 1980).
    Google Scholar 
    43.Dorsch K. Hydrogeologische Untersuchungen der Geothermalfelder von Puyehue und Cordón Caulle, Chile. PhD thesis (Ludwig-Maximilians-Universität, 2003).44.Valladares, F., Saldaña, A. & Gianoli, E. Costs versus risks: Architectural changes with changing light quantity and quality in saplings of temperate rainforest trees of different shade tolerance. Austral Ecol. 37, 35–43 (2012).
    Google Scholar 
    45.Salgado-Luarte, C. & Gianoli, E. Shade-tolerance and herbivory are associated with RGR of tree species via different functional traits. Plant Biol. 19, 413–419 (2017).CAS 
    PubMed 

    Google Scholar 
    46.Salgado-Luarte, C. & Gianoli, E. Herbivory on temperate rainforest seedlings in sun and shade: Resistance, tolerance and habitat distribution. PLoS One 5, e11460 (2010).ADS 
    PubMed 
    PubMed Central 

    Google Scholar 
    47.Salgado-Luarte, C. & Gianoli, E. Herbivores modify selection on plant functional traits in a temperate rainforest understory. Am. Nat. 180, E42–E53 (2012).PubMed 

    Google Scholar 
    48.Sun, B. Y., Stuessy, T. F., Humaña, A. M., Riveros, G. M. & Crawford, D. J. Evolution of Rhaphithamnus venustus (Verbenaceae), a gynodioecious hummingbird-pollinated endemic of the Juan Fernandez Islands, Chile. Pac. Sci. 50, 55–65 (1996).
    Google Scholar 
    49.Saldaña, A. & Lusk, C. H. Influencia de las especies del dosel en la disponibilidad de recursos y regeneración avanzada en un bosque templado lluvioso del sur de Chile. Rev. Chil. Hist. Nat. 76, 639–650 (2003).
    Google Scholar 
    50.Gut, B. Árboles-Trees Patagonia. Árboles nativos e introducidos en Patagonia (Vázquez Mazzini, 2017).
    Google Scholar 
    51.Sahu, S. K., Thangaraj, M. & Kathiresan, K. DNA extraction protocol for plants with high levels of secondary metabolites and polysaccharides without using liquid nitrogen and phenol. ISRN Mol. Biol. 2012, 205049 (2012).PubMed 
    PubMed Central 

    Google Scholar 
    52.Lundberg, D. S., Yourstone, S., Mieczkowski, P., Jones, C. D. & Dangl, J. L. Practical innovations for high-throughput amplicon sequencing. Nat. Methods 10, 999–1002 (2013).CAS 
    PubMed 

    Google Scholar 
    53.Schloss, P. D. et al. Introducing mothur: Open-source, platform-independent, community-supported software for describing and comparing microbial communities. Appl. Environ. Microbiol. 75, 7537–7541 (2009).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    54.Quast, C. et al. The SILVA ribosomal RNA gene database project: Improved data processing and web-based tools. Nucleic Acids Res. 41, D590–D596 (2012).PubMed 
    PubMed Central 

    Google Scholar 
    55.Wang, Q., Garrity, G. M., Tiedje, J. M. & Cole, J. R. Naïve bayesian classifier for rapid assignment of rRNA sequences into the new bacterial taxonomy. Appl. Environ. Microbiol. 73, 5261–5267 (2007).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    56.Borcard, D., Gillet, F. & Legendre, P. Numerical Ecology with R (Springer, 2011).MATH 

    Google Scholar  More

  • in

    Integrate geographic scales in equity, diversity and inclusion

    1.McGill, B. M. et al. Ecol. Evol. 11, 3636–3645 (2021).Article 

    Google Scholar 
    2.Röβler, D. C., Lötters, S. & Da Fonte, L. F. M. Nature 584, 525–525 (2020).
    Google Scholar 
    3.Nuñez, M. A. et al. J. Appl. Ecol. 56, 4–9 (2019).Article 

    Google Scholar 
    4.Nuñez, M. A., Chiuffo, M. C., Pauchard, A. & Zenni, R. D. Trends Ecol. Evol. 36, 766–769 (2021).Article 

    Google Scholar 
    5.Maas, B. et al. Conserv. Lett. 14, e12797 (2021).Article 

    Google Scholar 
    6.Khelifa, R., Mahdjoub, M., Baaloudj, A. & Chaib, S. Facets https://doi.org/10.1139/facets-2021-0073 (in press).7.Haelewaters, D., Hofmann, T. A. & Romero-Olivares, A. L. PLoS Comput. Biol. 17, e1009277 (2021).CAS 
    Article 

    Google Scholar  More

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    Successful microbial colonization of space in a more dispersed manner

    Simulating competition for space using the “BacGo” modelTo investigate how spatial positioning of populations affects the outcome of microbial competition, we simulated two populations competing for space with a limiting size by building an individual-based model (named “BacGo”). The model was implemented in discrete grid boxes of a 20 × 20 array. As shown in Fig. 1a, our simulations were based on three basic assumptions. First, the two competing populations possess the same inherent growth rate and equal initial cell numbers, thus the only differences between them are their manners of colonizing free space. Second, the newly born daughter cell is located around its mother cell but with a random direction of spatial positioning [34], resulted in a microcolony with different spatial patterning. Lastly, if the selected box has been occupied, the newborn cell will compete for the box against the original occupants of the box and possesses a probability of 50% to survive [37].We first explored the outcome of spatial competition, which started by randomly distributing two populations on the grids with the same initial cell numbers of 10 for each. Based on our basic assumptions and the predictions of competitive exclusion theory [38], we hypothesized that only one population could win the competition and finally occupy all grids. As shown in 20,000 independent simulations with random initial distributions, we discovered that at the end of each simulation, only one population survived (Video S1 and Video S2). The Chi-square test showed no significant difference (P = 0.211) between the simulated winning times (10,177 of 20,000 simulations) and the random winning times (10,051 of 20,000 simulations) of the focus population. This result conformed with our initial assumption that cells possess a probability of 50% to survive in competing with original occupants. When we replicated simulations initiated with the same cell distribution, we found that the winning probabilities for each population changed in line with the initial distributions (Fig. S1). However, the winning probabilities never reached 100% no matter how the initial distribution changes. Together, these results suggested that unknown random factors may affect the final outcome of the competition.Next, we analyzed the dynamics of microbial colonization during our simulations. As summarized in Fig. 1b, we divided the competition process into two stages, the “occupation stage” and the “exclusion stage” (see Methods). To statistically characterize the competitive outcome at t3, we defined the winning asymmetry index, WinR, and the abundance asymmetry index, AbunR (see Methods). As shown in Fig. S2a, we found a strong positive correlation (R2 = 0.740, P  More

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    Photoheterotrophy by aerobic anoxygenic bacteria modulates carbon fluxes in a freshwater lake

    SamplingWater was sampled from Cep lake in Czechia, at a regular sampling site of 10 m depth (48.944 °N, 14.877 °E). The lake originates from sand mining in the 1970–80s. It is a permanent meso-oligotrophic (chlorophyll-a concentrations ranged from 1.4–16.4 µg L−1) seepage reservoir filled with groundwater penetrating from the nearby river Lužnice. The lake area is about 1.16 km2, with the maximum depth about 11–12 m. These characteristics are representative for most of temperate and boreal lakes [16].Samples were collected every four weeks from April till October in 2018, and from April till November in 2019. Ten liters of water were collected from 0.5 m depth using a Ruttner Water Sampler (model 11.003KC Denmark AS). Temperature and oxygen profiles were taken with an EXO1 multi-parameter probe (YSI Inc., Yellow Springs, USA). Water was transported to the laboratory within 2 h from the collection in a closed container made from high-density polyethylene, rinsed three times with the sampled water and stored in a cooled box.NutrientsSamples were filtered through glass fiber filters with 0.4 µm nominal porosity (GF-5, Macherey-Nagel, Düren, Germany). Concentrations of soluble reactive phosphorus (SRP) were determined spectrophotometrically [17, 18]. Concentrations of nitrate and ammonium were measured according to Procházková [19] and Kopáčkek and Procházková [20]. Dissolved organic carbon (DOC) and dissolved nitrogen (DN) were measured with a TOC 5000 A analyzer (Shimadzu, Kyoto, Japan).PigmentsSeston from 1.43 to 3.65 L of water was collected onto GF-5 glass fiber filters (diameter 47 mm, Macherey-Nagel). The filters were dried of excess water by gently pressing in a paper towel, and flush frozen in liquid nitrogen. Pigments were extracted and analyzed by HPLC as described in Piwosz et al. [21].Net primary production (NPP) and community respiration (oxygen measurements)Oxygen concentration was measured with the Winkler method [22]. It was chosen because it allows O2 concentration to be measured directly in the water without the need to consider carbonic equilibrium, which is the case when changes in CO2 concentration is measured [23]. Samples were unfiltered to avoid the removal of particle-associated bacteria and also of free-living AAP bacteria, which tend to be larger than average freshwater bacteria [12]. Glass stoppered Winkler type oxygen bottles (115 mL nominal capacity, VTR glass, Prague, Czechia) were filled with the sampled water directly from the sampler via a rubber tube. Each bottle was first rinsed three times and then filled without the formation of air bubbles. Water was allowed to overflow the neck of the bottle for about 1 min, and the bottle was closed with a glass stopper to avoid air bubbles. The closed bottles were kept in the dark in a cooled box. On the shore, three bottles were selected as T0, and 1.2 mL of manganese (II) chloride solution (concentration 3 mol L−1) was addded, followed by the addition of 1.2 mL of a mixture containing 4 mol L−1 of sodium iodide solution and 8 mol L−1 of sodium hydroxide solution. These samples were processed in the laboratory within 3 h. The remaining bottles were incubated for 24 h at in situ temperature in the IR-box prepared from the MAKROLON IR polycarbonate sheet (4 mm thickness, Professional Plastics, Inc. Fullerton, CA, USA). These panels have a maximum transmittance of 90% in the infrared region 850–2000 nm, 50% at 780 nm, and 0% 10 °C according to our measurements (180 days, Equation 3 in Supplementary File S1). Subsequently, the differences in the Cep Lake’s carbon budget for the surface layer (down to 0.5 m depth) were calculated by multiplying the integrated values by the volume of this layer (Equation 4 and 5 in Supplementary File S1).HCO3
    − incorporationTriplicated water samples (32 mL) were incubated for 3.2–5.2 h in the IR light and the dark at in situ temperature, as described for respiration. Total activity added to each bottle was measured from 1 mL aliquot of the incubated sample that was transferred to a scintillation vial containing 20 μl of 5 mol L−1 NaOH (to prevent a loss of 14C-bicarbonate). Thirty mL of sample was filtered through 2.5 μm nitrate cellulose filters (Pragopor, Prague, Czechia, diameter 25 mm). Five mL of the filtered water was collected and subsequently filtered through a 0.17 μm nitrate cellulose filter. The resulting cell-free filtrate, which contained 14C-DOC was collected. The filtration was done at a low vacuum (0.02 MPa) to avoid cell breakage. The total CO2 assimilation rate was calculated as the sum of all these fractions.The filters were kept in an HCl-saturated atmosphere for 24 h at room temperature in a fume hood. They were placed in scintillation vials and dissolved in 1 mL of ethyl acetate (Penta, Prague, Czechia). Then, 5 mL of Ultima Golt LLT scintillation cocktail (PerkinElmer, Waltham, MA, USA) was added. Five mL of cell-free filtrates were acidified by adding 100 μL 5 mol L−1 HCl to volatilize non-incorporated H14CO3 and incubated 24 h at room temperature in a fume hood. Then, 10 mL of the scintillation cocktail was added. Finally, 5 mL of the scintillation cocktail was added to the total activity samples. Subsequently, the samples were gently mixed and left in the dark for 48 h. The radioactivity in the samples was measured using a Tri-Carb 2810 TR scintillation counter (PerkinElmer).To estimate carbon fluxes (μmol C L–1 h–1), a fraction of the added H14CO3 incorporated or released was corrected for the incubation time and multiplied by the concentration of total dissolved inorganic carbon (DIC). The DIC concentration was calculated based on temperature, pH, and alkalinity measurements (Inolab pH 720, WTW Xylem Inc. Rye Brook, NY, US) determined by Gran titration.Assimilation of organic monomersThe difference between microbial activity in the IR light and dark was also estimated based on assimilation rates of radiolabeled glucose, pyruvate, leucine and thymidine (American Radiolabeled Chemicals, St. Louis, MO, USA). Tritiated glucose (specific activity (SA): 2220 GBq mmol−1), leucine (SA: 4440 GBq mmol−1) and thymidine (SA: 2275.5 GBq mmol−1) were added to 5 mL samples to a final concentration of 5 nmol L−1. 14C-pyruvate (SA: 2.035 GBq mmol−1) was added to a final concentration of 10 nmol L−1. Trichloroacetic acid (TCA) was added to the killed controls to a final concentration of 1%. Samples were incubated for 1 h in the dark and IR light as described for respiration. The incubations were terminated as the killed controls and kept at 4 °C in the dark until processed within 65% except for the samples from 9th May and 29th Aug 2018 (10% each), 1st Aug 2018 (21%), 25th Nov 2018 (1%), and 14th Aug 2019 (22%), Supplementary Fig. S1A). Thus, we decided to concatenate the fastaq files and analyze both fractions together as the total community. This also facilitated statistical analysis, as the activity rates were measured for the whole community without fractionations.Reads quality was evaluated using FastQC v0.11.7 (Babraham Bioinformatics, Cambridge, UK). After primer sequences trimming using Cutadapt [29] (v1.16), the number of reads per sample ranged from 49,354 to 188,942. Subsequent analyses were done in the R/Bioconductor environment using the dada2 package (version 1.14.1) [30]. Forward and reverse reads were truncated to 225 bp and low quality sequences were filtered out with the filterAndTrim function (truncLen = c(225, 225), maxN = 0, maxEE = c(2, 2), truncQ = 2), which reduced the number of reads per sample to range from 30,190 to 143,552. After merging and chimera removal using the removeBimeraDenovo function, 4,893 amplicon sequence variants (ASV) were obtained. Rare ASVs (not seen >3 times in at least 20% of the samples) were removed, which reduced the number of ASVs to 658, and the number of reads to 14,613–69,046 per sample. Taxonomic assignment was done using SILVA 138.1 database [31, 32] released on August 27, 2020. ASVs identified as Chloroplast or Cyanobacteria were excluded from the analyses, giving the final number of 546 ASVs and from 10,819 to 54,799 reads per sample. The bacterial community composition graphs were done using phyloseq [33] and ggplot2 [34] packages.AAP community compositionThe composition of AAP community was analyzed by amplicon sequencing of pufM gene encoding the M subunit of bacterial type-2 reaction centers. This gene is routinely used for diversity studies of AAP bacteria [35].PufM gene amplicons (approx. 245 bp) were prepared using pufM_UniF (5′-GGN AAY YTN TWY TAY AAY CCN TTY CA-3′) and pufM_WAW (5′-AYN GCR AAC CAC CAN GCC CA-3′) primers [36]. PCR was performed in triplicate 20 μL reactions using Phusion™ High-Fidelity DNA Polymerase (Thermo Scientific, USA) with the following reaction conditions: 98 °C for 3 min, 27 cycles at 98 °C for 10 s, 58 °C for 30 s, 72 °C for 30 s, and a final extension at 72 °C for 5 min. The triplicate product reactions for each sample were pooled and gel purified using the kit Wizard SV Gel and PCR Clean-Up System (Promega, USA). The sequencing was performed on the Illumina MiSeq platform (2 × 150 bp) at Macrogen, South Korea.The fastq files were concatenated as described for bacteria communities. The Bray-Curtis similarity between two fractions for each sampling day was >70%, except for the samples from 1st Aug 2018 (47%) and 14th Aug 2019 (18%, Supplementary Fig. S1B).The samples were analyzed as described for bacterial communities. The number of reads per sample ranged from 192,360 to 239,418 after the cutadapt trimming. Forward and reverse reads were truncated to 130 bp, and the number of reads per sample after the quality filtering and denoising ranged from 189,432 to 235,311. Merging the forward and reverse reads with mergePairs function created 12,692 ASVs and reduced the number of reads to 183,136–221,281 per sample. The chimera removal lowered the number of ASVs to 1816, and the number of reads to 159,451–208,679. Rare ASVs (not seen >3 times in at least 20% of the samples) were removed, which resulted in the final 566 ASVs, and a number of reads ranging from 155,915 to 203,021 per sample. A manually curated taxonomic database was used for taxonomic assignment following the naïve Bayesian classifier method [37]. It contained 1580 unique pufM sequences, downloaded from the Fungene repository on May 16, 2019 (http://fungene.cme.msu.edu [38]), from metagenomes from the Římov Reservoir [39, 40] and from the Genome Taxonomy database accessed on September 16, 2020 [41].Statistical analysisLinear mixed-effects models were calculated in R (version 3.6.2) using lme function from the nlme package (version 3.1.143) on untransformed activity data and log10 transformed environmental variables [42]. Models’ parameters were estimated using maximum likelihood method and their significance was tested with ANOVA. Relationships between the activity measures, the environmental variables and the composition of AAP communities were investigated with distance-based linear models (DistLM) [43, 44] in Primer (version 7.0.13) with PERMANOVA + 1 add on (e-Primer, Plymouth, UK) [45]. The sequence reads were transformed with the varianceStabilizingTransformation function of the DESeq2 package [46] (version 1.14.1, blind = FALSE, fitType = “mean”).Data accessibilityThe sequences of 16S and pufM amplicons that support the findings of this study have been deposited in the EMBL database as the BioProject with the accession number PRJEB41596, together with most of the environmental metadata. The scripts and the remaining data supporting the results are included in the Supplementary Material. More

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    Spatial distribution of conspecific genotypes within chimeras of the branching coral Stylophora pistillata

    1.Rinkevich, B. & Weissman, I. L. Chimeras in colonial inverebrates: A synergistic symbiosis or somatic- and cell-germ parasitism? Symbiosis 4, 117–134 (1987).
    Google Scholar 
    2.Buss, L. W. Somatic cell parasitism and the evolution of somatic tissue compatibility. Proc. Natl. Acad. Sci. U.S.A. 79, 5337–5341. https://doi.org/10.1073/pnas.79.17.5337 (1982).ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    3.Foster, K. R., Fortunato, A., Strassmann, J. E. & Queller, D. C. The costs and benefits of being a chimera. Proc. R. Soc. Lond. B 269, 2357–2362. https://doi.org/10.1098/rspb.2002.2163 (2002).Article 

    Google Scholar 
    4.Money, N. P. Fungal get-together. Nature 405, 751. https://doi.org/10.1038/35015659 (2000).CAS 
    Article 
    PubMed 

    Google Scholar 
    5.Franks, T., Botta, R., Thomas, M. & Franks, J. Chimerism in grapevines: Implications for cultivar identity, ancestry and genetic improvement. Theor. Appl. Genet. 104, 192–199. https://doi.org/10.1007/s001220100683 (2002).CAS 
    Article 
    PubMed 

    Google Scholar 
    6.Casares, A. & Sylvain, F. F. Higher reproductive success for chimeras than solitary individuals in the kelp Lessonia spicata but no benefit for individual genotypes. Evol. Ecol. 30, 953–972. https://doi.org/10.1007/s10682-016-9849-0 (2016).Article 

    Google Scholar 
    7.Santelices, B., González, A. V., Beltrán, J. & Flores, V. Coalescing red algae exhibit noninvasive, reversible chimerism. J. Phycol. 53, 59–69. https://doi.org/10.1111/jpy.12476 (2017).CAS 
    Article 
    PubMed 

    Google Scholar 
    8.Gauthier, M. & Degnan, B. M. Partitioning of genetically distinct cell populations in chimeric juveniles of the sponge Amphimedon queenslandica. Dev. Comp. Immunol. 32, 1270–1280. https://doi.org/10.1016/j.dci.2008.04.002 (2008).CAS 
    Article 
    PubMed 

    Google Scholar 
    9.Fidler, A. E., Bacq-Labreuil, A., Rachmilovitz, E. & Rinkevich, B. Efficient dispersal and substrate acquisition traits in a marine invasive species via transient chimerism and colony mobility. PeerJ 2018, 1–23. https://doi.org/10.7717/peerj.5006 (2018).CAS 
    Article 

    Google Scholar 
    10.Rinkevich, B. & Weissman, I. Chimeras in colonial invertebrates: A synergistic symbiosis or somatic-and germ-cell parasitism. Symbiosis 4, 117–134 (1987).
    Google Scholar 
    11.Amar, K.-O., Chadwick, N. E. & Rinkevich, B. Coral kin aggregations exhibit mixed allogeneic reactions and enhanced fitness during early ontogeny. BMC Evol. Biol. 8, 126–126. https://doi.org/10.1186/1471-2148-8-126 (2008).CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    12.Puill-Stephan, E., Willis, B., van Herwerden, L. & van Oppen, M. Chimerism in wild adult populations of the broadcast spawning coral Acropora millepora on the Great Barrier Reef. PLoS One 4, e7751. https://doi.org/10.1371/journal.pone.0007751 (2009).ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    13.Hoeg, J. T. & Lutzen, J. Life cycle and reproduction in the Cirripedia, Rhizocephala. Oceanogr. Mar. Biol. Annu. Rev. 33, 427–485 (1995).
    Google Scholar 
    14.Gianasi, B. L., Hamel, J. F. & Mercier, A. Full allogeneic fusion of embryos in a holothuroid echinoderm. Proc. R. Soc. Lond. B 285, 1–7. https://doi.org/10.1098/rspb.2018.0339 (2018).CAS 
    Article 

    Google Scholar 
    15.Rinkevich, B. Human natural chimerism: An acquired character or a vestige of evolution?. Hum. Immunol. 62, 651–657. https://doi.org/10.1016/S0198-8859(01)00249-X (2001).CAS 
    Article 
    PubMed 

    Google Scholar 
    16.Gill, D. E., Chao, L., Perkins, S. L. & Wolf, J. B. Genetic mosaicism in plants and clonal animals. Annu. Rev. Ecol. Syst. 26, 423–444 (1995).Article 

    Google Scholar 
    17.Biesecker, L. G. & Spinner, N. B. A genomic view of mosaicism and human disease. Nat. Rev. Genet. 14, 307–320 (2013).CAS 
    Article 

    Google Scholar 
    18.Devlin-Durante, M. K., Miller, M. W., Precht, W. F. & Baums, I. B. How old are you? Genet age estimates in a clonal animal. Mol. Ecol. 25, 5628–5646. https://doi.org/10.1111/mec.13865 (2016).CAS 
    Article 
    PubMed 

    Google Scholar 
    19.Dubé, C. E., Planes, S., Zhou, Y., Berteaux-Lecellier, V. & Boissin, E. On the occurrence of intracolonial genotypic variability in highly clonal populations of the hydrocoral Millepora platyphylla at Moorea (French Polynesia). Sci. Rep. 7, 1–10. https://doi.org/10.1038/s41598-017-14684-3 (2017).CAS 
    Article 

    Google Scholar 
    20.Maier, E., Buckenmaier, A., Tollrian, R. & Nürnberger, B. Intracolonial genetic variation in the scleractinian coral Seriatopora hystrix. Coral Reefs 31, 505–517. https://doi.org/10.1007/s00338-011-0857-9 (2012).ADS 
    Article 

    Google Scholar 
    21.Schweinsberg, M., Weiss, L. C., Striewski, S., Tollrian, R. & Lampert, K. P. More than one genotype: How common is intracolonial genetic variability in scleractinian corals? Mol. Ecol. 24, 2673–2685. https://doi.org/10.1111/mec.13200 (2015).Article 
    PubMed 

    Google Scholar 
    22.van Oppen, M. J., Souter, P., Howells, E. J., Heyward, A. & Berkelmans, R. Novel genetic diversity through somatic mutations: Fuel for adaptation of reef corals? Diversity 3, 405–423 (2011).Article 

    Google Scholar 
    23.Rinkevich, B. A critical approach to the definition of Darwinian units of selection. Biol. Bull. 199, 231–240. https://doi.org/10.2307/1543179 (2000).CAS 
    Article 
    PubMed 

    Google Scholar 
    24.Rinkevich, B. The apex set-up for the major transitions in individuality. Evol. Biol. 46, 217–228. https://doi.org/10.1007/s11692-019-09481-x (2019).Article 

    Google Scholar 
    25.Santelices, B. How many kinds of individual are there? Trends Ecol. Evol. 14, 152–155. https://doi.org/10.1016/S0169-5347(98)01519-5 (1999).CAS 
    Article 
    PubMed 

    Google Scholar 
    26.Pineda-Krch, M. & Lehtilä, K. Costs and benefits of genetic heterogeneity within organisms. J. Evol. Biol. 17, 1167–1177. https://doi.org/10.1111/j.1420-9101.2004.00808.x (2004).CAS 
    Article 
    PubMed 

    Google Scholar 
    27.Rinkevich, B. Quo vadis chimerism? Chimerism 2, 1–5. https://doi.org/10.4161/chim.14725 (2011).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    28.Rinkevich, B. & Yankelevich, I. Environmental split between germ cell parasitism and somatic cell synergism in chimeras of a colonial urochordate. J. Exp. Biol. 207, 3531–3536. https://doi.org/10.1242/jeb.01184 (2004).Article 
    PubMed 

    Google Scholar 
    29.Raymundo, L. J. & Maypa, A. P. Getting bigger faster: Mediation of size-specific mortality via fusion in juvenile coral transplants. Ecol. Appl. 14, 281–295. https://doi.org/10.1890/02-5373 (2004).Article 

    Google Scholar 
    30.Rinkevich, B., Shaish, L., Douek, J. & Ben-Shlomo, R. Venturing in coral larval chimerism: A compact functional domain with fostered genotypic diversity. Sci. Rep. 6, 19493. https://doi.org/10.1038/srep19493 (2016).ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    31.Rinkevich, B. Coral chimerism as an evolutionary rescue mechanism to mitigate global climate change impacts. Glob. Chang Biol. 25, 1198–1206. https://doi.org/10.1111/gcb.14576 (2019).ADS 
    Article 

    Google Scholar 
    32.Amar, K.-O., Chadwick, N. E. & Rinkevich, B. Coral planulae as dispersion vehicles: Biological properties of larvae released early and late in the season. Mar. Ecol. Prog. Ser. 350, 71–78. https://doi.org/10.3354/meps07125 (2007).ADS 
    Article 

    Google Scholar 
    33.Rinkevich, B. Immunology of human implantation: From the invertebrate’s point of view. Hum. Reprod. 13, 455–459. https://doi.org/10.1093/humrep/13.2.503 (1998).CAS 
    Article 
    PubMed 

    Google Scholar 
    34.González, A. V. & Santelices, B. Frequency of chimerism in populations of the kelp Lessonia spicata in central Chile. PLoS One 12, 1–20. https://doi.org/10.1371/journal.pone.0169182 (2017).CAS 
    Article 

    Google Scholar 
    35.Nozawa, Y. & Hirose, M. When does the window close? The onset of allogeneic fusion 2–3 years post-settlement in the scleractinian coral, Echinophyllia aspera. Zool. Stud. 50, 396 (2011).
    Google Scholar 
    36.Puill-Stephan, E., van Oppen, M. J. H., Pichavant-Rafini, K. & Willis, B. L. High potential for formation and persistence of chimeras following aggregated larval settlement in the broadcast spawning coral, Acropora millepora. Proc. R. Soc. Lond. B Biol. Sci. 279, 699–708. https://doi.org/10.1098/rspb.2011.1035 (2012).CAS 
    Article 

    Google Scholar 
    37.Frank, U., Oren, U., Loya, Y. & Rinkevich, B. Alloimmune maturation in the coral Stylophora pistillata is achieved through three distinctive stages, 4 months post-metamorphosis. Proc. R. Soc. Lond. B Biol. Sci. 264, 99–104. https://doi.org/10.1098/rspb.1997.0015 (1997).ADS 
    Article 

    Google Scholar 
    38.Rinkevich, B. The branching coral Stylophora pistillata: Contribution of genetics in shaping colony landscape. Isr. J. Zool. 48, 71–82. https://doi.org/10.1560/BCPA-UM3A-MKBP-HGL2 (2002).Article 

    Google Scholar 
    39.Highsmith, R. Reproduction by fragmentation in corals. Mar. Ecol. Prog. Ser. 7, 207–226. https://doi.org/10.3354/meps007207 (1982).ADS 
    Article 

    Google Scholar 
    40.Barfield, S., Aglyamova, G. V. & Matz, M. V. Evolutionary origins of germline segregation in Metazoa: Evidence for a germ stem cell lineage in the coral Orbicella faveolata (Cnidaria, Anthozoa). Proc. R. Soc. Lond. B Biol. Sci. 283, 20152128. https://doi.org/10.1098/rspb.2015.2128 (2016).CAS 
    Article 

    Google Scholar 
    41.Chang, E. S., Orive, M. E. & Cartwright, P. Nonclonal coloniality: Genetically chimeric colonies through fusion of sexually produced polyps in the hydrozoan Ectopleura larynx. Evol. Lett. 2, 442–455. https://doi.org/10.1002/evl3.68 (2018).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    42.Hancock, J. P., Goulden, N. J., Oakhill, A. & Steward, C. G. Quantitative analysis of chimerism after allogeneic bone marrow transplantation using immunomagnetic selection and fluorescent microsatellite PCR. Leukemia 17, 247–251. https://doi.org/10.1038/sj.leu.2402759 (2003).CAS 
    Article 
    PubMed 

    Google Scholar 
    43.Broestl, L., Rubin, J. B. & Dahiya, S. Fetal microchimerism in human brain tumors. Brain Pathol. 28, 484–494. https://doi.org/10.1111/bpa.12557 (2018).CAS 
    Article 
    PubMed 

    Google Scholar 
    44.Olsen, K. C., Moscoso, J. A. & Levitan, D. R. Somatic mutation is a function of clone size and depth in orbicella reef-building corals. Biol. Bull. 236, 1–12. https://doi.org/10.1086/700261 (2019).CAS 
    Article 
    PubMed 

    Google Scholar 
    45.Schweinsberg, M., Tollrian, R. & Lampert, K. P. Inter- and intra-colonial genotypic diversity in hermatypic hydrozoans of the family Milleporidae. Mar. Ecol. 38, 1–11. https://doi.org/10.1111/maec.12388 (2017).Article 

    Google Scholar 
    46.Santelices, B., Alvarado, J. L. & Flores, V. Size increments due to interindividual fusions: How much and for how long? J. Phycol. 46, 685–692. https://doi.org/10.1111/j.1529-8817.2010.00864.x (2010).Article 

    Google Scholar 
    47.Rinkevich, B. & Weissman, I. L. Chimeras vs genetically homegeneous individuals: Potential fitness costs and benefits. Oikos 63, 119–124 (1992).Article 

    Google Scholar 
    48.Mizrahi, D., Navarrete, S. A. & Flores, A. A. V. Groups travel further: Pelagic metamorphosis and polyp clustering allow higher dispersal potential in sun coral propagules. Coral Reefs 33, 443–448. https://doi.org/10.1007/s00338-014-1135-4 (2014).ADS 
    Article 

    Google Scholar 
    49.Lambert, N. C. et al. Quantification of maternal microchimerism by HLA-specific real-time polymerase chain reaction: Studies of healthy women and women with scleroderma. Arthritis Rheumatol. 50, 906–914. https://doi.org/10.1002/art.20200 (2004).CAS 
    Article 

    Google Scholar 
    50.Magor, B. G., De Tomoso, A., Rinkevich, B. & Weissman, I. L. Allorecognition in colonial tunicates: Protection against predatory cell lineages? Immunol. Rev. 167, 69–79. https://doi.org/10.1111/j.1600-065x.1999.tb01383.x (1999).CAS 
    Article 
    PubMed 

    Google Scholar 
    51.Duerden, J. E. Aggregated colonies in madreporarian corals. Am. Nat. 34, 461–471 (1902).Article 

    Google Scholar 
    52.Barki, Y., Gateño, D., Graur, D. & Rinkevich, B. Soft-coral natural chimerism: A window in ontogeny allows the creation of entities comprised of incongruous parts. Mar. Ecol. Prog. Ser. 231, 91–99. https://doi.org/10.3354/meps231091 (2002).ADS 
    Article 

    Google Scholar 
    53.Linden, B., Huisman, J. & Rinkevich, B. Circatrigintan instead of lunar periodicity of larval release in a brooding coral species. Sci. Rep. 8, 5668. https://doi.org/10.1038/s41598-018-23274-w (2018).ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    54.Shefy, D., Shashar, N. & Rinkevich, B. The reproduction of the Red Sea coral Stylophora pistillata from Eilat: 4-decade perspective. Mar. Biol. 165, 27. https://doi.org/10.1007/s00227-017-3280-0 (2018).Article 

    Google Scholar 
    55.Shafir, S., Van Rijn, J. & Rinkevich, B. Steps in the construction of underwater coral nursery, an essential component in reef restoration acts. Mar. Biol. 149, 679–687. https://doi.org/10.1007/s00227-005-0236-6 (2006).Article 

    Google Scholar 
    56.Rinkevich, B. & Loya, Y. The reproduction of the Red Sea coral Stylophora pistillata. I. Gonads and planulae. Mar. Ecol. Prog. Ser. 1, 133–144 (1979).ADS 
    Article 

    Google Scholar 
    57.Santelices, B. Mosaicism and chimerism as components of intraorganismal genetic heterogeneity. J. Evol. Biol. 17, 1187–1188. https://doi.org/10.1111/j.1420-9101.2004.00813.x (2004).CAS 
    Article 
    PubMed 

    Google Scholar 
    58.Graham, D. E. The isolation of high molecular weight DNA from whole organisms or large tissue masses. Anal. Biochem. 85, 609–613. https://doi.org/10.1016/0003-2697(78)90262-2 (1978).CAS 
    Article 
    PubMed 

    Google Scholar 
    59.Douek, J., Barki, Y., Gateño, D. & Rinkevich, B. Possible cryptic speciation within the sea anemone Actinia equina complex detected by AFLP markers. Zool. J. Linn. Soc. 136, 315–320. https://doi.org/10.1046/j.1096-3642.2002.00034.x (2002).Article 

    Google Scholar 
    60.Banguera-Hinestroza, E., Saenz-Agudelo, P., Bayer, T., Berumen, M. L. & Voolstra, C. R. Characterization of new microsatellite loci for population genetic studies in the smooth cauliflower coral (Stylophora sp.). Conserv. Genet. Resour. 5, 561–563. https://doi.org/10.1007/s12686-012-9852-x (2013).Article 

    Google Scholar 
    61.Diwan, N. & Cregan, P. B. Automated sizing of fluorescent-labeled simple sequence repeat (SSR) markers to assay genetic variation in soybean. Theor. Appl. Genet. 95, 723–733. https://doi.org/10.1007/s001220050618 (1997).CAS 
    Article 

    Google Scholar 
    62.Hearne, C. M., Ghosh, S. & Todd, J. A. Microsatellites for linkage analysis of genetic traits. Trends Genet. 8, 288–294. https://doi.org/10.1016/0168-9525(92)90256-4 (1992).CAS 
    Article 
    PubMed 

    Google Scholar  More

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    Functional diversity of Himalayan bat communities declines at high elevation without the loss of phylogenetic diversity

    Study area and sampling locationsWe conducted this study in Kedarnath Wildlife Sanctuary (30° 25′–30° 41′ N, 78° 55′–79° 22′ E), located in Uttarakhand state in the western Himalayas of India. This sanctuary covers a broad elevational gradient from 1400 to 4000 m above sea level (asl) (Fig. 1), with corresponding changes in habitat types: from Himalayan moist temperate forests dominated by Quercus spp. at low elevations, to sub-alpine forests dominated by Rhododendron spp. and alpine meadows at high elevations34. This sanctuary is known to harbour 26 species of bats35.Figure 1Map of India showing the location of the study area, Kedarnath Wildlife Sanctuary, and the sampling locations within the study area. Elevation is in m asl. The map was created using QGIS (v 3.6.3-Noosa) (QGIS Geographical Information System, www.qgis.org). Please note that the geographical boundaries represented in the map may contain areas considered disputed.Full size imageWe sampled at four locations spanning an elevational gradient of 2200 m. Sampling points within each location were spread across the elevations mentioned in parentheses: Mandal (1500–1800 m), Ansuya (2000–2200 m), Chopta (2700–3000 m) and Tungnath (3300–3700 m) (Fig. 1). Sampling was conducted between late-March and mid-May in 2018 and 2019, starting at lower elevations and then moving to higher elevations. This sampling duration coincides with summer in the Himalaya. To comprehensively sample the bat diversity, we employed a combination of automated ultrasonic recorders and capture sampling using mist-netting. Fieldwork was approved by the Internal Committee for Ethics and Animal Welfare, Institute for Zoo and Wildlife Research (approval no. 2018-06-01), and conducted under a permit issued by the Uttarakhand State Forest Department, Government of India (permit no. 2261/5-6).Sampling strategyFor acoustic sampling, we placed full spectrum passive ultrasonic recorders (SongMeter SM4BAT, Wildlife Acoustics, Maynard, MA, USA) in different habitat types (open, forest edge, and forest) at each elevation (hereafter, “passive recordings”). The recorders were programmed to record bat calls for two consecutive nights at each sampling point, from dusk to dawn (9–10 h/night), using a sample rate of 500 kHz/s, an amplitude threshold of 16 dB and a frequency threshold of 5 kHz. The dominant habitats at Ansuya and Tungnath are montane evergreen forests and alpine meadows respectively, therefore only these habitats were sampled at these elevations. The exact number of sampling points per habitat for each elevation is given in Table S1. On separate days after completing acoustic sampling at a site, we set up nylon and monofilament mist nets of 4, 6 or 9 m length, 16 × 16 and 19 × 19 mesh sizes (Ecotone GOC, Sopot, Poland) for four hours following dusk (starting between 18.30 h in early summer and 19.30 h in late summer). The captured bats were handled and measured following the guidelines of the American Society of Mammalogists36. To further refine identification in light of the paucity of taxonomic knowledge in the region, we collected only one specimen each of taxonomically-challenging species in accordance with our field research permit. We measured body mass (accuracy 0.1 g) using a spring balance (Pesola, Schindellegi, Switzerland), and forearm length (accuracy 0.01 mm) with vernier calipers (Swiss Precision Instruments SPI Inc., Melville, NY, USA). Next, we gently stretched the left wing and placed the live animal perpendicular to the background of a graph sheet of 1 × 1 cm grids. We photographed the outstretched wing using a Nikon D3400 DSLR camera at 55 mm zoom from a distance of about 90 cm. Subsequently, we released the bats and recorded their echolocation calls at a distance of 5 to 10 m using a handheld ultrasonic detector (Anabat Walkabout, Titley Scientific, Brendale, QLD, Australia) and saved them as audio files of .wav format. These recordings (henceforth referred to as “reference recordings”) formed the dataset used to develop a call library for identification.Call classifier and analysis of passive recordingsReference recordings from 2018 and 2019 were labelled using Raven Pro 1.5 (Cornell Lab of Ornithology, Ithaca, NY, USA) to generate a dataset of acoustic parameters for identification. We visualized calls using a spectrogram with Hanning window, size 1024 samples with 95% overlap. From each recording, we selected 10 clear pulses and measured the following parameters: average peak frequency, maximum peak frequency, centre frequency, minimum peak frequency, peak frequency at the start and end of the call, bandwidth at 90% peak amplitude, average entropy, and call duration. All frequency variables were measured in Hz and time variables in ms. We used the peak frequency contour to determine start and end frequencies and also used bandwidth at 90% peak amplitude because higher frequencies attenuate quickly with distance from the emitting bat (causing changes to the bandwidth), and these measures are therefore more reliable in field circumstances. Using this labelled call library as a training dataset, we trained a fine K-nearest neighbours classifier using supervised learning within the ‘Classification Learner’ app in MATLAB (Mathworks, Inc., Natick, MA, USA). We further employed fivefold cross-validation to obtain estimates of the accuracy of each classifier in assigning calls to species. Using these pairwise values of relative accuracy (%), we generated confusion matrices for these classifiers where the species identities were represented in the columns and rows as ‘True’ and ‘Predicted’ classes, respectively. Any species with classification accuracy below 85% was clubbed with possible confusion species into a “sonotype”, to improve accuracy of the classifier in the most conservative way possible (Fig. S4). The complete list of sonotypes and their mean echolocation call parameters is presented in Table 1. The classifier identified these sonotypes with  > 80% accuracy, with the exception of Miniopterus and the Plecotus type B call (which, however, we could manually identify because of their call structures and frequencies). For all subsequent analyses on functional diversity and phylogenetic diversity, we used these sonotypes to ensure accurate identification.Table 1 Trait matrix of the sonotypes in our assemblage (FA in mm; fmaxe, pfc.min, and pfc.max in kHz; Duration in ms).Full size tableNext, we analysed the passive recordings manually in Raven Pro. We labelled calls in subsets of 15 min per hour of the passive recordings. For each hour, the 15-min subsets were in the time windows 0–5 min, 20–25 min and 40–45 min, so as to spread out our sampling window across the hour. Following labelling, we obtained sonotype IDs using the classifier, and then verified them manually by visual comparison to the call library to improve discrimination. For every 5-min interval, we made a presence-absence matrix where 1 indicated the presence of a sonotype and 0 indicated its absence. The number of 5-min intervals in which a sonotype was detected (hereby “acoustic detections”) was summed up for each sampling point. We measured the relative abundance of sonotypes as the proportion of its total number of acoustic detections relative to the total number of acoustic detections of all sonotypes in a given elevational location. The use of such a presence-absence framework is akin to ‘Acoustic Activity Index’37 which represents a relatively less biased index of activity that is less affected by differences in vocal behaviour and echolocation frequencies of different species of bats.Assessing detectabilityTo assess the completeness of our species inventory, we estimated the species richness of each sampling point using the first-order Jackknife Estimator (Jack 1)38. Jack 1 is a nonparametric procedure for estimating species richness using presence or absence of a species in a given plot rather than its abundance39. Mean species detectability was calculated as the ratio of the observed to estimated species richness for different sampling point-year combinations40,41. We then assessed whether this mean species detectability depended on the habitat type, year, and location by fitting a linear model with the above-mentioned variables as fixed factor predictors and the mean detectability as a response. We also determined species-level detectability by following the approach of Kéry and Plattner42. If a sonotype was detected by mistnetting or acoustic sampling in sampling event i, we modelled its probability to be detected in sampling event i + 1. For each sonotype, we fitted a generalized linear mixed-effects model (logit link and binomial error distribution) with detection/non-detection as the response variable, and habitat type, location, and year as the fixed factor predictors. Site and species were included as random intercepts. The significance of the fixed effects was assessed with the Likelihood Ratio Test. This test allows one to choose the best of two nested models by assessing the ratio of their likelihoods. The significance of the random effect (species) was assessed by applying a parametric bootstrap (number simulations = 100) to the model with and without the random effect, using the function bootMer of ‘lme4’ package. In short, a parametric bootstrap consists of fitting the model to the data and bootstrapping the obtained residuals. For these and other statistical analyses we used R version 4.0.2 (R Core Team 2020).Taxonomic diversityWe calculated rarefied incidence-based species richness (SR) and Simpson diversity extrapolated to 50 sampling events (the number of sampling events in Mandal) using the ‘iNEXT’ R package43. The calculations were performed on a sonotype-by-sampling point presence-absence matrix with detections from both acoustic sampling and mistnetting pooled together. In the matrix, columns represented sampling units (Night 1, Night 2 and so on) and rows represented sonotype. By using sonotypes instead of species, we likely underestimated the SR, but this underestimation was uniform across elevations and is unlikely to change the pattern of SR with elevation.Functional diversityOur functional trait matrix (Table 1) comprised seven morphological and acoustic traits involved in guild classification, foraging and micro-habitat preferences (abbreviation followed by units): forearm length (FA, mm), aspect ratio (AR), wing loading (WL, N/m2), tip-shape index (I), echolocation peak frequency/frequency of maximum energy (FmaxE, kHz), minimum and maximum frequencies of the peak frequency contour (pfc.min and pfc.max, kHz) and call duration (D, ms). FA was measured in the field using vernier calipers. We used ImageJ (National Institutes of Health, Bethesda, MD, USA)44 to measure total wing area, areas of hand and arm wings and the wingspan from the standardised wing photos that were taken in the field. We calculated AR, WL, and I from these measurements following the equations given in Norberg and Rayner45. AR and WL both represent parameters that are correlated with flight aerodynamics and behaviour. I is influenced by the shape of the wing tip where values of 1 and above indicate broad, triangular tips, while those below 1 indicate acute wing tips. The four acoustic traits represent the shape of the echolocation call and they were measured from the reference recordings using Raven Pro, as described above.We first calculated the means for each of the seven traits across all species within a sonotype (thus obtaining one average trait value for each sonotype) (Table 1) and then used those to compute four multivariate functional diversity (FD) indices: functional richness (FRic), divergence (FDiv), evenness (FEve)46, and dispersion (FDis)47, using the function dbFD() in the ‘FD’ R package47. Our FD measures are unlikely to be underestimated due to the pooling of species into sonotypes because these species were similar in acoustic and morphological traits. FRic is the convex hull volume of the traits of species present in a community, measured in the multidimensional trait space. This measurement is not weighted by abundance, relative abundance or biomass of the species in the community, but, it is standardised such that it ranges from 0 to 1. FDiv reflects the distribution of abundance across taxa (sonotypes in our case) in the functional space. High FDiv means the taxa with extreme trait values are more abundant in a community whereas low FDiv means that those with the trait values close to the centre of the functional space are more abundant48. FEve, on the other hand, measures the evenness in the abundance distribution of taxa in the functional space. FEve is high when all taxa have similar abundances, and it is low when some functional groups are abundant while others are rare48. Lastly, FDis is measured as the mean distance of all taxa to the abundance-weighted trait community centroid. We performed two sets of analyses: one using the number of mistnet captures as a proxy for relative abundance, and another using the number of detections of different sonotypes in 5-min intervals in the passive recordings as a proxy of relative abundance. We did not pool acoustic detections and mistnet captures as they have inherently different detection probabilities and measure different entities (relative number of detections vs. number of captured individuals). Owing to rhinolophid bats at lower elevations being taxonomically and functionally different from the remaining species pool, we performed another set of FD calculations, excluding the four rhinolophid species and using acoustic detections as relative abundance. One species, Tadarida teniotis was commonly detected at all elevations on acoustic recorders, but we were unable to capture it as it foraged high above the ground, and thus were unable to collect morphological trait data. Additionally, in using acoustic detections as a measure of relative abundance, we had to exclude the non-echolocating pteropodid bat Sphaerias blanfordi which was caught only once at Chopta. Therefore, our FD values are likely systematically underestimated across all elevational communities, which does not affect the comparison of community composition across elevations.Phylogenetic diversityUsing the nexus file of a published phylogeny49, we pruned the tree to represent species in the 14 sonotypes. For each of these types, we chose the species most commonly mist-netted as representative of its group. Published DNA sequences are lacking for some of the species in this region, so we chose their closest relatives from the phylogeny instead. Thus, we made the following replacements: (a) Nyctalus leisleri represented the AMN sonotype, (b) Eptesicus serotinus represented the EH sonotype, (c) Murina aurata for Murina sonotype, (d) Myotis longipes for MS sonotype, (e) Pipistrellus javanicus for MP sonotype, and (f) Plecotus turkmenicus for Plecotus sonotype. After pruning the tree, we calculated three indices of phylogenetic diversity using the ‘picante’ R package50: Faith’s phylogenetic diversity (PD), Mean pairwise distance (MPD) and Mean nearest-taxon distance (MNTD). Faith’s PD is a measure of phylogenetic richness which is obtained by summing the branch lengths of the tree connecting the species in the community. MPD and MNTD measure phylogenetic dispersion of communities; whereas MPD measures the average phylogenetic distance among all the taxa in a community, MNTD measures the same for the nearest neighbouring taxa51. We weighted MPD and MNTD by relative abundance of the sonotypes in each community (like FD, the number of detections in five-minute intervals in the passive recordings was used as a proxy of relative abundance).Null model testingAs FD and PD are strongly correlated to species richness52, we used a null model to assess whether the observed was significantly different than expected due to chance alone. We produced the null distribution of each FD and PD index by randomizing the community matrix 999 times using the ‘independent swap’ method53,54, so as to preserve the species richness at each site and the number of sites in which each species can be found. Our randomization was further constrained by elevation, so that the abundances were randomized among the sampling points within each elevation. The null model allows for calculation of an effect size (difference between the observed value and mean of the null distribution). Given the range of FD and PD values, the effect sizes are not comparable across communities with vastly different species richness55. Therefore, standardized effect sizes (SES) of each index were calculated at each site as the difference between the observed value and the mean of the null distribution, divided by the standard deviation of the null distribution. SES  > 1 and SES  More

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    Cooperative herbivory between two important pests of rice

    Plants and insectsRice (Oryza sativa) cultivar Minghui63 was used in this study. Rice plants were grown in a greenhouse at 27 ± 3 °C with 75 ± 10% RH (relative humidity) and a photoperiod of 16:8 h L:D (light:dark). The cultivation of rice plants followed the same procedure as described previously27. Plants were used for experiments when they were at the tillering stage, which occurred about 44–49 days after sowing.C. suppressalis larvae were reared on an artificial diet as described70. Ten percent honey water solution was provided to supply nutrition for the adults. N. lugens were maintained on a BPH-susceptible rice variety Taichung Native 1 (TN1)38. T. japonicum were obtained from Keyun Industry Co., Ltd (Jiyuan, China). Newly emerged adult wasps were maintained in glass tubes (3.5 cm diameter, 20 cm height) and supplied with 10% honey water solution as a food source and were maintained for at least 6 h to ensure free mating, before females were used for the following experiments. All three species were maintained in climatic chambers at 27 ± 1 °C, 75 ± 5% RH, and a photoperiod of 16:8 h L:D.Performance of caterpillars on insect-infested rice plantsMultiple types of rice plants were prepared: (i) uninfested plants, meaning that potted rice plants remained intact without insect infestation; (ii) SSB-infested plants, each potted rice plant was artificially infested with one 3rd instar SSB larva that had been starved for >3 h for 48 h; (iii) BPH-infested plants, each potted rice plant was artificially infested with a mix of fifteen 3rd and 4th instars BPH nymphs for 48 h; (iv) SSB/BPH-infested plants, each potted rice plant was simultaneously infested with one SSB larva and 15 BPH nymphs for 48 h; (v) SSB → BPH-infested plants, each potted rice plant was artificially infested with one SSB larvae alone for the first 24 h, then 15 BPH nymphs were additionally introduced for another 24 h; (vi) BPH → SSB-infested plants, namely each potted rice plant was artificially infested with 15 BPH nymphs for the first 24 h, then one SSB larvae were additionally introduced for another 24 h. Plant treatments were conducted as described in detail in our previous study27. During herbivory treatment, the uninfested plants were placed in a separate room to avoid possible volatile-mediated interference. During the subsequent bioassays, both SSB caterpillar and BPH nymphs remained in or on the rice plants.Two bioassays were conducted to test the performance of C. suppressalis larvae feeding on differently treated rice plants. The first bioassay included the plant treatments i, ii, iii, and vi, and the second bioassay included the plant treatments i, ii, v, and vi. Three 2-day-old larvae of C. suppressalis were gently introduced onto the middle stem of each rice plant using a soft brush. The infested rice plants were then placed in climatic chambers at 27 ± 1 °C, 75 ± 5% relative humidity, and a photoperiod of 16:8 h L:D. The C. suppressalis larvae were retrieved from the rice plants after 7 days feeding, and they were weighed on a precision balance (CPA2250, Sartorius AG, Germany; readability = 0.01 mg). The mean weight of the three caterpillars on each plant was considered as one biological replicate. The experiment was repeated four times using different batches of plants and herbivores, resulting in a total of 30–46 biological replicates for each treatment.Oviposition-preferences of C. suppressalis females choosing among differently infested rice plantsGreenhouse experimentIn the greenhouse, seven choice tests were conducted with C. suppressalis females including (i) SSB-infested plants versus uninfested plants; (ii) BPH-infested plants versus uninfested plants; (iii) SSB/BPH-infested plants versus uninfested plants; (iv) SSB-infested plants versus BPH-infested plants; (v) SSB-infested plants versus SSB/BPH-infested plants; (vi) BPH-infested plants versus SSB/BPH-infested plants; and (vii) the test in which C. suppressalis females were exposed to all four types of rice plants. The experiments were performed as described in detail by Jiao et al.30. In brief, four potted plants were positioned in the four corners of a cage (80 × 80 × 100 cm) made of 80-mesh nylon nets for each test. For paired comparisons, two potted plants belonging to the same treatment were placed in opposite corners of each age, and in the test with four types of rice plants, each type of plant was positioned in one of the four corners of each cage. Five pairs of freshly emerged moths (less than 1 day) were released in each cage, and a clean Petri dish (9 cm diameter) containing a cotton ball soaked with a 10% honey solution was placed in the center of the cage as food source. After 72 h, the number of individual eggs on each plant were determined. The experiment was conducted in a greenhouse at 27 ± 3 °C, 65 ± 10% RH, and a photoperiod of 16:8 h L:D. Each choice test was repeated with 9–11 times (replicates).Field cage experimentThe oviposition preference of SSB females was further assessed in a field near Langfang City (39.58° N, 116.48° E), China. Four choice tests were conducted: (i) SSB-infested plants versus uninfested plants; (ii) BPH-infested plants versus uninfested plants; (iii) SSB/BPH-infested plants versus uninfested plants; and (iv) SSB/BPH-infested plants versus SSB-infested plants. The treated rice plants were prepared as described above and were transplanted into experimental plots (1.5 × 1.5 m). For each pairwise comparison, six plots of rice plants were covered with a screened cage (8 × 5 × 2.5 m) made of 80-mesh nylon net to prevent moths from entering or escaping. Each of the six plots contained nine rice plants of a particular treatment, with three plots per cage representing the same treatment. Plots were separated by a 1 m buffer and they were alternately distributed in a 3 × 2 grid arrangement in each cage (Supplementary Fig. 4). Approximately 50 mating pairs of newly emerged C. suppressalis adults ( More

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    Seasonal diets supersede host species in shaping the distal gut microbiota of Yaks and Tibetan sheep

    Yak and Tibetan sheep thrive under a co-grazing system on the QTP and/or are fed with the same materials; this offers an excellent opportunity to compare the gut microbiota in different host species which share a similar diet. In addition, the grazing systems on the QTP undergo seasonal diets changes in terms of pasture location and forage composition, especially between winter and summer. This presents a good natural “treatment” which helps vary the diets of the yak and Tibetan sheep populations. In the current study, based on a more substantial sample size than the previous study1, we found that diet and environment (represented by seasons winter and summer) superseded host genetics to the family level. That is to say that the gut microbiota of the two animal species showed convergent adaptation to high altitude and harsh environment in QTP, but this convergence had seasonal diets characteristics. These findings may provide a cautionary note for ongoing efforts to link host genetics to gut microbiota composition and function and would provide some food for thought in the breeding of these two livestock groups.The mammalian gut microbiota is acquired from the environment starting at birth, and its assembly and composition is largely shaped by factors such as age, diet, lifestyle, hygiene, and disease state. Researchers subconsciously believe that host species play a greater role than environmental factors when it comes to shaping gut microbiota, especially when there is a large taxonomical difference between the host species. So far, the vast majority of research have focused on the ruminal ecosystem because the rumen is primary site of feed fermentation15,16,17. It is rare to find studies that directly compare the gut microbiota of different species. However, evidence showed that energetically-important microbial products, including VFA (10–13% of total GIT VFA) are produced in the ruminant distal gut3. Hence, it is important to study the composition of distal gut microbiota of ruminants.In this study, at the phylum level, the gut microbiota composition in both groups of livestock was dominated by Bacteroidetes and Firmicutes, which was in agreement with previous reports concerning the yak18. At the same time our result consistently with other study in dairy cows that two dominated phyla Bacteroidetes and Firmicutes found in fecal samples in different seasons were abundant19,20. Firmicutes and Bacteroidetes are responsible for digestion of carbohydrates and proteins, Members of Bacteroidetes having extremely stronger ability to degrade crystalline cellulose. The previous report showed that intestinal microbiome plays an important role in digestion and absorption of the food, and maintaining animals’ health21,22. Intestinal tracts of the ruminants are rich in symbiotic bacteria that helps the body digest plant fibers23,24. Glycans are processed by the distal gut microbiota, generating biologically significant short-chain fatty acids (SCFAs, predominantly acetate, butyrate, and propionate), which serve as the principal energy source for colonocytes25. Fibers may be involved in the regulation of food intake and energy balance via the SCFA-mediated modulation of the secretion of gut hormones26. The higher abundance of Firmicutes and Bacteroidetes in yak may be associated with high-energy consumption at high altitude18.It is worth noting that, at the family level, the dominant genera (Unclassified Ruminococcaceae, Bacteroidaceae, Unclassified BS11, Unclassified Prevotellaceae, Unclassified Christensenellaceae, CF231, Unclassified Mogibacteriaceae and Unclassified Paraprevotellaceae) in the intestines of yak and Tibetan sheep were more greatly influenced by season than genetics (Fig. 5). This has not previously been accurately identified, which may be because there have been few studies into the gut microbial communities of the yak and Tibetan sheep in QTP. So, to improve their husbandry, it is important in the future to study their microbiota profiles using more precise methods such as 16S full-length sequencing or metagenomic sequencing. Ruminococcaceae is a family of autochthonous and benignspecies that primarily inhabit in the caecum and the colon27. It is known that Ruminococcaceae are common in the rumen and hindgut of ruminants, capable of degrading cellulose and starch28. As a member of short chain fatty acid (SCFA) producers, Ruminococcaceae is considered to be the most important fiber and polysaccharides-degrading bacterium in the intestine of herbivores, and produces large amounts of cellulolytic enzymes, including exoglucanases, endoglucanase, glucosidases and hemicellulase29. The microbial community of Yak and Sheep is greatly influenced by alterations in dietary nutrition, Bacteroidaceae have the ability to degrade complex molecules (polysaccharides, proteins) in the intestine18, which can promote the Yak utilizes grasses as its major source of nutrition, due to shortage of grain and other nutrients. Prevotellaceae is responsible for hemicellulose, pectin and high carbohydrate food digestion30. The higher abundance of these microbes may contribute to gaining more energy, and play vital roles in the process of adaption of the hosts to the harsh natural environment15. Bacteroidales BS11 gut group are specialized to active hemicellulose monomeric sugars (e.g., xylose, fucose, mannose and rhamnose) fermentation and short-chain fatty acid (e.g., acetate and butyrate) production that are vital for ruminant energy31. The Bacteroidales BS11 was positively correlated with some metabolites that are involved in amino acid metabolism and biosynthesis, as well as the metabolism of energy sources, such as starch, sucrose, and galactose32.At the genus level, 5-7N15 was most abundant in winter in both animals, on the contrary, the Provotella was predominate. Here, our results indicated that seasonal diets change superseded variations derived from genetic differences between the host species, even though the yak and Tibetan sheep are very different, both taxonomically and in terms of body size. In summer, the forage grass on the Qinghai-Tibet Plateau is dominated by Agropyron cristatum, Elymus nutans, Festuca ovina, Kobresia humilis, Poa pratensis, Stipa aliena, Kobresia pygmaea, Oxytropis biflora, Saussurea hieracioides, Astragalus arnoldii Hemsl. In winter, the main forage was Brachypodium sylvaticum. Carex crebra, Trisetum spicatum and Bupleurum smithii. Stipa has both high palatability and nutritional value, with a high content of crude protein, crude fat, and nitrogen- free extract, and low levels of crude fiber33. The levels of crude protein, crude fat, and nitrogen-free extracts of Brachypodium sylvaticum. Carex crebra, Trisetum spicatum and Bupleurum smithii were lower than that of Stipa, whereas the content of crude fiber was higher than that of Stipa34. Crude protein is the main nutrient of herbage. Crude fat and nitrogen-free extracts provide heat and energy33.Lopes et al. reported that some OTUs known to be functionally relevant for fiber degradation and host development were shared across the entire gastrointestinal tract and present within the feces35. Microbial diversity increases in the distal segments of the gastrointestinal tract. Microbial fermentation appears to be reestablished in the large intestine, with the proportion of acetate, propionate and butyrate being similar to the rumen.Several explanations for this phenomenon are possible. Firstly, both the yak and Tibetan sheep are ruminants. In herbivores, the gut microbiota is dominated by Firmicutes and Bacteroides, the functions of which are related to cellulose digestion36. Therefore, ruminant microbes could possibly be more similar across species than gut microbes from elsewhere.Secondly, the yaks and Tibetan sheep in our study co-grazed from birth to death. As such, the initial gut microbiota source, responsible for populating the remainder of the gut in the months and years after the initial seeding at birth, would necessarily come from the same environment. It has been established that early life events are critical for gut microbiota development and for shaping the adult microbiota. Lifestyle and diet will further influence the composition and function of the gut microbiota. In our study, the investigated animals shared a very similar lifestyle and obtained their diets from the same source. The results revealed that sheep and yaks presented almost identical gut microbiota compositions in the winter, but by the date of collection of the summer samples they were quite different. The reason for this could be that during summer and summer there is pronounced pastoral grass growth, giving the animals more variety and choice in their diets; it is known, after all, that sheep have different diet preferences to yaks37. However, during the winter, the animals have no option but to eat the same food in order to survive until winter.Thirdly, there could be a convergent evolution of gut microbiomes in yaks and Tibetan sheep due to the extremely harsh environment in high-altitude regions1,38. When compared with their low-altitude relatives, cattle (Bos taurus) and ordinary sheep (Ovis aries), metagenomic analyses revealed significant enrichment in rumen microbial genes involving volatile fatty acid-yielding pathways in yaks and Tibetan sheep, whereas methanogenesis pathways were enriched in the cattle metagenome. Analyses of RNA transcriptomes revealed significant upregulation in 36 genes associated with volatile fatty acid transport and absorption in the ruminal epithelium of yaks and Tibetan sheep. This suggests that, aside from host genetics, long-term exposure to harsh environments has allowed the gut microbiome to adapt in order to boost health and survival. In other words, although yaks and Tibetan sheep are very different genetically, their gut microbiota could be similar due to the selection pressures of the high altitude at which they live. Meanwhile, from our data based on functional gene composition (Fig. S3), it is also worth noting that there were no groups clearly distinguished from one another, although the PERMANOVA results indicated both a host and season effect, with the interaction between them being statistically significant. Though factors such as environment and diet (represented by seasons) can trump host genetics, we could not ignore the interplay of these factors as gut microbes are a very complex community.Winter is the harshest period for the survival of yak and Tibetan sheep. To maintain the survival, it’s best to feed the animals with a high protein content. Furthermore, to get more detailed data in different seasons and various dietary habits of yak and sheep, more study should be assessed about intestinal microbiota by collecting feces. More