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    Study reveals the benefits and downside of fasting

    Low-calorie diets and intermittent fasting have been shown to have numerous health benefits: They can delay the onset of some age-related diseases and lengthen lifespan, not only in humans but many other organisms.Many complex mechanisms underlie this phenomenon. Previous work from MIT has shown that one way fasting exerts its beneficial effects is by boosting the regenerative abilities of intestinal stem cells, which helps the intestine recover from injuries or inflammation.In a study of mice, MIT researchers have now identified the pathway that enables this enhanced regeneration, which is activated once the mice begin “refeeding” after the fast. They also found a downside to this regeneration: When cancerous mutations occurred during the regenerative period, the mice were more likely to develop early-stage intestinal tumors.“Having more stem cell activity is good for regeneration, but too much of a good thing over time can have less favorable consequences,” says Omer Yilmaz, an MIT associate professor of biology, a member of MIT’s Koch Institute for Integrative Cancer Research, and the senior author of the new study.Yilmaz adds that further studies are needed before forming any conclusion as to whether fasting has a similar effect in humans.“We still have a lot to learn, but it is interesting that being in either the state of fasting or refeeding when exposure to mutagen occurs can have a profound impact on the likelihood of developing a cancer in these well-defined mouse models,” he says.MIT postdocs Shinya Imada and Saleh Khawaled are the lead authors of the paper, which appears today in Nature.Driving regenerationFor several years, Yilmaz’s lab has been investigating how fasting and low-calorie diets affect intestinal health. In a 2018 study, his team reported that during a fast, intestinal stem cells begin to use lipids as an energy source, instead of carbohydrates. They also showed that fasting led to a significant boost in stem cells’ regenerative ability.However, unanswered questions remained: How does fasting trigger this boost in regenerative ability, and when does the regeneration begin?“Since that paper, we’ve really been focused on understanding what is it about fasting that drives regeneration,” Yilmaz says. “Is it fasting itself that’s driving regeneration, or eating after the fast?”In their new study, the researchers found that stem cell regeneration is suppressed during fasting but then surges during the refeeding period. The researchers followed three groups of mice — one that fasted for 24 hours, another one that fasted for 24 hours and then was allowed to eat whatever they wanted during a 24-hour refeeding period, and a control group that ate whatever they wanted throughout the experiment.The researchers analyzed intestinal stem cells’ ability to proliferate at different time points and found that the stem cells showed the highest levels of proliferation at the end of the 24-hour refeeding period. These cells were also more proliferative than intestinal stem cells from mice that had not fasted at all.“We think that fasting and refeeding represent two distinct states,” Imada says. “In the fasted state, the ability of cells to use lipids and fatty acids as an energy source enables them to survive when nutrients are low. And then it’s the postfast refeeding state that really drives the regeneration. When nutrients become available, these stem cells and progenitor cells activate programs that enable them to build cellular mass and repopulate the intestinal lining.”Further studies revealed that these cells activate a cellular signaling pathway known as mTOR, which is involved in cell growth and metabolism. One of mTOR’s roles is to regulate the translation of messenger RNA into protein, so when it’s activated, cells produce more protein. This protein synthesis is essential for stem cells to proliferate.The researchers showed that mTOR activation in these stem cells also led to production of large quantities of polyamines — small molecules that help cells to grow and divide.“In the refed state, you’ve got more proliferation, and you need to build cellular mass. That requires more protein, to build new cells, and those stem cells go on to build more differentiated cells or specialized intestinal cell types that line the intestine,” Khawaled says.Too much of a good thingThe researchers also found that when stem cells are in this highly regenerative state, they are more prone to become cancerous. Intestinal stem cells are among the most actively dividing cells in the body, as they help the lining of the intestine completely turn over every five to 10 days. Because they divide so frequently, these stem cells are the most common source of precancerous cells in the intestine.In this study, the researchers discovered that if they turned on a cancer-causing gene in the mice during the refeeding stage, they were much more likely to develop precancerous polyps than if the gene was turned on during the fasting state. Cancer-linked mutations that occurred during the refeeding state were also much more likely to produce polyps than mutations that occurred in mice that did not undergo the cycle of fasting and refeeding.“I want to emphasize that this was all done in mice, using very well-defined cancer mutations. In humans it’s going to be a much more complex state,” Yilmaz says. “But it does lead us to the following notion: Fasting is very healthy, but if you’re unlucky and you’re refeeding after a fasting, and you get exposed to a mutagen, like a charred steak or something, you might actually be increasing your chances of developing a lesion that can go on to give rise to cancer.”Yilmaz also noted that the regenerative benefits of fasting could be significant for people who undergo radiation treatment, which can damage the intestinal lining, or other types of intestinal injury. His lab is now studying whether polyamine supplements could help to stimulate this kind of regeneration, without the need to fast.“This fascinating study provides insights into the complex interplay between food consumption, stem cell biology, and cancer risk,” says Ophir Klein, a professor of medicine at the University of California at San Francisco and Cedars-Sinai Medical Center, who was not involved in the study. “Their work lays a foundation for testing polyamines as compounds that may augment intestinal repair after injuries, and it suggests that careful consideration is needed when planning diet-based strategies for regeneration to avoid increasing cancer risk.”The research was funded, in part, by a Pew-Stewart Trust Scholar award, the Marble Center for Cancer Nanomedicine, the Koch Institute-Dana Farber/Harvard Cancer Center Bridge Project, and the MIT Stem Cell Initiative. More

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    Food for thought

    MIT graduate student Juana De La O describes herself as a food-motivated organism, so it’s no surprise that she reaches for food and baking analogies when she’s discussing her thesis work in the lab of undergraduate officer and professor of biology Adam Martin. 

    Consider the formative stages of a croissant, she offers, occasionally providing homemade croissants to accompany the presentation: When one is forming the puff pastry, the dough is folded over the butter again and again. Tissues in a developing mouse embryo must similarly fold and bend, creating layers and structures that become the spine, head, and organs — but these tissues have no hands to induce those formative movements. 

    De La O is studying neural tube closure, the formation of the structure that becomes the spinal cord and the brain. Disorders like anencephaly and craniorachischisis occur when the head region fails to close in a developing fetus. It’s a heartbreaking defect, De La O says, because it’s 100 percent lethal — but the fetus fully develops otherwise. 

    “Your entire central nervous system hinges on this one event happening successfully,” she says. “On the fundamental level, we have a very limited understanding of the mechanisms required for neural closure to happen at all, much less an understanding of what goes wrong that leads to those defects.” 

    Hypothetically speaking

    De La O hails from Chicago, where she received an undergraduate degree from the University of Chicago and worked in the lab of Ilaria Rebay. De La O’s sister was the first person in her family to go to and graduate from college — De La O, in turn, is the first person in her family to pursue a PhD. 

    From her first time visiting campus, De La O could see MIT would provide a thrilling environment in which to study.

    “MIT was one of the few places where the students weren’t constantly complaining about how hard their life was,” she says. “At lunch with prospective students, they’d be talking to each other and then just organically slip into conversations about science.”

    The department emails acceptance letters and sends a physical copy via snail mail. De La O’s letter included a handwritten note from department head Amy Keating, then a graduate officer, who had interviewed De La O during her campus visit. 

    “That’s what really sold it for me,” she recalls. “I went to my PI [principal investigator]’s office and said, ‘I have new data’” and I showed her the letter, and there was lots of unintelligible crying.” 

    To prepare her for graduate school, her parents, both immigrants from Mexico, spent the summer teaching De La O to make all her favorite dishes because “comfort food feels like home.”   

    When she reached MIT, however, the Covid-19 pandemic ground the world to a halt and severely limited what students could experience during rotations. Far from home and living alone, De La O taught herself to bake, creating the confections she craved but couldn’t leave her apartment to purchase. De La O didn’t get to work as extensively as she would have liked during her rotation in the Martin lab. 

    Martin had recently returned from a sabbatical that was spent learning a new research model; historically a fly lab, Martin was planning to delve into mouse research. 

    “My final presentation was, ‘Here’s a hypothetical project I would hypothetically do if I were hypothetically going to work with mice in a fly lab,’” De La O says. 

    Martin recalls being impressed. De La O is skilled at talking about science in an earnest and engaging way, and she dug deep into the literature and identified points Martin hadn’t considered. 

    “This is a level of independence that I look for in a student because it is important to the science to have someone who is contributing their ideas and independent reading and research to a project,” Martin says. 

    After agreeing to join the lab — news she shared with Martin via a meme — she got to work. 

    Charting mouse development

    The neural tube forms from a flat sheet whose sides rise and meet to create a hollow cylinder. De La O has observed patterns of actin and myosin changing in space and time as the embryo develops. Actin and myosin are fibrous proteins that provide structure in eukaryotic cells. They are responsible for some cell movement, like muscle contraction or cell division. Fibers of actin and myosin can also connect across cells, forming vast networks that coordinate the movements of whole tissues. By looking at the structure of these networks, researchers can make predictions about how force is affecting those tissues.

    De La O has found indications of a difference in the tension across the tissue during the critical stages of neural tube closure, which contributes to the tissue’s ability to fold and form a tube. They are not the first research group to propose this, she notes, but they’re suggesting that the patterns of tension are not uniform during a single stage of development.

    “My project, on a really fundamental level, is an atlas for a really early stage of mouse development for actin and myosin,” De La O says. “This dataset doesn’t exist in the field yet.” 

    However, De La O has been performing analyses exclusively in fixed samples, so she may be quantifying phenomena that are not actually how tissues behave. To determine whether that’s the case, De La O plans to analyze live samples.

    The idea is that if one could carefully cut tissue and observe how quickly it recoils, like slicing through a taught rubber band, those measurements could be used to approximate force across the tissue. However, the techniques required are still being developed, and the greater Boston area currently lacks the equipment and expertise needed to attempt those experiments. 

    A big part of her work in the lab has been figuring out how to collect and analyze relevant data. This research has already taken her far and wide, both literally and virtually. 

    “We’ve found that people have been very generous with their time and expertise,” De La O says. “One of the benefits we, as fly people, brought into this field is we don’t know anything — so we’re going to question everything.”

    De La O traveled to the University of Virginia to learn live imaging techniques from associate professor of cell biology Ann Sutherland, and she’s also been in contact with Gabriel Galea at University College London, where Martin and De La O are considering a visit for further training. 

    “There are a lot of reasons why these experiments could go wrong, and one of them is that I’m not trained yet,” she says. “Once you know how to do things on an optimal setup, you can figure out how to make it work on a less-optimal setup.”

    Collaboration and community

    De La O has now expanded her cooking repertoire far beyond her family’s recipes and shares her new creations when she visits home. At MIT, she hosts dinner parties, including one where everything from the savory appetizers to the sweet desserts contained honey, thanks to an Independent Activities Period course about the producers of the sticky substance, and she made and tried apple pie for the first time with her fellow graduate students after an afternoon of apple picking. 

    De La O says she’s still learning how to say no to taking on additional work outside of her regular obligations as a PhD student; she’s found there’s a lot of pressure for underrepresented students to be at the forefront of diversity efforts, and although she finds that work extremely fulfilling, she can, and has, stretched herself too thin in the past. 

    “Every time I see an application that asks ‘How will you work to increase diversity,’ my strongest instinct is just to write ‘I’m brown and around — you’re welcome,’” she jokes. “The greatest amount of diversity work I will do is to get where I’m going. Me achieving my goals increases diversity inherently, but I also want to do well because I know if I do, I will make everything better for people coming after me.”

    De La O is confident her path will be in academia, and troubleshooting, building up protocols, and setting up standards for her work in the Martin Lab has been “an excellent part of my training program.” 

    De La O and Martin embarked on a new project in a new model for the lab for De La O’s thesis, so much of her graduate studies will be spent laying the groundwork for future research. 

    “I hope her travels open Juana’s eyes to science being a larger community and to teach her about how to lead a collaboration,” Martin says. “Overall, I think this project is excellent for a student with aspirations to be a PI. I benefited from extremely open-ended projects as a student and see, in retrospect, how they prepared me for my work today.” More

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    Celebrating five years of MIT.nano

    There is vast opportunity for nanoscale innovation to transform the world in positive ways — expressed MIT.nano Director Vladimir Bulović as he posed two questions to attendees at the start of the inaugural Nano Summit: “Where are we heading? And what is the next big thing we can develop?”

    “The answer to that puts into perspective our main purpose — and that is to change the world,” Bulović, the Fariborz Maseeh Professor of Emerging Technologies, told an audience of more than 325 in-person and 150 virtual participants gathered for an exploration of nano-related research at MIT and a celebration of MIT.nano’s fifth anniversary.

    Over a decade ago, MIT embarked on a massive project for the ultra-small — building an advanced facility to support research at the nanoscale. Construction of MIT.nano in the heart of MIT’s campus, a process compared to assembling a ship in a bottle, began in 2015, and the facility launched in October 2018.

    Fast forward five years: MIT.nano now contains nearly 170 tools and instruments serving more than 1,200 trained researchers. These individuals come from over 300 principal investigator labs, representing more than 50 MIT departments, labs, and centers. The facility also serves external users from industry, other academic institutions, and over 130 startup and multinational companies.

    A cross section of these faculty and researchers joined industry partners and MIT community members to kick off the first Nano Summit, which is expected to become an annual flagship event for MIT.nano and its industry consortium. Held on Oct. 24, the inaugural conference was co-hosted by the MIT Industrial Liaison Program.

    Six topical sessions highlighted recent developments in quantum science and engineering, materials, advanced electronics, energy, biology, and immersive data technology. The Nano Summit also featured startup ventures and an art exhibition.

    Watch the videos here.

    Seeing and manipulating at the nanoscale — and beyond

    “We need to develop new ways of building the next generation of materials,” said Frances Ross, the TDK Professor in Materials Science and Engineering (DMSE). “We need to use electron microscopy to help us understand not only what the structure is after it’s built, but how it came to be. I think the next few years in this piece of the nano realm are going to be really amazing.”

    Speakers in the session “The Next Materials Revolution,” chaired by MIT.nano co-director for Characterization.nano and associate professor in DMSE James LeBeau, highlighted areas in which cutting-edge microscopy provides insights into the behavior of functional materials at the nanoscale, from anti-ferroelectrics to thin-film photovoltaics and 2D materials. They shared images and videos collected using the instruments in MIT.nano’s characterization suites, which were specifically designed and constructed to minimize mechanical-vibrational and electro-magnetic interference.

    Later, in the “Biology and Human Health” session chaired by Boris Magasanik Professor of Biology Thomas Schwartz, biologists echoed the materials scientists, stressing the importance of the ultra-quiet, low-vibration environment in Characterization.nano to obtain high-resolution images of biological structures.

    “Why is MIT.nano important for us?” asked Schwartz. “An important element of biology is to understand the structure of biology macromolecules. We want to get to an atomic resolution of these structures. CryoEM (cryo-electron microscopy) is an excellent method for this. In order to enable the resolution revolution, we had to get these instruments to MIT. For that, MIT.nano was fantastic.”

    Seychelle Vos, the Robert A. Swanson (1969) Career Development Professor of Life Sciences, shared CryoEM images from her lab’s work, followed by biology Associate Professor Joey Davis who spoke about image processing. When asked about the next stage for CryoEM, Davis said he’s most excited about in-situ tomography, noting that there are new instruments being designed that will improve the current labor-intensive process.

    To chart the future of energy, chemistry associate professor Yogi Surendranath is also using MIT.nano to see what is happening at the nanoscale in his research to use renewable electricity to change carbon dioxide into fuel.

    “MIT.nano has played an immense role, not only in facilitating our ability to make nanostructures, but also to understand nanostructures through advanced imaging capabilities,” said Surendranath. “I see a lot of the future of MIT.nano around the question of how nanostructures evolve and change under the conditions that are relevant to their function. The tools at MIT.nano can help us sort that out.”

    Tech transfer and quantum computing

    The “Advanced Electronics” session chaired by Jesús del Alamo, the Donner Professor of Science in the Department of Electrical Engineering and Computer Science (EECS), brought together industry partners and MIT faculty for a panel discussion on the future of semiconductors and microelectronics. “Excellence in innovation is not enough, we also need to be excellent in transferring these to the marketplace,” said del Alamo. On this point, panelists spoke about strengthening the industry-university connection, as well as the importance of collaborative research environments and of access to advanced facilities, such as MIT.nano, for these environments to thrive.

    The session came on the heels of a startup exhibit in which eleven START.nano companies presented their technologies in health, energy, climate, and virtual reality, among other topics. START.nano, MIT.nano’s hard-tech accelerator, provides participants use of MIT.nano’s facilities at a discounted rate and access to MIT’s startup ecosystem. The program aims to ease hard-tech startups’ transition from the lab to the marketplace, surviving common “valleys of death” as they move from idea to prototype to scaling up.

    When asked about the state of quantum computing in the “Quantum Science and Engineering” session, physics professor Aram Harrow related his response to these startup challenges. “There are quite a few valleys to cross — there are the technical valleys, and then also the commercial valleys.” He spoke about scaling superconducting qubits and qubits made of suspended trapped ions, and the need for more scalable architectures, which we have the ingredients for, he said, but putting everything together is quite challenging.

    Throughout the session, William Oliver, professor of physics and the Henry Ellis Warren (1894) Professor of Electrical Engineering and Computer Science, asked the panelists how MIT.nano can address challenges in assembly and scalability in quantum science.

    “To harness the power of students to innovate, you really need to allow them to get their hands dirty, try new things, try all their crazy ideas, before this goes into a foundry-level process,” responded Kevin O’Brien, associate professor in EECS. “That’s what my group has been working on at MIT.nano, building these superconducting quantum processors using the state-of-the art fabrication techniques in MIT.nano.”

    Connecting the digital to the physical

    In his reflections on the semiconductor industry, Douglas Carlson, senior vice president for technology at MACOM, stressed connecting the digital world to real-world application. Later, in the “Immersive Data Technology” session, MIT.nano associate director Brian Anthony explained how, at the MIT.nano Immersion Lab, researchers are doing just that.

    “We think about and facilitate work that has the human immersed between hardware, data, and experience,” said Anthony, principal research scientist in mechanical engineering. He spoke about using the capabilities of the Immersion Lab to apply immersive technologies to different areas — health, sports, performance, manufacturing, and education, among others. Speakers in this session gave specific examples in hardware, pediatric health, and opera.

    Anthony connected this third pillar of MIT.nano to the fab and characterization facilities, highlighting how the Immersion Lab supports work conducted in other parts of the building. The Immersion Lab’s strength, he said, is taking novel work being developed inside MIT.nano and bringing it up to the human scale to think about applications and uses.

    Artworks that are scientifically inspired

    The Nano Summit closed with a reception at MIT.nano where guests could explore the facility and gaze through the cleanroom windows, where users were actively conducting research. Attendees were encouraged to visit an exhibition on MIT.nano’s first- and second-floor galleries featuring work by students from the MIT Program in Art, Culture, and Technology (ACT) who were invited to utilize MIT.nano’s tool sets and environments as inspiration for art.

    In his closing remarks, Bulović reflected on the community of people who keep MIT.nano running and who are using the tools to advance their research. “Today we are celebrating the facility and all the work that has been done over the last five years to bring it to where it is today. It is there to function not just as a space, but as an essential part of MIT’s mission in research, innovation, and education. I hope that all of us here today take away a deep appreciation and admiration for those who are leading the journey into the nano age.” More

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    Andrea Lo ’21 draws on ecological lessons for life, work, and education

    Growing up in Los Angeles about 10 minutes away from the Ballona Wetlands, Andrea Lo ’21 has long been interested in ecology. She witnessed, in real-time, the effects of urbanization and the impacts that development had on the wetlands. 

    “In hindsight, it really helped shape my need for a career — and a life — where I can help improve my community and the environment,” she says.

    Lo, who majored in biology at MIT, says a recurring theme in her life has been the pursuit of balance, valuing both extracurricular and curricular activities. She always felt an equal pull toward STEM and the humanities, toward wet lab work and field work, and toward doing research and helping her community. 

    “One of the most important things I learned in 7.30[J] (Fundamentals of Ecology) was that there are always going to be trade-offs. That’s just the way of life,” she says. “The biology major at MIT is really flexible. I got a lot of room to explore what I was interested in and get a good balance overall, with humanities classes along with technical classes.” 

    Lo was drawn to MIT because of the focus on hands-on work — but many of the activities Lo was hoping to do, both extracurricular and curricular, were cut short because of the pandemic, including her lab-based Undergraduate Research Opportunities Program (UROP) project. 

    Instead, she pursued a UROP with MIT Sea Grant, working on a project in partnership with Northeastern University and the Charles River Conservancy with funding support from the MIT Community Service fund as part of STEAM Saturday.  

    She was involved in creating Floating Wetland kits, an educational activity directed at students in grades 4 to 6 to help students understand ecological concepts,the challenges the Charles River faces due to urbanization, and how floating wetlands improve the ecosystem. 

    “Our hope was to educate future generations of local students in Cambridge in order for them to understand the ecology surrounding where they live,” she says. 

    In recent years, many bodies of water in Massachusetts have become unusable during the warmer months due to the process of eutrophication: stormwater runoff picks up everything — from fertilizer and silt to animal excrement — and deposits it at the lowest point, which is often a body of water. This leads to an excess of nutrients in the body of water and, when combined with warm temperatures, can lead to harmful algal blooms, making the water sludgy, bright green, and dangerously toxic. 

    The wetland kits Lo worked with were mini ecosystems, replicating a full-sized floating wetland. One such floating wetland can be seen from the Longfellow Bridge at one end of MIT’s campus — the Charles River floating wetland is a patch of grass attached to a buoy like a boat, which is often visited by birds and inhabited by much smaller critters that cannot be seen from the shore.  

    The Charles River floating wetland has a variety of flora, but the kits Lo helped present use only wheat grass because it is easy to grow and has long, dangling roots that could penetrate the watery medium below. A water tray beneath the grass — the Charles river of the mini ecosystem — contains spirulina powder for replicating algae growth and daphnia, which are small, planktonic crustaceans that help keep freshwater clean and usable. 

    “This work was really fulfilling, but it’s also really important, because environmental sustainability relies on future generations to carry on the work that past generations have been doing,” she says. “MIT’s motto is ‘mens et manus’ — education for practical application, and applying theoretical knowledge to what we do in our daily lives. I think this project really helped reinforce that.” 

    Since 2021, Lo has been working in Denmark in a position she learned about through the MIT-Denmark program. 

    She chose Denmark because of its reputation for environmental and sustainability issues and because she didn’t know much about it except for it being one of the happiest countries in the world, often thought of synonymously with the word “hygge,” which has no direct translation but encapsulates coziness and comfort from the small joys in life. 

    “At MIT, we have a very strong work-hard, play-hard culture. I think we can learn a lot from the work-life balance that Denmark has a reputation for,” she says. “I really wanted to take the opportunity in between graduation and whatever came after to explore beyond my bubble. For me, it was important to step back, out of my comfort zone, step into a different environment — and just live.”

    Currently, her personal project is comparing the conditions of two lagoons on the island of Fyn in Denmark. Both are naturally occurring, but in different states of environmental health. 

    She’s been doing a mix of field work and lab work. She collects sediment and fauna samples using a steel corer, or “butter stick” in her lab’s slang. In the same way that one can use a metal tube-shaped tool to remove the core of an apple, she punches the steel corer into the ground, removing a plug of sample. She then sifts the sample through 1 millimeter mesh, preserves the filtered sample in formalin, and takes everything back to the lab. 

    Once there, she looks through the sample to find macrofauna — mollusks, barnacles, and polychaetes, a bristly-looking segmented worm, for example. Collected over time, sediment characteristics like organic matter content, sediment grain size, and the size and abundance of macrofauna, can reveal trends that can help determine the health of the ecosystem. 

    Lo doesn’t have any concrete results yet, but her data could help researchers project the recovery of a lagoon that was rehabilitated using a technique called managed realignment, where water is allowed to reclaim areas where it was once found. She says she’s glad she gets a mix of field work and lab work, even on Denmark’s stormiest days. 

    “Sometimes there are really cold days where it’s windy and I wish I was in the lab, but, at the same time, it’s nice to have a balance where I can be outside and really be hands-on with my work,” she says.  

    Reflecting her dual interests in the technical and the innovative, she will be back in the Greater Boston area in the fall, pursuing a master of science in innovation and management and an MS in civil and environmental engineering at the Tufts Gordon Institute.

    “So much has happened and changed due to the pandemic that it’s easy to dwell on what could’ve been, but I tell myself to be optimistic and take the positive aspects that have come out of the circumstances,” Lo says. “My opportunities with the Sea Grant, MISTI, and Tufts definitely wouldn’t have happened if the pandemic hadn’t happened.” More

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    Exploring the links between diet and cancer

    Every three to five days, all of the cells lining the human intestine are replaced. That constant replenishment of cells helps the intestinal lining withstand the damage caused by food passing through the digestive tract.

    This rapid turnover of cells relies on intestinal stem cells, which give rise to all of the other types of cells found in the intestine. Recent research has shown that those stem cells are heavily influenced by diet, which can help keep them healthy or stimulate them to become cancerous.

    “Low-calorie diets such as fasting and caloric restriction can have antiaging effects and antitumor effects, and we want to understand why that is. On the other hand, diets that lead to obesity can promote diseases of aging, such as cancer,” says Omer Yilmaz, the Eisen and Chang Career Development Associate Professor of Biology at MIT.

    For the past decade, Yilmaz has been studying how different diets and environmental conditions affect intestinal stem cells, and how those factors can increase the risk of cancer and other diseases. This work could help researchers develop new ways to improve gastrointestinal health, either through dietary interventions or drugs that mimic the beneficial effects of certain diets, he says. 

    “Our findings have raised the possibility that fasting interventions, or small molecules that mimic the effects of fasting, might have a role in improving intestinal regeneration,” says Yilmaz, who is also a member of MIT’s Koch Institute for Integrative Cancer Research.

    A clinical approach

    Yilmaz’s interest in disease and medicine arose at an early age. His father practiced internal medicine, and Yilmaz spent a great deal of time at his father’s office after school, or tagging along at the hospital where his father saw patients.

    “I was very interested in medicines and how medicines were used to treat diseases,” Yilmaz recalls. “He’d ask me questions, and many times I wouldn’t know the answer, but he would encourage me to figure out the answers to his questions. That really stimulated my interest in biology and in wanting to become a doctor.”

    Knowing that he wanted to go into medicine, Yilmaz applied and was accepted to an eight-year, combined bachelor’s and MD program at the University of Michigan. As an undergraduate, this gave him the freedom to explore areas of interest without worrying about applying to medical school. While majoring in biochemistry and physics, he did undergraduate research in the field of protein folding.

    During his first year of medical school, Yilmaz realized that he missed doing research, so he decided to apply to the MD/PhD program at the University of Michigan. For his PhD research, he studied blood-forming stem cells and identified new markers that allowed such cells to be more easily isolated from the bone marrow.

    “This was important because there’s a lot of interest in understanding what makes a stem cell a stem cell, and how much of it is an internal program versus signals from the microenvironment,” Yilmaz says.

    After finishing his PhD and MD, he thought about going straight into research and skipping a medical residency, but ended up doing a residency in pathology at Massachusetts General Hospital. During that time, he decided to switch his research focus from blood-forming stem cells to stem cells found in the gastrointestinal tract.

    “The GI tract seemed very interesting because in contrast to the bone marrow, we knew very little about the identity of GI stem cells,” Yilmaz says. “I knew that once GI stem cells were identified, there’d be a lot of interesting questions about how they respond to diet and how they respond to other environmental stimuli.”

    Dietary questions

    To delve into those questions, Yilmaz did postdoctoral research at the Whitehead Institute, where he began investigating the connections between stem cells, metabolism, diet, and cancer.

    Because intestinal stem cells are so long-lived, they are more likely to accumulate genetic mutations that make them susceptible to becoming cancerous. At the Whitehead Institute, Yilmaz began studying how different diets might influence this vulnerability to cancer, a topic that he carried into his lab at MIT when he joined the faculty in 2014.

    One question his lab has been exploring is why low-calorie diets often have protective effects, including a boost in longevity — a phenomenon that has been seen in many studies in animals and humans.

    In a 2018 study, his lab found that a 24-hour fast dramatically improves stem cells’ ability to regenerate. This effect was seen in both young and aged mice, suggesting that even in old age, fasting or drugs that mimic the effects of fasting could have a beneficial effect.

    On the flip side, Yilmaz is also interested in why a high-fat diet appears to promote the development of cancer, especially colorectal cancer. In a 2016 study, he found that when mice consume a high-fat diet, it triggers a significant increase in the number of intestinal stem cells. Also, some non-stem-cell populations begin to resemble stem cells in their behavior. “The upshot of these changes is that both stem cells and non-stem-cells can give rise to tumors in a high-fat diet state,” Yilmaz says.

    To help with these studies, Yilmaz’s lab has developed a way to use mouse or human intestinal stem cells to generate miniature intestines or colons in cell culture. These “organoids” can then be exposed to different nutrients in a very controlled setting, allowing researchers to analyze how different diets affect the system.

    Recently, his lab adapted the system to allow them to expand their studies to include the role of immune cells, fibroblasts, and other supportive cells found in the microenvironment of stem cells. “It would be remiss of us to focus on just one cell type,” Yilmaz says. “We’re looking at how these different dietary interventions impact the entire stem cell neighborhood.”

    While Yilmaz spends most of his time running his lab at MIT, he also devotes six to eight weeks per year to his work at MGH, where he is an associate pathologist focusing on gastrointestinal pathology.

    “I enjoy my clinical work, and it always reminds me about the importance of the research we do,” he says. “Seeing colon cancer and other GI cancers under the microscope, and seeing their complexity, reminds me of the importance of our mission to figure out how we can prevent these cancers from forming.” More

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    Inaugural J-WAFS Grand Challenge aims to develop enhanced crop variants and move them from lab to land

    According to MIT’s charter, established in 1861, part of the Institute’s mission is to advance the “development and practical application of science in connection with arts, agriculture, manufactures, and commerce.” Today, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) is one of the driving forces behind water and food-related research on campus, much of which relates to agriculture. In 2022, J-WAFS established the Water and Food Grand Challenge Grant to inspire MIT researchers to work toward a water-secure and food-secure future for our changing planet. Not unlike MIT’s Climate Grand Challenges, the J-WAFS Grand Challenge seeks to leverage multiple areas of expertise, programs, and Institute resources. The initial call for statements of interests returned 23 letters from MIT researchers spanning 18 departments, labs, and centers. J-WAFS hosted workshops for the proposers to present and discuss their initial ideas. These were winnowed down to a smaller set of invited concept papers, followed by the final proposal stage. 

    Today, J-WAFS is delighted to report that the inaugural J-WAFS Grand Challenge Grant has been awarded to a team of researchers led by Professor Matt Shoulders and research scientist Robert Wilson of the Department of Chemistry. A panel of expert, external reviewers highly endorsed their proposal, which tackles a longstanding problem in crop biology — how to make photosynthesis more efficient. The team will receive $1.5 million over three years to facilitate a multistage research project that combines cutting-edge innovations in synthetic and computational biology. If successful, this project could create major benefits for agriculture and food systems worldwide.

    “Food systems are a major source of global greenhouse gas emissions, and they are also increasingly vulnerable to the impacts of climate change. That’s why when we talk about climate change, we have to talk about food systems, and vice versa,” says Maria T. Zuber, MIT’s vice president for research. “J-WAFS is central to MIT’s efforts to address the interlocking challenges of climate, water, and food. This new grant program aims to catalyze innovative projects that will have real and meaningful impacts on water and food. I congratulate Professor Shoulders and the rest of the research team on being the inaugural recipients of this grant.”

    Shoulders will work with Bryan Bryson, associate professor of biological engineering, as well as Bin Zhang, associate professor of chemistry, and Mary Gehring, a professor in the Department of Biology and the Whitehead Institute for Biomedical Research. Robert Wilson from the Shoulders lab will be coordinating the research effort. The team at MIT will work with outside collaborators Spencer Whitney, a professor from the Australian National University, and Ahmed Badran, an assistant professor at the Scripps Research Institute. A milestone-based collaboration will also take place with Stephen Long, a professor from the University of Illinois at Urbana-Champaign. The group consists of experts in continuous directed evolution, machine learning, molecular dynamics simulations, translational plant biochemistry, and field trials.

    “This project seeks to fundamentally improve the RuBisCO enzyme that plants use to convert carbon dioxide into the energy-rich molecules that constitute our food,” says J-WAFS Director John H. Lienhard V. “This difficult problem is a true grand challenge, calling for extensive resources. With J-WAFS’ support, this long-sought goal may finally be achieved through MIT’s leading-edge research,” he adds.

    RuBisCO: No, it’s not a new breakfast cereal; it just might be the key to an agricultural revolution

    A growing global population, the effects of climate change, and social and political conflicts like the war in Ukraine are all threatening food supplies, particularly grain crops. Current projections estimate that crop production must increase by at least 50 percent over the next 30 years to meet food demands. One key barrier to increased crop yields is a photosynthetic enzyme called Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase (RuBisCO). During photosynthesis, crops use energy gathered from light to draw carbon dioxide (CO2) from the atmosphere and transform it into sugars and cellulose for growth, a process known as carbon fixation. RuBisCO is essential for capturing the CO2 from the air to initiate conversion of CO2 into energy-rich molecules like glucose. This reaction occurs during the second stage of photosynthesis, also known as the Calvin cycle. Without RuBisCO, the chemical reactions that account for virtually all carbon acquisition in life could not occur.

    Unfortunately, RuBisCO has biochemical shortcomings. Notably, the enzyme acts slowly. Many other enzymes can process a thousand molecules per second, but RuBisCO in chloroplasts fixes less than six carbon dioxide molecules per second, often limiting the rate of plant photosynthesis. Another problem is that oxygen (O2) molecules and carbon dioxide molecules are relatively similar in shape and chemical properties, and RuBisCO is unable to fully discriminate between the two. The inadvertent fixation of oxygen by RuBisCO leads to energy and carbon loss. What’s more, at higher temperatures RuBisCO reacts even more frequently with oxygen, which will contribute to decreased photosynthetic efficiency in many staple crops as our climate warms.

    The scientific consensus is that genetic engineering and synthetic biology approaches could revolutionize photosynthesis and offer protection against crop losses. To date, crop RuBisCO engineering has been impaired by technological obstacles that have limited any success in significantly enhancing crop production. Excitingly, genetic engineering and synthetic biology tools are now at a point where they can be applied and tested with the aim of creating crops with new or improved biological pathways for producing more food for the growing population.

    An epic plan for fighting food insecurity

    The 2023 J-WAFS Grand Challenge project will use state-of-the-art, transformative protein engineering techniques drawn from biomedicine to improve the biochemistry of photosynthesis, specifically focusing on RuBisCO. Shoulders and his team are planning to build what they call the Enhanced Photosynthesis in Crops (EPiC) platform. The project will evolve and design better crop RuBisCO in the laboratory, followed by validation of the improved enzymes in plants, ultimately resulting in the deployment of enhanced RuBisCO in field trials to evaluate the impact on crop yield. 

    Several recent developments make high-throughput engineering of crop RuBisCO possible. RuBisCO requires a complex chaperone network for proper assembly and function in plants. Chaperones are like helpers that guide proteins during their maturation process, shielding them from aggregation while coordinating their correct assembly. Wilson and his collaborators previously unlocked the ability to recombinantly produce plant RuBisCO outside of plant chloroplasts by reconstructing this chaperone network in Escherichia coli (E. coli). Whitney has now established that the RuBisCO enzymes from a range of agriculturally relevant crops, including potato, carrot, strawberry, and tobacco, can also be expressed using this technology. Whitney and Wilson have further developed a range of RuBisCO-dependent E. coli screens that can identify improved RuBisCO from complex gene libraries. Moreover, Shoulders and his lab have developed sophisticated in vivo mutagenesis technologies that enable efficient continuous directed evolution campaigns. Continuous directed evolution refers to a protein engineering process that can accelerate the steps of natural evolution simultaneously in an uninterrupted cycle in the lab, allowing for rapid testing of protein sequences. While Shoulders and Badran both have prior experience with cutting-edge directed evolution platforms, this will be the first time directed evolution is applied to RuBisCO from plants.

    Artificial intelligence is changing the way enzyme engineering is undertaken by researchers. Principal investigators Zhang and Bryson will leverage modern computational methods to simulate the dynamics of RuBisCO structure and explore its evolutionary landscape. Specifically, Zhang will use molecular dynamics simulations to simulate and monitor the conformational dynamics of the atoms in a protein and its programmed environment over time. This approach will help the team evaluate the effect of mutations and new chemical functionalities on the properties of RuBisCO. Bryson will employ artificial intelligence and machine learning to search the RuBisCO activity landscape for optimal sequences. The computational and biological arms of the EPiC platform will work together to both validate and inform each other’s approaches to accelerate the overall engineering effort.

    Shoulders and the group will deploy their designed enzymes in tobacco plants to evaluate their effects on growth and yield relative to natural RuBisCO. Gehring, a plant biologist, will assist with screening improved RuBisCO variants using the tobacco variety Nicotiana benthamianaI, where transient expression can be deployed. Transient expression is a speedy approach to test whether novel engineered RuBisCO variants can be correctly synthesized in leaf chloroplasts. Variants that pass this quality-control checkpoint at MIT will be passed to the Whitney Lab at the Australian National University for stable transformation into Nicotiana tabacum (tobacco), enabling robust measurements of photosynthetic improvement. In a final step, Professor Long at the University of Illinois at Urbana-Champaign will perform field trials of the most promising variants.

    Even small improvements could have a big impact

    A common criticism of efforts to improve RuBisCO is that natural evolution has not already identified a better enzyme, possibly implying that none will be found. Traditional views have speculated a catalytic trade-off between RuBisCO’s specificity factor for CO2 / O2 versus its CO2 fixation efficiency, leading to the belief that specificity factor improvements might be offset by even slower carbon fixation or vice versa. This trade-off has been suggested to explain why natural evolution has been slow to achieve a better RuBisCO. But Shoulders and the team are convinced that the EPiC platform can unlock significant overall improvements to plant RuBisCO. This view is supported by the fact that Wilson and Whitney have previously used directed evolution to improve CO2 fixation efficiency by 50 percent in RuBisCO from cyanobacteria (the ancient progenitors of plant chloroplasts) while simultaneously increasing the specificity factor. 

    The EPiC researchers anticipate that their initial variants could yield 20 percent increases in RuBisCO’s specificity factor without impairing other aspects of catalysis. More sophisticated variants could lift RuBisCO out of its evolutionary trap and display attributes not currently observed in nature. “If we achieve anywhere close to such an improvement and it translates to crops, the results could help transform agriculture,” Shoulders says. “If our accomplishments are more modest, it will still recruit massive new investments to this essential field.”

    Successful engineering of RuBisCO would be a scientific feat of its own and ignite renewed enthusiasm for improving plant CO2 fixation. Combined with other advances in photosynthetic engineering, such as improved light usage, a new green revolution in agriculture could be achieved. Long-term impacts of the technology’s success will be measured in improvements to crop yield and grain availability, as well as resilience against yield losses under higher field temperatures. Moreover, improved land productivity together with policy initiatives would assist in reducing the environmental footprint of agriculture. With more “crop per drop,” reductions in water consumption from agriculture would be a major boost to sustainable farming practices.

    “Our collaborative team of biochemists and synthetic biologists, computational biologists, and chemists is deeply integrated with plant biologists and field trial experts, yielding a robust feedback loop for enzyme engineering,” Shoulders adds. “Together, this team will be able to make a concerted effort using the most modern, state-of-the-art techniques to engineer crop RuBisCO with an eye to helping make meaningful gains in securing a stable crop supply, hopefully with accompanying improvements in both food and water security.” More

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    Recycling plastics from research labs

    In 2019, MIT’s Environment, Health, and Safety (EHS) Office collaborated with several research labs in the Department of Biology to determine the feasibility of recycling clean lab plastics. Based on early successes with waste isolation and plastics collection, EHS collaborated with GreenLabs Recycling, a local startup, to remove and recycle lab plastics from campus. It was a huge success.

    Today, EHS spearheads the campus Lab Plastics Recycling Program, and its EHS technicians regularly gather clean lab plastics from 212 MIT labs, transferring them to GreenLabs for recycling. Since its pilot stage, the number of labs participating in the program has grown, increasing the total amount of plastic gathered and recycled. In 2020, EHS collected 170 pounds of plastic waste per week from participating labs. That increased to 250 pounds per week in 2021. In 2022, EHS collected a total of 19,000 pounds, or 280 pounds of plastic per week.

    Joanna Buchthal, a research assistant with the MIT Media Lab, indicates that, prior to joining the EHS Lab Plastics Recycling Program, “our laboratory was continuously troubled by the substantial volume of plastic waste we produced and disheartened by our inability to recycle it. We frequently addressed this issue during our group meetings and explored various ways to repurpose our waste, yet we never arrived at a viable solution.”

    The EHS program now provides a solution to labs facing similar challenges with plastics use. After pickup and removal, the plastics are shredded and sold as free stock for injection mold product manufacturing. Buchthal says, “My entire lab is delighted to recycle our used tip boxes and transform them into useful items for other labs!”

    Recently, GreenLabs presented EHS with a three-gallon bucket that local manufacturers produced from 100 percent recycled plastic gathered from MIT labs. No fillers or additives were used in its production.

    Keeping it clean

    The now-growing EHS service and operation started as a pilot. In June 2019, MIT restricted which lab-generated items could be placed in single-stream recycling. MIT’s waste vendors were no longer accepting possibly contaminated waste, such as gloves, pipette tip boxes, bottles, and other plastic waste typically generated in biological research labs. The waste vendors would audit MIT’s single-stream recycling and reject items if they observed any contamination.

    Facing these challenges, the EHS coordinator for biology, John Fucillo, and several EHS representatives from the department met with EHS staff to brainstorm potential recycling solutions. Ensuring the decontamination of the plastic and coordinating its removal in an efficient way were the primary challenges for the labs, says Fucillo, who shared his and lab members’ concerns about the amount of plastic being thrown away with Mitch Galanek, EHS associate director for the Radiation Protection Program. Galanek says, “I immediately recognized the frustration expressed by John and other lab contacts as an opportunity to collaborate.”

    In July 2019, Galanek and a team of EHS technicians began segregating and collecting clean plastic waste from several labs within the biology department. EHS provided the labs with collection containers, and its technicians managed the waste removal over a four-month period, which produced a snapshot of the volume and type of waste generated. An audit of the waste determined that approximately 80 percent of the clean plastic waste generated was empty pipette tip boxes and conical tube racks.

    Based on these data, EHS launched a lab plastics recycling pilot program in November 2019. Labs from the Department of Biology and the Koch Institute for Integrative Cancer Research were invited to participate by recycling their clean, uncontaminated pipette tip boxes and conical tube racks. In addition to providing these labs with collection boxes and plastic liners, EHS also developed an online waste collection request tool to submit plastic pickup requests. EHS also collected the waste containers once they were full.

    Assistant professor of biology Seychelle Vos joined the pilot program as soon as she started her lab in fall 2019. Vos shares that “we already use pipette tips boxes that produce minimal waste, and this program allows us to basically recycle any part of the box except for tips. Pipette boxes are a significant source of plastic waste. This program helps us to be more environmentally and climate friendly.” 

    Given the increased participation in the program, EHS technician Dave Pavone says that plastic pickup is now a “regular component of our work schedules.”

    Together, the EHS technicians, commonly known as “techs,” manage the pickup of nearly 300 plastic collection containers across campus. Normand Desrochers, one of the EHS techs, shares that each morning he plans his pickup route “to get the job done efficiently.” While weekly pickups are a growing part of their schedules, Desrochers notes that everyone has been “super appreciative in what we do for their labs. And what we do makes their job that much easier, being able to focus on their research.”

    Barbara Karampalas, a lab operations manager within the Department of Biological Engineering, is one of many to express appreciation for the program: “We have a fairly large lab with 35 researchers, so we generate a lot of plastic waste … [and] knowing how many tip boxes we were using concerned me. I really appreciate the effort EHS has made to implement this program to help us reduce our impact on the environment.” The program also “makes people in the lab more aware of the issue of plastic waste and MIT’s commitment to reduce its impact on the environment,” says Karampalas.

    Looking ahead

    MIT labs continue to enthusiastically embrace the EHS Lab Plastics Recycling Program: 112 faculty across 212 labs are currently participating in the program. While only empty pipette tip boxes and conical tube racks are currently collected, EHS is exploring which lab plastics could be manufactured into products for use in the labs and repeatedly recycled. Specifically, the EHS Office is considering whether recycled plastic could be used to produce secondary containers for collecting hazardous waste and benchtop transfer containers used for collecting medical waste. As Seychelle notes, “Most plastics cannot be recycled in the current schemes due to their use in laboratory science.”

    Says Fucillo, “Our hope is that this program can be expanded to include other products which could be recycled from the wet labs.” John MacFarlane, research engineer and EHS coordinator for civil and environmental engineering, echoes this sentiment: “With plastic recycling facing economic constraints, this effort by the Institute deserves to be promoted and, hopefully, expanded.”

    “Having more opportunities to recycle ’biologically clean’ plastics would help us have a smaller carbon footprint,” agrees Vos. “We love this program and hope it expands further!”

    MIT labs interested in participating in the EHS Lab Plastics Recycling Program can contact pipetip@mit.edu to learn more. More

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    Scientists uncover the amazing way sandgrouse hold water in their feathers

    Many birds’ feathers are remarkably efficient at shedding water — so much so that “like water off a duck’s back” is a common expression. Much more unusual are the belly feathers of the sandgrouse, especially Namaqua sandgrouse, which absorb and retain water so efficiently the male birds can fly more than 20 kilometers from a distant watering hole back to the nest and still retain enough water in their feathers for the chicks to drink and sustain themselves in the searing deserts of Namibia, Botswana, and South Africa.

    How do those feathers work? While scientists had inferred a rough picture, it took the latest tools of microscopy, and patient work with a collection of sandgrouse feathers, to unlock the unique structural details that enable the feathers to hold water. The findings appear today in the Journal of the Royal Society Interface, in a paper by Lorna Gibson, the Matoula S. Salapatas Professor of Materials Science and Engineering and a professor of mechanical engineering at MIT, and Professor Jochen Mueller of Johns Hopkins University.

    The unique water-carrying ability of sandgrouse feathers was first reported back in 1896, Gibson says, by E.G.B. Meade-Waldo, who was breeding the birds in captivity. “He saw them behaving like this, and nobody believed him! I mean, it just sounded so outlandish,” Gibson says.

    In 1967, Tom Cade and Gordon MacLean reported detailed observations of the birds at watering holes, in a study that proved the unique behavior was indeed real. The scientists found that male sandgrouse feathers could hold about 25 milliliters of water, or about a tenth of a cup, after the bird had spent about five minutes dipping in the water and fluffing its feathers.

    About half of that amount can evaporate during the male bird’s half-hour-long flight back to the nest, where the chicks, which cannot fly for about their first month, drink the remainder straight from the feathers.

    Cade and MacLean “had part of the story,” Gibson says, but the tools didn’t exist at the time to carry out the detailed imaging of the feather structures that the new study was able to do.

    Gibson and Mueller carried out their study using scanning electron microscopy, micro-computed tomography, and video imaging. They borrowed Namaqua sandgrouse belly feathers from Harvard University’s Museum of Comparative Zoology, which has a collection of specimens of about 80 percent of the world’s birds.

    Bird feathers in general have a central shaft, from which smaller barbs extend, and then smaller barbules extend out from those. Sandgrouse feathers are structured differently, however. In the inner zone of the feather, the barbules have a helically coiled structure close to their base and then a straight extension. In the outer zone of the feather, the barbules lack the helical coil and are simply straight. Both parts lack the grooves and hooks that hold the vane of contour feathers together in most other birds.
    Video of water spreading through the specialized sandgrouse feathers, under magnification, shows the uncoiling and spreading of the feather’s barbules as they become wet. Initially, most barbules in the outer zone of the feather form tubular features.Credit: Specimen #142928, Museum of Comparative Zoology, Harvard University © President and Fellows of Harvard College.

    When wetted, the coiled portions of the barbules unwind and rotate to be perpendicular to the vane, producing a dense forest of fibers that can hold water through capillary action. At the same time, the barbules in the outer zone curl inward, helping to hold the water in.

    The microscopy techniques used in the new study allowed the dimensions of the different parts of the feather to be measured. In the inner zone, the barb shafts are large and stiff enough to provide a rigid base about which the other parts of the feather deform, and the barbules are small and flexible enough that surface tension is sufficient to bend the straight extensions into tear-like structures that hold water. And in the outer zone, the barb shafts and barbules are smaller still, allowing them to curl around the inner zone, further retaining water.

    While previous work had suggested that surface tension produced the water retention characteristics, “what we did was make measurements of the dimensions and do some calculations to show that that’s what is actually happening,” Gibson says. Her group’s work demonstrated that the varying stiffnesses of the different feather parts plays a key role in their ability to hold water.

    The study was mostly driven by intellectual curiosity about this unique behavioral phenomenon, Gibson says. “We just wanted to see how it works. The whole story just seemed so interesting.” But she says it might lead to some useful applications. For example, in desert regions where water is scarce but fog and dew regularly occur, such as in Chile’s Atacama Desert, some adaptation of this feather structure might be incorporated into the systems of huge nets that are used to collect water. “You could imagine this could be a way to improve those systems,” she says. “A material with this kind of structure might be more effective at fog harvesting and holding the water.”

    “This fascinating and in-depth study reveals how the different parts of the sandgrouse’s belly feathers — including the microscopic barb shafts and barbules — work together to hold water,” says Mary Caswell Stoddard, an evolutionary biologist at Princeton University, who was not associated with this study. “By using a suite of advanced imaging techniques to describe the belly feathers and estimate their bending stiffnesses, Mueller and Gibson add rich new details to our understanding of the sandgrouse’s water-carrying feathers. … This study may inspire others to take a closer look at diverse feather microstructures across bird species — and to wonder whether these structures, as in sandgrouse, help support unusual or surprising functions.”

    The work was partly supported by the National Science Foundation and the Matoula S. Salapatas Professorship in Materials Science and Engineering at MIT. More