University of North Carolina at Chapel Hill researchers [Duronio Lab] have determined whether a specific chemical modification of a protein that packages the genome called a histone affects gene activity and cell proliferation according to the paper, “Drosophila melanogaster Set8 and L(3)mbt function in gene expression independently of histone H4 lysine 20 methylation,” published in Genes & Development.

In their research, the group found that removing the enzymes responsible for adding a specific histone chemical modification or a protein that binds it disrupts gene activity and cell proliferation. However, the disruptions are not directly due to the chemical modification itself which is the opposite of current models in the field.

“Our study led to a better understanding of genetic regulation mechanisms,” said Bob Duronio, co-author and biology professor. “Such understanding provides foundational information that can help when developing new treatments for diseases like cancer that result from defects in the regulation of gene activity and cell proliferation by targeting the pathways and mechanisms of Set8 that are independent of the histone modification.” READ MORE

Alexander Smith (Allen Hurlbert Lab) used his Summer Undergraduate Research Fellowship to explore how the bugs’ cyclical emergence changed some animals’ feeding habits around the Triangle.

The emergence of millions of cicadas across North Carolina caused a buzz in parts of Chapel Hill and the Triangle this spring as Brood XIX surfaced for the first time in 13 years.

For Alexander Smith, the arrival of the periodical cicadas around Carolina’s campus also presented an opportunity for research.

Smith, a senior biology major, was curious how this year’s addition of millions of bugs would impact the food web dynamics of insects and their predators, including birds, reptiles, arachnids and small mammals.

“When periodical cicadas are introduced into an ecosystem and into a food web, it’s going to alter that food web,” said Smith, who received a Summer Undergraduate Research Fellowship (SURF) grant from the Office for Undergraduate Research to support his work.

A passion for the outdoors

Smith works in the laboratory of biology professor Allen Hurlbert, his SURF advisor. The laboratory experience and community have been central to Smith’s past year at Carolina.

Smith, 28, describes himself as a non-traditional student. After graduating high school, he served in the Army before pursuing the first years of his college career at Cleveland Community College. He transferred to Carolina knowing he wanted to pursue a career related to his love for animals and the outdoors, which he has had since childhood.

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We are pleased to announce that Derek Cain has started as the new Associate Chair for Business Administration in the Department of Biology, effective Monday, July 8, 2024.

Derek earned a Master’s of Business Administration in Health Care Management from East Carolina University and a Bachelor’s of Science in Information Systems from UNC Greensboro. He joins us from UNC Health where he served in roles such as a Regional Administrator and, most recently, as the System Equity and Inclusion Manager. He brings a wealth of knowledge and experience in creating and sustaining processes to improve efficiency while maintaining positive relationships with the people connected to those systems. Interesting fact – Derek is a chapter liaison and volunteer for the Food Bank of Central and Eastern North Carolina, as well as an active member of Alpha Phi Alpha Fraternity, Inc.

Mechanical and biochemical feedback combine to generate complex contractile oscillations in cytokinesis https://doi.org/10.1016/j.cub.2024.06.037

The actomyosin cortex is an active material that generates force to drive shape changes via cytoskeletal remodeling. Cytokinesis is the essential cell division event during which a cortical actomyosin ring closes to separate two daughter cells. Our active gel theory predicted that actomyosin systems controlled by a biochemical oscillator and experiencing mechanical strain would exhibit complex spatiotemporal behavior. To test whether active materials in vivo exhibit spatiotemporally complex kinetics, we imaged the C. elegans embryo with unprecedented temporal resolution and discovered that sections of the cytokinetic cortex undergo periodic phases of acceleration and deceleration. Contractile oscillations exhibited a range of periodicities, including those much longer periods than the timescale of RhoA pulses, which was shorter in cytokinesis than in any other biological context. Modifying mechanical feedback in vivo or in silico revealed that the period of contractile oscillation is prolonged as a function of the intensity of mechanical feedback. Fast local ring ingression occurs where speed oscillations have long periods, likely due to increased local stresses and, therefore, mechanical feedback. Fast ingression also occurs where material turnover is high, in vivo and in silico. We propose that downstream of initiation by pulsed RhoA activity, mechanical feedback, including but not limited to material advection, extends the timescale of contractility beyond that of biochemical input and, therefore, makes it robust to fluctuations in activation. Circumferential propagation of contractility likely allows for sustained contractility despite cytoskeletal remodeling necessary to recover from compaction. Thus, like biochemical feedback, mechanical feedback affords active materials responsiveness and robustness.

From The Daily Tar Heel: UNC academics research shark ecology and mislabeling of shark meat in grocery stores

“…At UNC, sharks take the limelight for longer than a week, with many professors and students researching and studying the creatures year-round.

Joel Fodrie, a professor and the director of the Institute of Marine Sciences, leads a lab group that is broadly focused on estuarine ecology and how different organisms interact with one another within the larger coastal community, one of them being sharks. The lab is also the primary caretaker of the UNC-IMS longline shark survey, the oldest of its kind in the United States.

The survey helps gauge shark behaviors over the course of decades, Fodrie said. It aids with longer-term understanding, something that is vital in fully comprehending the behavior and nature of sharks from many species.

Fodrie said that North Carolina’s coastline, estuarine systems, temperature changes and abundance of seagrass all provide for a prime environment that can support over 50 species of sharks, with around 20 that can be caught with some regularity.

Over the past three years, Fodrie’s lab has been looking into the trophic ecology of sharks, dealing with what sharks eat. By studying the subject, the lab is able to gauge what conditions are conducive to a proper habitat for various shark species.

Studying trophic ecology has been vital in deducting larger patterns of migration and interaction for sharks within a larger ecosystem, along with understanding where they fit into a larger food web.

John Bruno, a professor in the Department of Biology, primarily researches marine biodiversity, macroecology, coral reef ecology and conservation and climate change’s impact on marine ecosystems.

Bruno teaches Biology 221: Seafood Forensics, a course-based undergraduate research experience typically offered in the fall, providing students the opportunity to conduct research on topics of their choosing.

“It’s so much fun to teach these classes too,” Bruno said. “It’s way more rewarding than just teaching a lecture course because you make a lot of connections with the student. You really get to know them.”

Bruno said that a group of four students came up with an idea to study the mislabeling of shark meat at grocery stores, and conducted the research themselves in fall of 2022. After the project’s success, Bruno’s next fall section in 2023 repeated the experiment, but with a greater sample size with previous students serving as Undergraduate Learning Assistants.

Bruno’s class found that within the 30 samples they collected, 97 percent were mislabeled. 70 percent were labeled as shark but not to species, and of the nine that were named to species, eight were mislabeled. Out of all 30, one sample was correctly labeled…”

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Upon first glance, the fourth floor of Wilson Hall on UNC-Chapel Hill’s campus is no different from the rest of the biology department building: fluorescent lighting, white tile floors, ancient wooden desks in professors’ offices.

But then Patricia Gensel leads me to a door at the end of the hallway. She buzzes with excitement as she slides the key into the lock. After a particularly satisfying “click,” the door opens — and her world unfolds. Floor-to-ceiling drawers filled with specimens. Rolling carts covered in rocks. And on a table in the center, a giant slab that most people can’t get their arms around.

“I don’t go in for small,” Gensel says with a laugh. “At one point I had about 4,000 specimens, but I donated a lot to museums in the U.S. and Canada. Now, I’d guess I have closer to 2,000.”

She directs my attention back to the giant rock. Upon closer inspection, an outline of what looks like some type of fern is embedded in its top.

“This is foliage. An early seed plant, most likely,” she says.

Gensel is a paleobotanist. She studies plants from the Devonian and Lower Carboniferous periods, which date back 327-400 million years — pre-dating dinosaurs. This timeframe marks the beginning of plants that lived on land, produced seeds, grew root systems, and developed wood, ultimately forming into trees.

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Dr. Parul Johri has received the prestigious Early-Career Excellence Award from the Society for Molecular Biology and Evolution. This award is intended for outstanding members of the SMBE community who are in the early stages of an independent research career (3-7 years post-Ph.D.). The primary signal of research excellence is a trajectory of innovative, creative research that is moving the field of Molecular Biology and Evolution forward.

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Many bird species commonly aggregate in flocks for reasons ranging from predator defense to navigation. Available evidence suggests that certain types of flocks—the V and echelon formations of large birds—may provide a benefit that reduces the aerodynamic cost of flight, whereas cluster flocks typical of smaller birds may increase flight costs. However, metabolic flight costs have not been directly measured in any of these group flight contexts [Zhang and Lauder, J. Exp. Biol. 226, jeb245617 (2023)]. Here, we measured the energetic benefits of flight in small groups of two or three birds and the requirements for realizing those benefits, using metabolic energy expenditure and flight position measurements from European Starlings flying in a wind tunnel.

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Salomé Jaramillo Gil’s research journey began during her undergraduate studies in Colombia, where she studied the habitat preferences of the yellow stingray in the Caribbean. Then, she moved to Mexico, where she pursued a master’s degree in marine ecology, affording her the opportunity to study whale sharks’ movements in the Gulf of California. Now, as a Fulbright scholar, she is embarking on her PhD in biology at UNC-Chapel Hill under the mentorship of biology professor John Bruno. Her doctoral research is taking her to the Galápagos Islands, where she is focusing on the behavior and ecology — the relationship between an organism and its environment — of hammerhead sharks and eagle rays.

We asked Salomé about her research and experience in the archipelago. READ MORE

That’s a Cap!

Undergraduate researchers from Carolina’s 2024 graduating class share how research has shaped their college experience.