Biology in Action

L: Magnified view of embryonic sea anemones (Nematostella vectensis) from the lab of Katerina Ragkousi, assistant professor of biology. The normally colorless anemones are marked with a green fluorescent protein to track the dynamic behavior of a protein called actin. Actin has many important jobs in a cell, including establishing the cell’s shape. 

R:  SURF researcher Jin Jeon ’22 sits at the microinjection station where she painstakingly inserted tiny rings of DNA into sea anemone embryos. Jeon’s work will contribute to a Ragkousi lab publication on the role of the cytoskeleton during embryonic development.

If the tiny glass pipette slipped even a little, it could spell disaster for the sensitive embryo. It required a very steady hand—and weeks of advanced training and practice—for Jin Jeon ’22 to learn how to use the microinjection station that would alter the developing sea anemones. For most of the summer, Jeon’s research tasks in Professor Katerina Ragkousi’s molecular biology lab were invisible to the eye. It took an agonizing eight weeks to finish constructing the plasmids, or tiny rings of DNA, in host bacteria. Then came the tricky work of introducing the plasmids into the sea anemone embryos, each smaller than the head of a pin. 

In nature, few sea anemone eggs survive to maturity. In the lab, Jeon knew that only one in five would make it through the microinjection procedure, and only some of those would successfully get fertilized and start to grow. “There was a time when I thought, ‘Oh, this is probably never gonna happen,’” says Jeon. “I struggled a lot.”

Finally, in the waning weeks of summer, Jeon reached her project goals and claimed her reward: a chance to use a confocal microscope to observe in real time how the injected embryos were developing. “That was extremely satisfying,” says Jeon. She credits both Professor Ragkousi and the lab’s research specialist, Alivia Price, with giving her the biggest gift of the SURF summer experience: “Perseverance!”

L: Black bear hair left behind on a ring of elevated barbed wire. A scented lure draws bears to brush against the wires, leaving behind hair samples. Biology Laboratory Coordinator Thea Kristensen and her students extract DNA from the skin follicles attached to the hair, and then genotype the DNA to determine which bear is which and to match samples across locations and time. Data from the study will help inform state policies on bear management.

R: SURF researcher Eleanor Hollers ’21 collects hair samples from one of the 122 bear hair corrals set up across the state this summer as part of the MassBears project, which is estimating the population size and distribution of black bears in Massachusetts. The project is led by Kristensen, in collaboration with Kathy Zeller and Steve DeStefano from UMass Amherst and Dave Wattles from MassWildlife.

If you live in Massachusetts, you know this already: The bears are coming back.

“In the mid-1800s, bears were pretty much extirpated from Massachusetts by hunting and deforestation,” says Eleanor Hollers ’21. Now, more than 150 years later, hunting is regulated, and pockets of dense forest have returned, restoring the bears’ habitat. In areas just beyond cities and suburbs, bear populations can thrive thanks to humans’ garbage cans and backyard bird feeders.

Thea Kristensen, biology laboratory coordinator, leads the team of students who are helping conduct the state’s first bear population study since 1993. In collaboration with MassWildlife, the Massachusetts Cooperative Fish and Wildlife Research Unit and UMass Amherst, Kristensen and her team are estimating the population size of the state’s black bears and determining how they are distributed east and west of the Connecticut River.

To do this, they used a noninvasive survey technique: hair corrals. A hair corral consists of two parallel strands of barbed wire wrapped low around a small circle of trees. At the center of each circle, researchers suspended a lure doused with various liquid scents appealing to bears. (Judie’s Restaurant in Amherst donated cooking oil for this purpose.) As the bears passed through the wires to investigate, they left behind more than 1,870 hair samples for Kristensen’s team to collect for lab analysis.

Aspiring veterinarian Hollers relished the research assignment that gave her ample time outdoors—plus one actual bear encounter. “I’m a crazy animal lover,” she says. “If vet school doesn’t work out, scientific fieldwork would be a good alternative.”