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On the academic track
December 3, 2014
The research team is studying cardiovascular toxicity as larvae develop in the presence of potentially harmful compounds.
The below story was written by Steven Powell and is reprinted here from UofSC Today.
Gopher tortoises, snakes and a variety of other critters were some of Jessica Leet’s childhood companions. They roamed her yard and the wooded neighborhood where she grew up in central Florida.
Having a chance to see wildlife up close and personal in her formative years is one reason she decided to pursue environmental science in college, but it may have been a Barbie doll that sparked her interest as much as anything else.
“My mom was a fourth-grade teacher, and every year for Earth Day her class would bury trash at their school and then dig it up the next year to see how it degraded over time,” Leet says. “She did that for 15 years, and they have a Barbie doll that still looks exactly the same as the day they buried it, except for the fact that it’s a little dirty.”
Leet has carried that interest in how humans impact nature into a scientific career that has evolved over her undergraduate, graduate and postgraduate studies. After earning a bachelor’s degree in environmental science at the University of Central Florida, Leet studied toxicology for her master’s at the University of Tennessee at Chattanooga and doctoral work at Purdue.
She began by researching how synthetic compounds released into the environment affect wildlife, but in her postdoctoral work here at the University of South Carolina, her focus shifted to human toxicology.
In a sense, she’s following the life cycle of man-made compounds as they come full circle, returning to bite the hand that created them. From pesticides to health-care products to pharmaceuticals, lots of chemicals are very persistent in the environment, Leet says, sometimes passing through wastewater treatment facilities unchanged.
“There’s a huge number of chemicals that industry is producing every day, things that are potentially getting into the environment,” she says. “There’s so much we don’t know and so much potential for learning.”
Working in Dave Volz’s lab in the Arnold School of Public Health, Leet is doing her part to help close the knowledge gap. In one project, the lab uses zebrafish as a high-throughput alternative to traditional toxicology methods.
“Rodent models are very labor-intensive and expensive, so there’s only so much screening you can do,” Leet says. “But zebrafish are very easy to rear, the husbandry is pretty well established, they’re very hardy organisms and easy to keep in the lab, and they spawn hundreds of eggs at a time, which is great for getting a huge sample size.”
Because the fish are spawned and grow externally in transparent eggs, they’re a perfect tool for developmental toxicology; that is, following the effects of a chemical on early life stages. In contrast to traditional tests that determine how much of a substance is needed to be lethal to an organism, the genetically modified zebrafish that the team is using allow more subtle effects to be studied.
“We use fluorescent imaging for our fish,” Leet says. “It basically lights up the vasculature so we can analyze morphological as well as the functional endpoint of heart rate to assess cardiovascular toxicity.”
Much as she loves the lab, Leet has ventured beyond it this semester by teaching an introductory biology class at Carolina’s Aiken campus. She hopes to combine teaching and research in an academic position after completing her postdoctoral work. Her efforts in trying to navigate that career path have been helped quite a bit, she says, by the USC Postdoctoral Association.
The association is only about a year old, but with the support of Prakash Nagarkatti, vice president for research, the group has been able to get funding for events that help postdocs better navigate the sometimes difficult transition between graduate school and permanent employment. Now serving as the association’s vice president, Leet has helped organize a series of professional development seminars this semester.
“We had a panel discussion as one of our events, with speakers talking about their first year as academic faculty,” she says. “They gave a lot of really good insight into how to manage everything, how to negotiate for a job — all of the things that may be difficult to gain inside information on but are part of the process.
“We have also been posting all of our career development events on YouTube, so even if people can’t make it to the actual event, they can watch the videos on their own time.”
