URI student spends summer studying disease tolerance among oysters

Johnston resident considering career in scientific research

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URI student Rachael Renzi poses in a laboratory while conducting studies of disease tolerance in oysters. (Photo by Nora Lewis.)

KINGSTON, R.I. – August 11, 2016 – When University of Rhode Island junior Rachael Renzi enrolled in an advanced placement biology class in high school, she became fascinated by the subject and was especially enamored of the laboratory studies.

The Johnston resident renewed her enthusiasm for biology labs this summer as one of 100 college students from throughout the state selected as Summer Undergraduate Research Fellows. Renzi, a biological sciences major, spent the last 10 weeks conducting laboratory studies of disease tolerance among oysters, a project that she and her mentors hope will benefit Rhode Island’s thriving oyster aquaculture industry.

“We’re trying to see if there is any variation in disease tolerance within selectively-bred families of oysters,” Renzi said. “We wanted to see if there was a genetic difference in their ability to tolerate disease.”

Working in collaboration with URI postdoctoral researcher Tal Ben-Horin and U.S. Department of Agriculture scientist Dina Proestou, Renzi injected oysters with various concentrations of the parasite that causes Dermo, a common oyster pathogen, and collected oyster tissue samples from some of them at different points in time. She then extracted DNA from them, as well as from those that died, to determine the concentration of parasites each contained and to characterize how the disease proliferated through time.

“That told us how much they were able to withstand, how much they can absorb and still survive, and how much it takes to kill them,” she explained.

While the experiment is not yet finished, Renzi said that the data collected 29 days after injecting the oysters with the parasite indicates that one family of oysters had a much higher death rate than other families, despite receiving the same parasite dosage.

“But oysters have to live a couple of years before they’re ready for market, so we’ll have to wait for the later results before we know their true tolerance,” she said.

Her research has important implications. Dermo, originally found in southern locations, has spread northward as climate change has increased water temperatures, ramping up the threat to oyster production. The expectation is that Dermo will spread and grow more severe as water temperatures rise along the New England coast.

Funding for Renzi’s research fellowship was provided by the Experimental Program to Stimulate Competitive Research (EPSCoR) program of the National Science Foundation, which has provided more than $26 million in grants to support scientific research in Rhode Island. She presented the results of her research at a conference at URI on July 29.

Renzi, who had previous experience interning in a medical diagnostics lab, said the fellowship provided her with great insight into the process of scientific research, which is one career path she is considering.

“It was great to work as part of a team and see how research actually gets done,” she said. “The hands-on work was the part of the program I found most appealing. I liked how every day was different, how you don’t really know what you’re going to get into until you’re in the middle of it. Processing data, reading results, and seeing how it all comes together was really cool to see.”