UCR Study Develops Genetic Database to Analyze Oil Toxicity in Fish

Daniel Schlenk is a professor of aquatic ecotoxicology in the Department of Environmental Sciences

The impacts of the Deepwater Horizon oil spill on the development of fish embryos and larvae have been documented for several species, including the economically and ecologically important mahi-mahi. Until now, scientists have struggled to understand how exposure to toxic compounds in oil changes gene expression. That’s because very limited molecular data exists for the species.

To change this, UCR researchers have developed the first transcriptomic database (a record of the RNA molecules that are transcribed from DNA) for mahi-mahi embryos and larvae exposed to oil from the Deepwater Horizon incident. The team assembled over 60,000 transcripts, identified over 30,000 gene sequences, and observed 2,345 genes that differed significantly after exposure to weathered oil.

“The molecular mechanisms for developmental toxicity of Deepwater Horizon oil mixture in wild fish are complex,” explained Daniel Schlenk, a professor of aquatic ecotoxicology in the Department of Environmental Sciences who led the research. “If we can identify the specific targets for oil and susceptible life stages in animals, we can better evaluate the risks of oil on animal health and focus field assessments and recovery efforts when potential spills occur.”

The researchers described their findings in a Scientific Reports article titled “Novel Transcriptome Assembly and Comparative Toxicity Pathway Analysis in Mahi-Mahi (Coryphaena hippurus) Embryos and Larvae Exposed to Deepwater Horizon Oil.” The first author is Elvis Genbo Xu, a postdoctoral fellow in Schlenk’s lab.

-Sarah Nightingale

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