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Cavefish development and evolution: A research review from two Stowers Graduate School Predoctoral Researchers

Amruta Swaminathan and Fanning Xia, Stowers Graduate School predoctoral researchers published a scientific review article on cavefish research.

08 November 2023

Amruta Swaminathan and Fanning Xia in the cavefish facility at the Stowers Institute.

The Mexican tetra fish, Astyanax mexicanus, is a powerful system to study genetics underpinning evolution and adaptation. These fish that populate both rivers and underground caves in Central America have the potential to unlock insights for treating human diseases related to metabolism like diabetes.

Amruta Swaminathan and Fanning Xia, predoctoral researchers in the lab of Associate Investigator Nicolas Rohner, Ph.D., published a scientific review article on October 26, 2023, in the journal Trends in Genetics. Swaminathan and Xia are conducting their Ph.D. program theses research at The Graduate School of the Stowers Institute for Medical Research on aspects of cavefish development and evolution.

“The experience of writing this review allowed me to dive into the cavefish field in a way I hadn’t before, providing a new perspective on my own research,” said Xia. Similarly, Swaminathan said, “Writing definitely helped with my research, and helped me to fully appreciate the strengths of cavefish as a research system.”

Stowers Predoctoral Researchers participate in advanced education and while furthering their development into successful and independent scientists. Both Swaminathan and Xia found the review writing experience helpful for their own research and for analyzing and disseminating the wealth of literature emerging on cavefish science.

Eye and pigmentation loss between surface fish and cavefish from three different caves.

Advances in characterizing the genetics of cavefish and their surface counterparts are addressed in this review as an ideal system to study adaptation and evolution.

A given organism’s genetics and environment both contribute to its observable traits that includes behavior. While A. mexicanus surface fish and cavefish originally had identical genetics, prolonged periods spent in dark, nutrient limited caves influenced the genes and subsequently the traits of the cavefish. These include the loss of eyes and pigmentation, elevated blood sugar and fat levels, and changes in behavior, a linkage not well studied on evolutionary timescales.

For Swaminathan and Xia, the writing experience was a challenging, yet ultimately, rewarding opportunity for collaboration.

“While it was challenging to assimilate large quantities of information into something coherent, writing this review helped me understand what teamwork entails,” said Swaminathan. “I learned the benefits of discussion and communication that allowed Fanning and I to help each other understand difficult concepts.”

“Working closely with Amruta was a highlight,” Xia said. “It was difficult at times for us to put evidence together, but I think it was a great experience to have such an integrated practice of research, writing, and teamwork.”

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