MELBOURNE, FLA. — The bluegill sunfish and a host of other fish considered invasive species have extra copies of cellular stress response genes in their genomes, new Florida Tech research has found, which may explain why they are more resilient to environmental fluctuations and can outcompete others for shared resources.
Invasive species are an urgent global environmental problem with an estimated worldwide economic impact in the hundreds of billions of dollars.
A team of Florida Tech scientists started with an investigation of two closely related sunfish, the bluegill sunfish and the redear sunfish. While both fish are native to the southeastern U.S., the bluegill has a much wider native range, spanning all the way to Canada. Both sunfish are prized for recreational fishing and have been widely introduced, but only the bluegill sunfish has been described as an invasive species. For example, a gift of bluegill from the mayor of Chicago (bluegill is the Illinois state fish) to the emperor of Japan in 1960 resulted in the species’ introduction to Japanese lakes where they have caused decades of extensive environmental damage.
Analysis of the two sunfish revealed that bluegill contained an unusual number of extra stress response genes. The researchers then identified similar expansions in other fish by examining each of the nearly 100 fish species with well-annotated genomes. Importantly, fish that are considered to be invasive contained, on average, more of these defensive genes.
Having identified a genetic signature that correlates with invasive potential, the team plans to examine whether this signature exists for other species besides fish, and whether the signature can be used to predict which animals need extra precautions to prevent their introduction to new environments.
The research, “Stress Response Gene Family Expansions Correlate with Invasive Potential in Teleost Fish,” was published March 8 in the Journal of Experimental Biology special issue,“Building New Paradigms in Comparative Physiology and Biomechanics.”
The research was led by Taylor Stanley, a graduate student, and Karen Kim Guisbert, a faculty member in biomedical and chemical engineering and sciences. The research was a collaboration between four Florida Tech research groups including Munevver Subasi in mathematics, Ralph Turingan in marine biology and Eric Guisbert and Dave Carroll from biological sciences.
The research was initiated in a summer program in biomathematics funded by the National Science Foundation as part of its Research Experience for Undergraduates program run at Florida Tech by Carroll and Subasi.
Bringing together mathematicians and biologists catalyzed the project and led to critical new insights into the problem, Eric Guisbert noted. Five additional undergraduate students from across the country traveled to Florida Tech and contributed to this research as part of the summer program: Morgan Oneka, Isabela Kernin, Alexandra Lobo, Nicole Higgins and Sabrina Perez.