A better understanding of how organisms adapt to change in their environment has wide implications in many fields of study, according to an IU news release. These areas include molecular evolution, climate change and medicine, particularly regeneration and healing.
The study is published in the journal “Molecular Biology and Evolution.”
The focus of the study is phenotypic plasticity, which refers to the ability that some organisms have to alter their observable characteristics in response to changes in the environment, according to the University.
“Phenotypic plasticity is an incredibly important ability,” said Joe Shaw, associate professor at the IU School of Public and Environmental Affairs and the paper’s lead author, in the release. “Think in terms of the metamorphosis that butterflies go through, except in this case the shift is triggered by a change in the environment.”
Shaw directed the study along with Tom Hampton, senior bioinformatics analyst at Dartmouth’s Geisel School of Medicine. Co-authors included Nathan Keith and Stephen Glaholt of SPEA.
Within the study, the team observed how the Atlantic killifish modifies its gills based on whether it is in freshwater or seawater.
Shaw had previously observed that killifish are more sensitive to arsenic during shifts in the salinity of their habitat.
Fish living in either one of these environments can tolerate arsenic reasonably well, but the arsenic affects their plastic response to the changes in environment, which makes it hard for the fish to adjust and survive.
Based on these findings, the researchers used arsenic to identify the genes necessary for this plasticity.
Exposing the killifish to arsenic during their salt acclimation identified many genes involved in the changes. The results suggest strict control of these genes.
“If you take two fish that are different in many ways, and these two fish just changed over from living in freshwater to seawater, what’s striking is how identical their gills are if you look at them under a microscope or test to see how they are functioning,” Shaw said in the release.
Plasticity-enabling genes seem to operate in unusually simple networks, the researchers reported. The development of these networks is also affected by the environment in which the killifish lives. For example, fish living entirely in freshwater had less control of their plasticity-enabling genes.
The team is now working to find ways to apply their results to other fields.
Anna Hyzy
