Cave fish as a model to elucidate the genetic basis of the evolution of behavior
Final Report Abstract
In summary we show here that altered levels of HSP90 in natural surface populations of Astyanaxmexicanus produce altered phenotypes at low penetrance, consistent with previous work on natural populations. Evidence however, that different levels of HSP90 can increase variation of an adaptive trait in natural population has been lacking. We detected an increase of variation in eye size in natural surface fish population when treated with Radicicol (or environmental stress) and most importantly could show that in cavefish populations the alleles which are responsive to HSP90 have been selected for in the transition from surface to cave forms, leaving only alleles which tend to produce a smaller orbit when released from their normal HSP90 interactions. This makes an involvement of HSP90 in cavefish evolution plausible and would provide an actual case in nature for Waddingtonsclassic theory of the role of canalization in evolution.
