Astyanax mexicanus - Developmental Gene Expression

Astyanax mexicanus, commonly know as the blind Mexican cavefish, is an excellent system to investigate the genetic basis for traits evolving as a consequence of natural environmental pressures. This species includes multiple cave-dwelling populations that have colonized the dark, subterranean environment, and repeatedly evolved a suite of troglomorphic traits, including eye degeneration, loss of pigmentation, alterations in behavior, increased number of taste buds, and an enhanced lateral line system. To investigate the genetic changes associated with cave colonization, we have utilized RNA-seq technologies to compare gene expression variation between surface- and cave-dwelling forms of Astyanax mexicanus. This approach includes a dynamic comparison across four critical stages of early development wherein many troglomorphic-specific traits appear. These analyses dramatically enhance our understanding of phenotypic evolution in the wild, and offer insight to analogous human diseases, including retinal degeneration, pigmentation disorders, craniofacial abnormalities and altered sleep/activity patterns.