Article,
A Novel Role for Mc1r in the Parallel Evolution of Depigmentation in Independent Populations of the Cavefish Astyanax mexicanus
PLoS Genet, 5 (1): e1000326 (January 2009)
DOI: 10.1371/journal.pgen.1000326
Abstract
<title>Author Summary</title>
<p>As we approach the 150th year since publication of <italic>On the Origin of Species</italic>, understanding the genetic architecture underlying evolutionary change remains an important challenge. When an organism enters a completely new environment or ecological niche, certain traits are no longer necessary for survival, while other new traits become critical for maintaining fitness. An example of such a transition is provided by cave animals. Many disparate taxa (e.g., crustaceans, salamanders, fish) have colonized caves, presumably to escape predation or expand populations into an unexploited niche. Strikingly, similar traits evolve convergently despite significant phylogenetic distance between these organisms. Caves provide a unique environment including the absence of light, few predators, few sources of food, etc. Under these conditions, one observes striking changes in morphology including reduction in eyes, expansion of non-visual sensory systems, and a suite of metabolic and behavioral changes. To understand the genetic underpinnings of these shifts, we have established the blind Mexican cave tetra, <italic>A. mexicanus</italic>, as a genetic system. In this paper, we use this system to investigate a classic morphological feature in these animals, depigmentation. We identify the gene <italic>Mc1r</italic> as being responsible for reduction in melanin content in multiple caves.</p>
