Meeting Abstract

P3.58  Thursday, Jan. 6  Eye and pigment loss in the isopod cave crustacean, Asellus aquaticus PROTAS, M. E.*; TRONTELJ, P.; PATEL, N. H.; UC Berkeley; University of Ljubljana; UC Berkeley mprotas@berkeley.edu

We are investigating the genetic basis of morphological evolution in the fascinating group of cave animals. There are many different types of cave animals including fish, crustaceans, spiders, and salamanders having some degree of pigment and eye loss. The particular species we are studying is Asellus aquaticus, a freshwater, cave dwelling isopod crustacean. This species has both cave and surface dwelling forms with remarkable morphological differences between populations. The cave form has reduced or absent eyes, no pigmentation, elongated legs, elongated antennae, longer sensory cells on the antennae, and reduced bristles. We have generated crosses between the cave and surface forms, identified genetic markers associated with candidate genes in eye, pigment, and appendage development, and established a linkage map for this species. In addition, we have mapped loci of large effect for three different pigmentation traits and the phenotype of complete eye loss. Strikingly, there appears to be multiple genetic paths producing either identical (in the case of pigment loss) or similar (in the case of eye loss/ reduction) phenotypes within the particular cave population we are investigating. Asellus aquaticus is proving to be a great system to study the genetic basis of morphological evolution as well as parallel evolution within populations of Asellus, between independently evolved cave populations of Asellus, and with other species of cave animals, both invertebrates and vertebrates.