Meeting Abstract

91.8  Thursday, Jan. 7  Wnt signaling and appendage development in the sepiolid squid Euprymna scolopes NÖDL, Marie T*; FARFAN, Claudia B; DE COUET, H Gert; Department of Theoretical Biology, University of Vienna, Austria; Departmento de Acuicultura, CICESE, Mexico; Department of Zoology, University of Hawaii at Manoa, USA couet@hawaii.edu

The Wnt pathway is an evolutionary conserved signaling pathway, which plays a pivotal role in a large number of developmental processes, such as the establishment of the body axes and the establishment of limb polarity. During the development of the vertebrate limbs, members of the wnt gene family play a crucial role in the induction of limb formation, as well as the growth and the establishment of the dorsal-ventral axis. In Drosophila melanogaster wnt genes mediate the organizing activity of the dorsal-ventral boundary of the wings and specify the dorsal-ventral and proximo-distal axis of the legs, respectively. Therefore, despite the profound differences in the structure of adult appendages found in vertebrates and arthropods the Wnt pathway maintains a central role in the appendage development of both phyla. Cephalopods are a highly derived class within the mollusks. During the course of evolution members of this group underwent significant changes of their body plan, including subdivision of the ventral foot into prehensile arms, tentacles, and a funnel tube, which are considered true morphological novelties. In order to understand the molecular mechanisms that underlie evolutionary innovation we isolated a number of wnt homologs from the Hawaiian bobtail squid Euprymna scolopes and examined their expression by in situ hybridization. We will show that distinct Euprymna wnt paralogues are strongly expressed during the development of the arms and tentacles of the squid, suggesting that the Wnt pathway plays an important role in limb patterning within the cephalopod mollusks.