Meeting Abstract

P1.90  Saturday, Jan. 4 15:30  Mechanisms of axial polarity modification during postembryonic development of the basal bilaterian Convolutriloba retrogemma CROWTHER, L. N. *; SIKES, J. M.; University of San Francisco; University of San Francisco lncrowther@dons.usfca.edu

Acoel flatworms in the genus Convolutriloba are notable in their varied manners of asexual reproduction that dramatically modify the A-P axis postembryonically. For example, C. retrogemma reproduces via reversed polarity budding where progeny develop from budding sites with a complete reversal of the A-P axis of the parent. This process is thought to require a brief absence of polarity then reestablishment of a novel AP axis in the developing bud. Previous research has indicated that Wnt and Hedgehog signal transduction may play roles in the loss and reestablishment of A-P polarity in C. retrogemma, but little is known about the specific roles of these signaling pathways in the budding process. We have manipulated both Wnt and Hedgehog pathways through the use of RNA interference and pharmacological inhibitors to reveal distinct loss of axial polarity that appears to mediate the reversal of the pre-existing A-P axis. In clarifying the roles of these two signaling pathways during axial repolarization during acoel post-embryonic development, this study suggests both Wnt and Hedgehog signals specify axial polarity in these basal bilaterians.