The tissue polarity gene nemoplays multiple roles during development and participates in Wg and Fz signaling. E.M. Verheyen , I. Mirkovic , S.J. MacLean , B.C. Andrews , D.C. Bessette , C. Mackinnon , Z. Ursuliak. Dept. Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.

   Wnt signaling is required during the patterning of diverse organisms. The Nemo kinase has recently emerged as a conserved regulator of Wnt in worms and mice. nemowas originally identified in Drosophila through its involvement in planar polarity in the eye. We have extended the analysis of nemo in Drosophila and found that it participates in multiple developmental processes. It is required during wing development for vein patterning and hinge development. In the wing we observe genetic interactions between nemoand mutations in the Notch, Wingless, Frizzled and Decapentaplegic pathways. In addition, we find a negative regulatory effect on several components of the Wingless pathway, consistent with the role observed for the vertebrate Nemo homolog. nemomutations also cause polarity defects in the adult wing, supporting the original finding that nemo is a tissue polarity gene. The expression of nemoduring embryogenesis is dynamic and dsRNA inhibition studies indicate that nemois essential during embryogenesis and elimination of nemo activity leads to defects in patterning.