CONSERVATION OF DISHEVELLED STRUCTURE AND FUNCTION BETWEEN FLIES AND MICE - ISOLATION AND CHARACTERIZATION OF DVL2

The segment polarity gene dishevelled (dsh) of Drosophila is required for pattern formation of the embryonic segments and the adult imaginal discs. dsh encodes the earliest-acting and most specific known compon ent of the signal transduction pathway of Wingless, an extracellular s ignal homologous to Wnt1 in mice. We have previously described the iso lation and characterization of the Dvl1 mouse dsh homolog. We report h ere the isolation of a second mouse dsh homolog, Dvl2, which maps to c hromosome 11. The Dvl2 amino acid sequence is equally related to the d sh sequence as is that of Dvl1, but Dvl2 is most similar to the Xenopu s homolog Xdsh. However, unlike the other vertebrate dsh homologs. Lik e the other genes, Dvl2 is ubiquitously expressed throughout most of e mbryogenesis and is expressed in many adult organs. We have developed an assay for dsh function in fly embryos, and show that Dvl2 can parti ally rescue the segmentation defects of embryos devoid of dsh. Thus, D vl2 encodes a mammalian homolog of dsh which can transduce the Wingles s signal.