Funcion de dumbfounded, sticks and stones y polychaetoid en los nefrocitos en guirnalda de drosophila melanogaster

Abstract

Dumbfounded (Duf) and Sticks and stones (Sns) are members of the IRM family of transmembrane proteins in Drosophila, that play crucial roles in heterotypic recognition between different cell types. For instance, they mediate the aggregation of founder and fusion competent myoblasts previous to the fusion process and cell arrangements that pattern the Drosophila eye. In the present work, we show that Duf and Sns are coexpressed in garland nephrocytes where they form a highly specialized cell junction, the nephrocyte diaphragm, which spans the openings of the nephrocyte's labyrinthine channels. We further show that Duf and Sns are necessary for the development of this diaphragm, as it has also been described for their vertebrate orthologues NEPH1 and nephrin in kidney podocytes. Furthermore, we demonstrate that in nephrocytes Duf and Sns participate in a multiprotein complex that is different to the one that operates during muscle development and that share many of the constituents of the NEPH1/nephrin complex in podocytes. One of these is Polychaetoid, the orthologue of Zonula Occludens-1, which associates with Duf and plays an important role in the formation of nephrocyte diaphragms.