The role of rho family GTPases in development: lessons from Drosophila melanogaster.

It has become increasingly clear in the last few years that the Rho family GTPases regulate cytoskeleton rearrangements that are essential for a variety of morphogenetic events associated with the development of multicellular organisms. In particular, Drosophila has provided an excellent in vivo system for deciphering the signaling pathways mediated by Rho GTPases, as well as establishing the role of these pathways in numerous developmental processes. Continued use of this system will undoubtedly lead to the identification of additional Rho signalling components and information regarding the function and organization of the Rho signaling pathways in tissue morphogenesis. The striking similarity between Drosophila and mammalian Rho signaling components identified thus far indicates that the Rho pathways are highly conserved in evolution. Therefore, the findings from the Drosophila system can be extrapolated to higher organisms, including humans. Combined with the rapid progress in the human and Drosophila genome projects, these findings should contribute greatly to our understanding of mammalian Rho GTPase signaling pathways and their roles in normal development and pathological conditions.