Transgenic Analysis of the Smad Family of TGFb Signal Transducers in Drosophila melanogaster.pdfVIP

Copyright  2001 by the Genetics Society of America Transgenic Analysis of the Smad Family of TGF- Signal Transducers in Drosophila melanogaster Suggests New Roles and New Interactions Between Family Members † 1 2 Raymond M. Marquez,* Matthew A. Singer, , Norma T. Takaesu,* W. Ross Waldrip,*, Yevgenya Kraytsberg† and Stuart J. Newfeld*,‡ *Department of Biology, Arizona State University, Tempe, Arizona 85287, † The Biological Laboratories, Harvard University, Cambridge, Massachusetts 02138 and ‡ Graduate Program in Molecular and Cellular Biology, Arizona State University, Tempe, Arizona 85287 Manuscript received November 3, 2000 Accepted for publication December 15, 2000 ABSTRACT Smad signal transducers are required for transforming growth factor--mediated developmental events in many organisms including humans. However, the roles of individual human Smad genes (hSmads) in development are largely unknown. Our hypothesis is that an hSmad performs developmental roles analo- gous to those of the most similar Drosophila Smad gene (dSmad). We expressed six hSmad and four dSmad transgenes in Drosophila melanogaster using the Gal4/UAS system and compared their phenotypes. Phylogenetically related human and Drosophila Smads induced similar phenotypes supporting the hypothe- sis. In contrast, two nearly identical hSmads generated distinct phenotypes. When expressed in wing imaginal disks, hSmad