TGF-beta/BMP superfamily members, Gbb-60A and Dpp, cooperate to provide pattern information and establish cell identity in the Drosophila wing.
Within a developing organism, cells receive many signals which control their proliferation, fate specification and differentiation. One group of such proteins is the TGF-beta/BMP class of related signaling molecules. Based on expression studies, multiple members of this class of ligands must impinge upon the same cells of a developing tissue; however, the role that multiple TGF-beta/BMP ligands may play in directing the development of such a tissue is not understood. Here we provide evidence that multiple BMPs are required for growth and patterning of the Drosophila wing. The Drosophila BMP gene, gbb-60A, exhibits a requirement in wing morphogenesis distinct from that shown previously for dpp, a well-characterized Drosophila BMP member. gbb-60A mutants exhibit a loss of pattern elements from the wing, particularly those derived from cells in the posterior compartment, consistent with the gbb-60A RNA and protein expression pattern. Based on genetic analysis and expression studies, we conclude that Gbb-60A must signal primarily as a homodimer to provide patterning information in the wing imaginal disc. We demonstrate that gbb-60A and dpp genetically interact and that specific aspects of this interaction are synergistic while others are antagonistic. We propose that the positional information received by a cell at a particular location within the wing imaginal disc depends on the balance of Dpp to Gbb-60A signaling. Furthermore, the critical ratio of Gbb-60A to Dpp signaling appears to be mediated by both Tkv and Sax type I receptors.
Khalsa
O
O
Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.
Yoon
J W
JW
Torres-Schumann
S
S
Wharton
K A
KA
D000818:Animals; D052005:Bone Morphogenetic Protein Receptors, Type I; D019485:Bone Morphogenetic Proteins / Q000502:physiology*; D004330:Drosophila / Q000254:growth & development*; D029721:Drosophila Proteins; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000502:physiology*; D007814:Larva / Q000254:growth & development; D009024:Morphogenesis / Q000502:physiology; D009154:Mutation / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000502:physiology*; D014921:Wings, Animal / Q000254:growth & development*
D019485:Bone Morphogenetic Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D016212:Transforming Growth Factor beta; C064196:dpp protein, Drosophila; C089440:gbb protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D052005:Bone Morphogenetic Protein Receptors, Type I