Spatially restricted activation of the SAX receptor by SCW modulates DPP/TKV signaling in Drosophila dorsal-ventral patterning.
Dorsal-ventral patterning within the embryonic ectoderm of Drosophila requires two TGFbeta ligands, DPP and SCW, and two type I TGFbeta receptors, TKV and SAX. In embryos lacking dpp signaling, increasing the level of TKV activity promotes progressively more dorsal cell types, while activation of SAX alone has no phenotypic consequences. However, SAX activity synergizes with TKV activity to promote dorsal development. Functional experiments suggest the two receptors have different ligands: DPP acts through TKV, and SCW acts through SAX. Furthermore, SOG, a negative regulator of this patterning process, preferentially blocks SCW activity. We propose that spatial regulation of the SAX pathway modulates TKV signaling to create positional information over the embryonic ectoderm.
Neul
J L
JL
Committee on Developmental Biology, University of Chicago, Illinois 60637, USA.
Ferguson
E L
EL
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D004330:Drosophila; D029721:Drosophila Proteins; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D017344:Genes, Insect / Q000502:physiology; D019476:Insect Proteins / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology*; D018125:Receptors, Transforming Growth Factor beta / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000502:physiology*
D029721:Drosophila Proteins; D019476:Insect Proteins; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; C090409:SCW protein, Drosophila; D016212:Transforming Growth Factor beta; C064196:dpp protein, Drosophila; C086338:sax protein, Drosophila; C090169:tkv protein, Drosophila; D017346:Protein Serine-Threonine Kinases