Type IV collagens and Dpp: positive and negative regulators of signaling

Decapentaplegic (Dpp) is an essential morphogen in the TGFbeta/BMP superfamily, which patterns fields of cells during multiple stages of Drosophila development, including the ovary and embryo. We have found that type IV collagens bind to Dpp and regulate its signaling during these two developmental stages. This article primarily focuses on type IV collagens and embryonic Dpp signaling to discuss aspects of the type IV collagen mutant phenotype in the context of additional data from the field. In addition, the restriction of Dpp signaling in the ovary by type IV collagens is described, as the differences between the embryonic and ovarian Dpp sources result in distinct effects of collagen IV proteins in the two systems.