Contact-dependent Growth Factor Signaling Mediated by Heparan Sulfate Proteoglycans in Drosophila in vivo

Abstract

Heparan sulfate proteoglycans (HSPGs) are special type of glycoproteins which play important roles in development, such as regulation of growth factor signaling and maintenance of the stem cells. Nakato Lab recently found that Dally, a Drosophila HSPG is expressed in the niche cells and regulates BMP signaling in directly contacting stem cells in the germline stem cell niche of the Drosophila ovary. Thus, Dally can mediate signaling in trans in directly contacting cells. In order to search for tissues where Dally-expressing cells have direct contact with cells expressing growth factors such as bone morphogenetic proteins (BMPs) and fibroblast growth factors (FGFs), we established a novel system to detect cell-cell contact using split-GFP (spGFP) method in vivo. The system effectively detected the interface of Dally-expressing and BMP-expressing cells.