Local BMP receptor activation at adherens junctions in the Drosophila germline stem cell niche.

摘要: According to the stem cell niche synapse hypothesis postulated for mammalian haematopoietic system, spatial specificity of signals is maximized by subcellularly restricting signalling cadherin-based adherens junctions between individual and cells. However, such a has never been observed directly, in part, because tools detect active growth factor receptors with subcellular resolution were not available. Here we describe novel fluorescence-based reporter that directly visualizes bone morphogenetic protein (BMP) receptor activation show Drosophila testis BMP signal transmitted preferentially at hub germline cells, resembling proposed organization. Ligand secretion involves exocyst complex Rap activator Gef26, both which are also required Cadherin trafficking towards junctions. We, therefore, propose local generation achieved through shared use transport machinery.