| SPARC is a multifunctional, evolutionarily conserved, collagen- and growth factor-binding glycoprotein that is required in Drosophila melanogaster for proper larval development and maintenance of fat body homoeostasis. I have engineered a SPARC RNAi knockdown in the larval fat body, with an emphasis on ultrastructural adipocyte morphology and basal lamina integrity, resulting in adipocyte remodeling characterized by cell rounding and accumulation of fibrous matrix material. SPARC deficient larva show increased deposition of collagen IV and other basal lamina components. How collagen IV assembles into an organized network in basal lamina remains unclear. In seeking to elucidate the potential intra- and extracellular functions of SPARC in this context, I generated five mCherry tagged SPARC constructs which failed to rescue SPARC-null mutants. Together, the data compiled by myself and others in the lab indicate that SPARC is required to maintain adipocyte morphology and basal lamina homeostasis during larval development. |
