MSc Exit Seminar – Bianca Scuric (Ringuette lab)

MSc Exit Seminar

Monday January 18^th, 10:10 am – Ramsay Wright Building, Rm. 432

Bianca Scuric (Ringuette lab) 

“ Role of SPARC in Drosophila melanogaster basal lamina homeostasis“

Abstract

SPARC is a multifunctional, evolutionarily conserved, collagen- and growth factor-binding glycoprotein. Previous studies in our laboratory demonstrated that SPARC is required in Drosophila melanogaster for proper larval development and maintenance of fat body homoeostasis. Through the use of RNA interference, I have further characterized a SPARC knockdown in the larval fat body, with an emphasis on ultrastructural adipocyte morphology and basal lamina integrity. Loss‐of‐function analyses revealed remodeling of adipocytes characterized by cell rounding and dense accumulation of fibrous matrix material beneath a basal lamina of abnormal thickness. In addition to dramatic changes in cell morphology, adipocytes of SPARC deficient larva show increased deposition of collagen IV and other basal lamina components (Martinek et al., 2011; Shahab et al., 2015). How collagen IV assembles into an organized network in basal lamina remains unclear. I sought to elucidate the potential intra- and extracellular functions of SPARC in collagen IV assembly and maturation within the basal lamina surrounding larval adipocytes. To perform in vivo structure function analysis, I generated five mCherry tagged SPARC constructs which failed to rescue loss-of-function and SPARC-null mutants. Although fluorescence was observed in all transgenic animals, stability of the SPARC protein was comprised by the C-terminal tag. 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.

Ramsay Wright is a wheelchair accessible building.