SPARC is a collagen‐binding, matricellular glycoprotein with diverse roles in tissue remodeling and development. Previous studies have demonstrated that SPARC is required in Drosophila for larval development and maintenance of the fat body, an organ that incorporates endocrine, growth and immune functions. I have characterized effects of loss and knockdown of SPARC in the fat body. Loss‐of‐function analyses revealed remodeling of adipocytes demarcated by cell rounding and dense accumulation of extracellular matrix (ECM) beneath an abnormally thick basement membrane. Remodeling of adipocytes
mediated by expression of matrix metalloproteinase 2 (MMP2) was found to cause ECM breakdown and accumulation of hemocytes, indicating endogenous fat body remodeling is mechanistically distinct from that which occurs upon silencing of SPARC. Knockdown of the lysyl hydroxylase, dPlod, in the fat body, revealed abnormal intracellular co‐localization of SPARC with Collagen IV, but not with Laminin. The data indicate SPARC is required for ECM homeostasis during development.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OTU.1807/33330 |
| Date | 20 November 2012 |
| Creators | Baratta, Cristina |
| Contributors | Ringuette, Maurice |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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