Thesis (Master, Biology) -- Queen's University, 2010-07-10 14:30:31.444 / Neuropeptides are found in the nervous systems of both invertebrates and vertebrates. The function of many of these neuropeptides and how they interact with their receptors is largely unknown. Through the use of genetically manipulatable organisms such as Drosophila, we are able to analyze the function and roles of these peptides to help us better understand their regulation of behavioural and physiological functions.
To functionally analyze genes that encode neuropeptides and their receptors in D. melanogaster, we knocked down genes via RNAi in specific tissues using the UAS/Gal4 system. RNAi lines for FGLamide-allatostatins (ASTs) and their cognate receptors, Dar-1 and Dar-2 were examined for foraging defects, for transcript levels, and triglyceride content. In addition, RNAi lines for Drosophila PISCF-AST and its cognate receptors, Drostar-1 and Drostar-2 alongside sNPF receptor and a neuropeptide-Y like receptor were analyzed for their effect on juvenile hormone biosynthesis.
Dar-1 and FGLamide-AST RNAi lines showed a significant foraging defect similar to that of the dweller phenotype seen in NPR-9 (AST receptor-like) mutants in C. elegans. These lines also show a decrease in for transcript levels suggesting that the foraging defect seen may also be tied into rover and sitter phenotypes. Unlike npr-9 mutants in the worm, larvae showing a foraging defect on food did not show an accumulation of intestinal lipids. Ring gland expression of FGLamide-AST, Dar-1, and Dar-2 RNAi did not show a significant effect on JH biosynthesis in either stage. Similar to these results, ubiquitous expression of PISCF-AST RNAi did not show an effect on JH. However, ubiquitous expression of Drostar-1 and Drostar-2 RNAi showed an inhibitory effect on JH biosynthesis in larvae, but a stimulatory effect in adult females. Also, Drm-sNPF-R RNAi showed a stimulatory effect in 7-day old adult females, while NepYr RNAi showed an inhibitory effect in both stages. Our data suggests that PISCF ASTs regulate JH biosynthesis in the fruit fly and the regulatory effect of these peptides on JH biosynthesis differs depending on the stage of the animal. The effect of sNPF and NPY receptors on JH suggests a link between JH regulation and the insulin signaling pathway. / Master
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/5937 |
| Date | 23 July 2010 |
| Creators | Wang, Christine |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)), Dr. William G. Bendena, Biology |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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