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15
However, as with all other molecular biology techniques, RNAi by transcription of
inverted repeat has its own disadvantages.. Researchers often have to inject hundreds of
embryos, hoping to obtain one successful transformant. It also takes weeks or even
months to balance the successful transformant into a homozygous strain before it can be
used to knock down their favorite gene in a live fly. Another research group tried an
alternative approach, inducing RNAi by simply injecting dsRNA into the abdomen of
anesthetized adult Drosophila (Dzitoyeva, Dimitrijevic et al. 2001). The same research
group used this method to characterize the molecular functions of a few genes in the
central nervous system (Dzitoyeva, Dimitrijevic et al. 2001; Dzitoyeva, Dimitrijevic et
al. 2003). This new method is able to knock down a gene of interest with reasonable
efficacy in just a few days, compared to weeks or months for the traditional technique.
However, perhaps because the intra-abdominal dsRNA injection on adult flies requires
mastery of fly injection techniques, until now, other than this original research group,
reports of successful adult RNAi injection in Drosophila are still very rare.
Object Description
| Title | Characterization of Drosophila longevity and fecundity regulating genes |
| Author | Li, Yishi |
| Author email | yishili@usc.edu; yishili@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Molecular & Computational Biology |
| School | College of Letters, Arts and Sciences |
| Date defended/completed | 2008-08-19 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-10-31 |
| Advisor (committee chair) | Tower, John |
| Advisor (committee member) |
Finkel, Steven E. Aparicio, Oscar Martin Longo, Valter D Comai, Lucio |
| Abstract | The regulation of Drosophila melanogaster longevity and fecundity involves many factors. Longevity is governed by oxidative stress, stem cell loss, dietary restriction, the insulin/IGF-1 pathway, and other factors. Fecundity is also regulated by multiple tissues and factors, including the germline stem cells and stem cell niche, the fat body, yolk proteins, and sex peptides. The fecundity of wild type female Drosophila gradually declines during aging, suggesting a common pathway regulating longevity and fecundity machinery. Since both mechanisms involve multiple factors, sorting through the Gordian’s knot is a formidable task. Using a PdL mutagenesis approach, I screened for a specific phenotype in thousands of independent mutant strains to examine both regulatory networks simultaneously. Two novel genes, magu and hebe, were identified and characterized to regulate longevity and fecundity. While Drosophila lifespan was extended upon the induction of these genes, fecundity increase requires that the gene induction be in an ideal range to show the expected phenotypic change. I also performed several other projects, including studying the lifespan extension effect of dIAP2, characterization of a Drosophila gut driver strain, and intra-abdominal RNAi injection in adult Drosophila. These projects provided us insight on longevity, fecundity, anti-apoptosis, stem cell biology, RNAi and other aspects of Drosophila research. In sum, Drosophila melanogaster, as a model organism for molecular biology and genetics study, will continue to contribute to the scientific community. |
| Keyword | Drosophila; longevity; fecundity |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m1735 |
| Contributing entity | University of Southern California |
| Rights | Li, Yishi |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@lib.usc.edu |
| Filename | etd-Li-2382 |
| Archival file | uscthesesreloadpub_Volume44/etd-Li-2382.pdf |
Description
| Title | Page 25 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 15 However, as with all other molecular biology techniques, RNAi by transcription of inverted repeat has its own disadvantages.. Researchers often have to inject hundreds of embryos, hoping to obtain one successful transformant. It also takes weeks or even months to balance the successful transformant into a homozygous strain before it can be used to knock down their favorite gene in a live fly. Another research group tried an alternative approach, inducing RNAi by simply injecting dsRNA into the abdomen of anesthetized adult Drosophila (Dzitoyeva, Dimitrijevic et al. 2001). The same research group used this method to characterize the molecular functions of a few genes in the central nervous system (Dzitoyeva, Dimitrijevic et al. 2001; Dzitoyeva, Dimitrijevic et al. 2003). This new method is able to knock down a gene of interest with reasonable efficacy in just a few days, compared to weeks or months for the traditional technique. However, perhaps because the intra-abdominal dsRNA injection on adult flies requires mastery of fly injection techniques, until now, other than this original research group, reports of successful adult RNAi injection in Drosophila are still very rare. |
