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14
Not long after the discovery of RNAi itself, scientists started to try using it to knock
down Drosophila genes in a conditional and inheritable manner (Kennerdell and
Carthew 2000). The pioneer scientist and some of the followers shared a similar
approach to achieve RNAi in Drosophila (Kennerdell and Carthew 2000; Hammond,
Caudy et al. 2001; Adams and Sekelsky 2002; Allikian, Deckert-Cruz et al. 2002). They
constructed an inverted repeat of the target gene sequence and cloned it into a vector that
is able to transcribe the repeat conditionally. The whole construct was injected into the
early stage developing Drosophila embryo by microinjection to generate a transgenic
strain. The inverted repeat structure will fold back upon itself after transcription,
essentially becoming a dsRNA and targeting the gene of interest. The same Dicer and
RISC mechanism will process the dsRNA, and then eventually achieve RNAi. By taking
advantage of the conditional promoter upstream of the inverted repeat, researchers are
able to knock down genes during any stage of development in any tissue. This creative
RNAi design resulted in very effective interference. With only a few improvements
(Adams and Sekelsky 2002; Lee and Carthew 2003), the conditional transcription of
inverted repeats is still the major weapon in scientists’ RNAi arsenal (Allikian, Deckert-
Cruz et al. 2002; Dzitoyeva, Dimitrijevic et al. 2003; Lum, Yao et al. 2003; Dasgupta
and Perrimon 2004; Baeg, Zhou et al. 2005; Gwack, Sharma et al. 2006; Perrimon,
Friedman et al. 2007; Chen, Shi et al. 2008).
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 24 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 14 Not long after the discovery of RNAi itself, scientists started to try using it to knock down Drosophila genes in a conditional and inheritable manner (Kennerdell and Carthew 2000). The pioneer scientist and some of the followers shared a similar approach to achieve RNAi in Drosophila (Kennerdell and Carthew 2000; Hammond, Caudy et al. 2001; Adams and Sekelsky 2002; Allikian, Deckert-Cruz et al. 2002). They constructed an inverted repeat of the target gene sequence and cloned it into a vector that is able to transcribe the repeat conditionally. The whole construct was injected into the early stage developing Drosophila embryo by microinjection to generate a transgenic strain. The inverted repeat structure will fold back upon itself after transcription, essentially becoming a dsRNA and targeting the gene of interest. The same Dicer and RISC mechanism will process the dsRNA, and then eventually achieve RNAi. By taking advantage of the conditional promoter upstream of the inverted repeat, researchers are able to knock down genes during any stage of development in any tissue. This creative RNAi design resulted in very effective interference. With only a few improvements (Adams and Sekelsky 2002; Lee and Carthew 2003), the conditional transcription of inverted repeats is still the major weapon in scientists’ RNAi arsenal (Allikian, Deckert- Cruz et al. 2002; Dzitoyeva, Dimitrijevic et al. 2003; Lum, Yao et al. 2003; Dasgupta and Perrimon 2004; Baeg, Zhou et al. 2005; Gwack, Sharma et al. 2006; Perrimon, Friedman et al. 2007; Chen, Shi et al. 2008). |
