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5
Female fecundity is greatly affected by many environmental conditions, including
temperature, humidity, and food availability (Alpatov 1932; Kaliss and M.A.Graubard
1936; Siddiqui and C.A.Barlow 1972). Among the most important factors is the influx
of male seminal fluid proteins. A few researchers suggest that male seminal fluid
proteins can increase egg production and decrease female sexual receptivity after mating
has occurred (Wolfner 1997; Chapman 2001; Wolfner 2002; Gillott 2003; Kubli 2003;
Liu and Kubli 2003; Lawniczak and Begun 2004; McGraw, Gibson et al. 2004).
However, the ingredients of seminal fluid are not fully characterized. The fluid contains
the secretions of the male accessory glands and ejaculatory duct (Wolfner 2002; Gillott
2003). Scientists have suggested a list of more than 80 different types of accessory gland
proteins (Swanson, Clark et al. 2001).
A more recent finding suggests that a particular “sex peptide” can increase female egg
production (Chapman, Bangham et al. 2003; Liu and Kubli 2003), and cause release of
juvenile hormone (Moshitzky, Fleischmann et al. 1996). It was previously known that
juvenile hormone may positively affect Drosophila oogenesis and egg production
process (Soller, Bownes et al. 1999; Dubrovsky, Dubrovskaya et al. 2002).
Drosophila PdL mutagenesis
The technique of PdL mutagenesis would not be possible without two crucial steps: P-element
mutagenesis and the tet-on system.
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 15 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 5 Female fecundity is greatly affected by many environmental conditions, including temperature, humidity, and food availability (Alpatov 1932; Kaliss and M.A.Graubard 1936; Siddiqui and C.A.Barlow 1972). Among the most important factors is the influx of male seminal fluid proteins. A few researchers suggest that male seminal fluid proteins can increase egg production and decrease female sexual receptivity after mating has occurred (Wolfner 1997; Chapman 2001; Wolfner 2002; Gillott 2003; Kubli 2003; Liu and Kubli 2003; Lawniczak and Begun 2004; McGraw, Gibson et al. 2004). However, the ingredients of seminal fluid are not fully characterized. The fluid contains the secretions of the male accessory glands and ejaculatory duct (Wolfner 2002; Gillott 2003). Scientists have suggested a list of more than 80 different types of accessory gland proteins (Swanson, Clark et al. 2001). A more recent finding suggests that a particular “sex peptide” can increase female egg production (Chapman, Bangham et al. 2003; Liu and Kubli 2003), and cause release of juvenile hormone (Moshitzky, Fleischmann et al. 1996). It was previously known that juvenile hormone may positively affect Drosophila oogenesis and egg production process (Soller, Bownes et al. 1999; Dubrovsky, Dubrovskaya et al. 2002). Drosophila PdL mutagenesis The technique of PdL mutagenesis would not be possible without two crucial steps: P-element mutagenesis and the tet-on system. |
