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119
Relative to expression in somatic stem cells, magu is enriched 20.5-fold in germ line
stem cells (Terry, Tulina et al. 2006). Could this mean that magu is also involved in the
spermatogenesis process? According to an NCBI BLAST search (McGinnis and
Madden 2004), magu has many orthologs in various species including worm, fruit fly,
dog, rat, and human. The rat and human orthologs are named SMOC2 (SPARC related
modular calcium binding 2) and Smap2, respectively. A group of researchers reported
that the expression level of SMOC2 was high in the early embryo (Vannahme, Gosling
et al. 2003; Mager, Schultz et al. 2006) and ovary (Vannahme, Gosling et al. 2003) of
mice, consistent with the expression level data of magu and its potential role in early
embryo development. Smap2, the human ortholog of magu, is reported to be more
highly expressed in aorta than in any other tissue. It is also expressed in muscle tissue,
reproductive tissues, digestive tissues, and secretory tissues (Nishimoto, Hamajima et al.
2002). These data also indicated that that Smap2 mRNA was up-regulated during
neointima formation in a rat carotid endarterectomy model, suggesting smap2’s potential
role in the progression of atherosclerosis in the aorta. Another study reported that
SMOC2 is a novel angiogenic factor that can stimulate endothelial cell proliferation,
migration, and potentiates angiogenic effects of growth factors, which leads to the
formation of blood vessels (Rocnik, Liu et al. 2006). The orthologs in these species
share the following conserved domains: the Kazal type serine protease inhibitor,
Thyroglobulin type I repeats, and the SPARC extracellular Ca2+ binding domain. These
domains are also found on magu, according to protein motif searches (Kanehisa, Goto et
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 129 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 119 Relative to expression in somatic stem cells, magu is enriched 20.5-fold in germ line stem cells (Terry, Tulina et al. 2006). Could this mean that magu is also involved in the spermatogenesis process? According to an NCBI BLAST search (McGinnis and Madden 2004), magu has many orthologs in various species including worm, fruit fly, dog, rat, and human. The rat and human orthologs are named SMOC2 (SPARC related modular calcium binding 2) and Smap2, respectively. A group of researchers reported that the expression level of SMOC2 was high in the early embryo (Vannahme, Gosling et al. 2003; Mager, Schultz et al. 2006) and ovary (Vannahme, Gosling et al. 2003) of mice, consistent with the expression level data of magu and its potential role in early embryo development. Smap2, the human ortholog of magu, is reported to be more highly expressed in aorta than in any other tissue. It is also expressed in muscle tissue, reproductive tissues, digestive tissues, and secretory tissues (Nishimoto, Hamajima et al. 2002). These data also indicated that that Smap2 mRNA was up-regulated during neointima formation in a rat carotid endarterectomy model, suggesting smap2’s potential role in the progression of atherosclerosis in the aorta. Another study reported that SMOC2 is a novel angiogenic factor that can stimulate endothelial cell proliferation, migration, and potentiates angiogenic effects of growth factors, which leads to the formation of blood vessels (Rocnik, Liu et al. 2006). The orthologs in these species share the following conserved domains: the Kazal type serine protease inhibitor, Thyroglobulin type I repeats, and the SPARC extracellular Ca2+ binding domain. These domains are also found on magu, according to protein motif searches (Kanehisa, Goto et |
