The involvement of a homeobox gene, even-skipped, in the developmental control of cell cycle progression in the trol pathway of Drosophila melanogaster /
Proper cell cycle progression during the development of multicellular organisms such as human is critical for viability and correlates with cell fate determination and differentiation. Stem cells are specialized cells dividing repetitively during development to produce specific cell types in a disti...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731686211&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Proper cell cycle progression during the development of multicellular organisms such as human is critical for viability and correlates with cell fate determination and differentiation. Stem cells are specialized cells dividing repetitively during development to produce specific cell types in a distinct spatiotemporal pattern. Regulation of stem cell proliferation is critical for the understanding of developmental patterning and regeneration after injuries. Fruit flies, Drosophila melanogaster, have been used as a model system to ask how cell cycle progression in stem cells is regulated during development I have focused on studies of the trol pathway of Drosophila melanogaster. This pathway is necessary for the activation of the division of neuronal stem cells, neuroblasts, from quiescence. I identified a homeobox gene, even-skipped (eve), in the trol pathway with a genetic screening. Several mutations in eve dominantly enhanced lethality phenotype and revealed proliferation phenotype of semi-lethal trol[]. trol[] enhancement required a strong reduction in eve function. Lethality enhancement was fully rescued by the introduction of widths eve transient. Interestingly, eve overexpression also caused trol[] lethality enhancement indicating the ratio of trol and eve is important for viability. Proliferation phenotype of intermediate trol[] and trol[] was also enhanced by heterozygous eve[] indicating that trol-eve interaction is not allele specific. Transheterozygous eve[]/eve[] mutations caused a proliferation phenotype. My results consistently suggest that eve, per se, is in the trol pathway. Overexpression of cyclin E rescued proliferation defects of trol[] ; eve[] / + brains. Overexpression of string, Drosophila cdc[] homologue, fully rescued proliferation defects in trol[] ; eve[] / + brains and partially rescued lethality of trol[] ; eve[] / + animals. trol[] ; eve[] / + brains showed less elevated cyclin E and stg expression levels compared to trol[] and control brains monitored by RT-PCR analysis indicating eve controls the expression of cell cycle machinery such as cyclin E and string which are required for the G1/S transitions controlled by the trol pathway. |
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| Item Description: | Vita. "Major Subject: Biochemistry". |
| Physical Description: | xi, 205 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 167-201). |