Studies on genetic characteristics of Drosophila simulans.
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||KYOTO INSTITUTE OF TECHNOLOGY|
YAMAMOTO Masa-toshi Drosophila Genetic Resource Center, Kyoto Inst. Technology, Professor, ショウジョウバエ遺伝資源センター, 教授 (10142001)
|Project Period (FY)
1997 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥700,000 (Direct Cost : ¥700,000)
|Keywords||speciation gene / hybrid lethality / Drosophila simulans / spermatogenesis / chromosome aberration / transposon / 雑種致死 / 救済遺伝子 / Lhr遺伝子 / 性比異常|
Drosophila simulans is one of the closely related species to Drosophila melanogaster which is the best analyzed genetic material used widely in many different fields of biological research. The findings obtained from Drosophila melanogaster is tend to understand to be general properties of genetic systems. However there exist a few characteristics specific to D. simulans but no similar phenotype had been described in D. melanogaster. It is important to characterize the species specific biological phenomena in order to understand the speciation mechanisms from the genetics view points. The research has been carried out for the following biological phenomena known to be restricted to D. simulans.
1. sex-ratio genes : In spermatogenesis the Y chromosome bearing sperms are eliminated and produced mostly the X chromosome bearing sperms. Electron microscopical studies demonstrated abnormalities in the chromatin segregation and condensation.
2. Cytological mapping of the Lhr gene : Hybrid femal
es from the cross between D. melanogaster females and D. simulans males are lethal. The Lethal hybrid rescue (Lhr) gene rescues the lethality and lets the hybrids to survive to adulthood. Because no homologous gene to Lhr has been identified in D. melanogaster, cytological location of the gene had been analyzed by making hybrids using some newly isolated visible mutations of D. simulans.
3. Synthesis of chromosome aberrations and making a balancer chromosome stock : Two third-chromosome inversions, a ring X chromosome including a large inversion have been made and analyzed genetically and cytologically. Marked Y chromosomes were also synthesized and fragmented Y chromosomes were produced.
4. Characterization of the ninja transposon : An extensive molecular survey demonstrated that the ninja retrotransposon is D. simulans specific transposon.
5. Molecular analysis of highly unstable mutation of white-Sa : A highly unstable (10ィイD1-2ィエD1) white mutation (wィイD1S2ィエD1) has been analyzed and shown to carry an about 3kb mariner-like insertional. Less
Research Output (18results)