| Project/Area Number |
19570019
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | Nara Women's University |
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Principal Investigator |
YUSA Yoichi Nara Women's University, 理学部, 准教授 (60355641)
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| Co-Investigator(Kenkyū-buntansha) |
IWAGUCHI Shin-ichi 奈良女子大学, 理学部, 准教授 (40263420)
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| Project Period (FY) |
2007 – 2009
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| Project Status |
Completed (Fiscal Year 2009)
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| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2009: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2008: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | 生態学 / 進化 / 遺伝学 / 性決定 / 性比 / 軟体動物 |
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| Research Abstract |
The freshwater snail Pomacea canaliculata shows a large variation in offspring sex ratio. We investigated whether this variation is caused by a small number of sex-determining genes, with two series of experiments. First, we reared F2 offspring from several crosses involving full-sib sisters with the same male, and determined sex ratios of F2. The sex ratios of F2 converged into a few values, indicating that the sex-determining genotypes of the F1 full-sib sisters were also a few. This suggests that the sex in this snail is determined by a few genes rather than polygenes. Secondly, we developed genetic markers to study linkage with the putative sex-determining genes. We found >40 microsatellite loci, and developed four useful markers. These markers were repeatable in PCR, polymorphic and followed Mendelian segregation. We conducted fragment analyses in two populations (Kumamoto and Nara) with these markers. One of them showed significantly different frequencies between males and females in both populations ; it may be in the same linkage group as a sex-determining locus.
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