| Project/Area Number |
13640629
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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 |
生態
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
YAMAUCHI Atsush KYOTO UNIVERSITY, Center for Ecological Research, Associate Prof., 生態学研究センター, 助教授 (40270904)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Evolution of Sex / Frequency Dependent Selection / Vertical Transmission / Polyploid / Theory / Model / 同質倍数体 / triploid bridge / triploid block / 進化 / 染色体 / 数理モデル / 3倍体ブリッジ / 3倍体ブロック / ミトコンドリアゲノム / 核ゲノム / 遺伝子の移行 |
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| Research Abstract |
1.Facultative sexual reproduction under frequency-dependent selection on a single locus.
Hamilton (1980) theoretically studied evolution of sex from a viewpoint of host-parasite interaction. He clarifies that when a strong negative frequency selection works on a certain locus, it possibly results in evolution of sex so as to change combinations of alleles. He considered that the selection was resulted from host-parasite interaction. I theoretically analyzed a possibility that the above factor can evolve facultative sexual strategy, in which an individual produces both male and female offspring simultaneously.
2.Factors affecting binary sex evolution with respect to avoidance of vertical transmission of deleterious intracellular parasites.
Hutson and Low (1993) theoretically studied a role of cytoplasmic parasites in evolution of sex. They pointed out that organisms initially evolved a uniparental cytoplasmic inheritance system so as to avoid vertical transmissions of deleterious intracellular parasites. Subsequently, mating preference evolved between individuals with and without cytoplasmic inheritance, resulting in evolution of sex. I theoretically analyzed how this evolutionary pencess is influenced by various characteristics of host-intracellular parasites
3.Triploid bridge and role of parthenogenesis in the evolution of autopolyploidy.
Polyploidization has played an important role in evolution of organisms, especially in plant evolution, although evolutionary process of polyploidization has been still not clear. Since mating between diploid and tetraploid individuals results in triploid offspring, an existence of triploid individuals is considered as an important key factor. Nevertheless, in plant species, triploid individuals generally have only low viability and fertility, which possibly restricts polyploidization process. I theoretically studied a role of parthenogenesis in promotion of polyploidization process, by using mathematical model.
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