2020 Fiscal Year Final Research Report
Geographic variation of karyotypes involving circular overlaps in Japanese harvestmen (Arachnida: Opiliones) with their taxonomic revisions
| Project/Area Number |
17K07534
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Biodiversity/Systematics
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| Research Institution | Tottori University |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2021-03-31
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| Keywords | 地理的変異 / 染色体 / 交雑帯 / 環状重複 / 種分化 / ザトウムシ |
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| Outline of Final Research Achievements |
Harvestmen (Arachnida, Opiliones) are suitable animals to understand chromosomal speciation due to their enormous geographical diversity in the number of chromosomes and external morphology even in a single species. In this study, chromosomal data were accumulated for the unstudied areas for Gagrellula ferruginea, the Leiobunum curivipalpe-species group, and Nelima genufusca-species group, and so on. Nature of the several chromosomal hybrid zones have been also analysed. Population genomics surveyed for two thelytokous harvestmen, L. manubriatum and L. globosum revealed that their thelytoky was of facultative, and females of the species mate with two males on average in the wild.
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| Free Research Field |
動物分類学
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| Academic Significance and Societal Importance of the Research Achievements |
染色体種分化は1970-1980年代に種分化の1プロセスとして注目されたが，最近は研究があまり進展していない。1990年代以降，野外集団遺伝学に関心のある研究者の多くが解析手法として核型分析からDNAに移行したのが一因と考えられる。ザトウムシ類は染色体数の地理的分化がきわめて顕著な動物群であり，染色体情報なしには，別種か同種かの識別も困難であった。この研究ではこれまで未調査であった地域についても染色体情報を得たことにより，本類の分類学的整理の基礎を確立できた。また，染色体交雑帯でヘテロ接合核型が超優性を示す例をはじめて示した。産雌単為生殖の進化生物学的問題に新視点を提供できた.
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