Reinforcement of reproductive isolation in haplodiploid spider mites

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06810
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: University of Tsukuba
• Principal Investigator: Sato Yukie 筑波大学, 生命環境系, 助教 (60414629)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 種分化 / 接触帯 / 交雑 / 遺伝子浸透 / 生殖隔離 / 生殖隔離の強化

Outline of Final Research Achievements

To figure out the reinforcement of reproductive isolation in haplodiploidy, which has received little attention in speciation studies so far, I investigated the contact zone, genetic population structure in the contact zone, and reproductive isolation of two closely related species of Stigmaeopsis miscanthi species group. In the area where both species were found, they are distributed in high- and low-lands, respectively. We investigated their distributions at the intermediate altitude and found their contact zone. Sex ratios in their contact zone indicated that interspecific mating was taking place there, and cross experiments confirmed that they hybridize, although there is a strong postmating, prezygotic barrier. However, no hybrids were collected from their contact zone, and genetic introgression was negligible. Therefore, genetic introgression between them was restricted not only by postmating, prezygotic barrier but also by some other mechanisms.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

今日ある生物多様性を理解する上で種分化機構の解明は重要な研究課題の一つである。アリやハチといった人間とは異なる遺伝システムをもつ半倍数体は、最も種数の多い分類群といわれる節足動物のおよそ15%を占めるが、半倍数体を対象とした種分化研究は数少ない。半倍数体ハダニ近縁2種における接触帯の状況、接触帯での交雑状況を明らかにした本研究は、半倍数体の種分化研究の推進に大きく寄与するものである。