在日本一個(gè)三刺魚(yú)種群（但并不是第二個(gè)與之密切相關(guān),、分享同一生境的物種）中一個(gè)新形成的性染色體系統(tǒng)的發(fā)現(xiàn)提供了這樣的證據(jù)：性染色體變化在引起生殖隔離和物種形成中所起作用可能要比以前所認(rèn)為的更大,。基因定位研究顯示,，新形成的X染色體包含雄性求偶行為基因,，而先祖X染色體既包含行為隔離基因，又包含雜交種雄性不育基因,。這些特征在該物種與在太平洋中發(fā)現(xiàn)的先祖形式之間構(gòu)成一個(gè)有效的生殖障礙,。（生物谷Bioon.com）
推薦閱讀：
Nature：干細(xì)胞中X染色體調(diào)控
Nature：Xist并不能引發(fā)X染色體失活
Genome Biology：X染色體存在轉(zhuǎn)錄噪音“補(bǔ)償”
生物谷推薦原始出處：
Nature 461, 1079-1083 (22 October 2009) | doi:10.1038/nature08441
A role for a neo-sex chromosome in stickleback speciation
Jun Kitano1,7, Joseph A. Ross1,2,7, Seiichi Mori3, Manabu Kume4, Felicity C. Jones5, Yingguang F. Chan5, Devin M. Absher6,7, Jane Grimwood6,7, Jeremy Schmutz6,7, Richard M. Myers6,7, David M. Kingsley5 & Catherine L. Peichel1
1 Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109, USA
2 Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, Washington 98195, USA
3 Biological Laboratory, Gifu-keizai University, Ogaki, Gifu 503-8550, Japan
4 Aqua Restoration Research Center, Public Works Research Institute, Kakamigahara, Gifu 501-6021, Japan
5 Department of Developmental Biology and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
6 Department of Genetics and Stanford Human Genome Center, Stanford University, Stanford, California 94304, USA
7 Present addresses: Department of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan (J.K.); Department of Biology, University of Maryland, College Park, Maryland 20742, USA (J.A.R.); HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
Correspondence to: Catherine L. Peichel1 Correspondence and requests for materials should be addressed to C.L.P.
Sexual antagonism, or conflict between the sexes, has been proposed as a driving force in both sex-chromosome turnover and speciation. Although closely related species often have different sex-chromosome systems, it is unknown whether sex-chromosome turnover contributes to the evolution of reproductive isolation between species. Here we show that a newly evolved sex chromosome contains genes that contribute to speciation in threespine stickleback fish (Gasterosteus aculeatus). We first identified a neo-sex chromosome system found only in one member of a sympatric species pair in Japan. We then performed genetic linkage mapping of male-specific traits important for reproductive isolation between the Japanese species pair. The neo-X chromosome contains loci for male courtship display traits that contribute to behavioural isolation, whereas the ancestral X chromosome contains loci for both behavioural isolation and hybrid male sterility. Our work not only provides strong evidence for a large X-effect on reproductive isolation in a vertebrate system, but also provides direct evidence that a young neo-X chromosome contributes to reproductive isolation between closely related species. Our data indicate that sex-chromosome turnover might have a greater role in speciation than was previously appreciated.
