Neo-sex chromosome evolution shapes sex-dependent asymmetrical introgression barrier.
Neo-sex chromosome evolution shapes sex-dependent asymmetrical introgression barrier.
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DOI：
10.1073/pnas.2119382119
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发表时间：
2022-05-10
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
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越来越多的人认识到，性染色体不仅是两性之间的战场，也是防止不同谱系之间渗入的长城。在这里，我们使用实验进化、全基因组重测序和理论建模来剖析性染色体的多方面作用，利用物种形成早期具有不同性染色体系统的果蝇姐妹物种对之间的杂交种群。我们的工作揭示了新性染色体进化在物种边界创造性别依赖的不对称渗入屏障中的复杂作用，我们展示了不同种群遗传力量如何协同作用，以解释整个基因组中观察到的渗入模式。性染色体在物种间生殖屏障的进化中起着特殊的作用。在这里，我们描述了在一个实验杂交群体中，新生性染色体在渗入模式中的相互冲突的作用。nasuta果蝇和albomicans果蝇是最近分化出来的完全可育的姐妹物种，它们具有不同的性染色体系统。在D. albomicans中，常染色体（Muller CD）与祖先的X染色体和Y染色体融合产生了新性染色体，而在D. nasuta中，Muller CD仍未融合。我们发现，在新性染色体上包含重叠反转的大块是阻止基因渗入的最强屏障。有趣的是，新性别染色体渗入屏障是不对称的和性别依赖的。雌性杂交种在Muller CD上表现出明显的嗜白螨偏渗（neo-X过量），而雄性杂交种则表现出过量（neo-X， D. nasuta Muller CD）基因型的杂种优势。我们利用群体遗传模型分析了性染色体驱动、新性染色体与未融合的Muller CD之间的异源性配对不亲和性、新y劣势和新x优势在雌性和雄性中产生所观察到的性染色体基因型中的相互作用。我们发现，在这个系统中，适度的neo-Y劣势和白纹d.m albomicans特异性减数分裂驱动需要观察到雌性特异性白纹d.m albomicans偏向性渐近，以及配对不相容和neo-X优势。总之，这对年轻物种之间的杂交群体揭示了新性别染色体在物种边界性别依赖的不对称渗入屏障中的多方面作用。
It is increasingly recognized that sex chromosomes are not only the battlegrounds between sexes but also the Great Walls fencing off introgression between diverging lineages. Here we dissect the multifaceted roles of sex chromosomes using experimental evolution, whole-genome resequencing, and theoretical modeling, taking advantage of hybrid populations between a Drosophila sister species pair in the early stage of speciation that have different sex chromosome systems. Our work sheds light onto the complex roles of neo-sex chromosome evolution in creating a sex-dependent asymmetrical introgression barrier at a species boundary, and we show how diverse population genetic forces act in concert to explain observed patterns of introgression across the genome. Sex chromosomes play a special role in the evolution of reproductive barriers between species. Here we describe conflicting roles of nascent sex chromosomes on patterns of introgression in an experimental hybrid swarm. Drosophila nasuta and Drosophila albomicans are recently diverged, fully fertile sister species that have different sex chromosome systems. The fusion between an autosome (Muller CD) with the ancestral X and Y gave rise to neo-sex chromosomes in D. albomicans, while Muller CD remains unfused in D. nasuta. We found that a large block containing overlapping inversions on the neo-sex chromosome stood out as the strongest barrier to introgression. Intriguingly, the neo-sex chromosome introgression barrier is asymmetrical and sex-dependent. Female hybrids showed significant D. albomicans–biased introgression on Muller CD (neo-X excess), while males showed heterosis with excessive (neo-X, D. nasuta Muller CD) genotypes. We used a population genetic model to dissect the interplay of sex chromosome drive, heterospecific pairing incompatibility between the neo-sex chromosomes and unfused Muller CD, neo-Y disadvantage, and neo-X advantage in generating the observed sex chromosome genotypes in females and males. We show that moderate neo-Y disadvantage and D. albomicans specific meiotic drive are required to observe female-specific D. albomicans–biased introgression in this system, together with pairing incompatibility and neo-X advantage. In conclusion, this hybrid swarm between a young species pair sheds light onto the multifaceted roles of neo-sex chromosomes in a sex-dependent asymmetrical introgression barrier at a species boundary.
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影响因子：
4.1
作者：
INOUE, Y;KITAGAWA, O
通讯作者：
KITAGAWA, O
影响因子：
1.5
作者：
Bachtrog, Doris
通讯作者：
Bachtrog, Doris
影响因子：
3.3
作者：
CHANG, HY;AYALA, FJ
通讯作者：
AYALA, FJ
影响因子：
9.8
作者：
Masly, John P.;Presgraves, Daven C.
通讯作者：
Presgraves, Daven C.
影响因子：
64.8
作者：
通讯作者：
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