Department of Mouse Molecular Genetics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec 252 50, Czech Republic.
Department of Mouse Molecular Genetics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec 252 50, Czech Republic.
Trends Genet. 2021 Dec;37(12):1095-1108. doi: 10.1016/j.tig.2021.06.008. Epub 2021 Jul 5.
Hybrid sterility is a critical step in the evolution of reproductive barriers between diverging taxa during the process of speciation. Recent studies of young subspecies of the house mouse revealed a multigenic nature and frequent polymorphism of hybrid sterility genes as well as the recurrent engagement of the meiosis-specific gene PR domain-containing 9 (Prdm9) and X-linked loci. Prdm9-controlled hybrid sterility is essentially chromosomal in nature, conditioned by the sequence divergence between subspecies. Depending on the Prdm9 interallelic interactions and the X-linked Hstx2 locus, the same homologs either regularly recombine and synapse, or show impaired DNA DSB repair, asynapsis, and early meiotic arrest. Thus, Prdm9-dependent hybrid sterility points to incompatibilities affecting meiotic recombination as a possible mechanism of reproductive isolation between (sub)species.
杂种不育是物种形成过程中，分化类群之间生殖隔离进化的一个关键步骤。最近对小家鼠年轻亚种的研究揭示了杂种不育基因的多基因性质和频繁的多态性，以及减数分裂特异性基因 PR 结构域包含 9（Prdm9）和 X 连锁基因座的反复参与。Prdm9 控制的杂种不育本质上是染色体性的，由亚种间的序列差异决定。根据 Prdm9 等位基因间相互作用和 X 连锁 Hstx2 基因座，相同的同源物要么经常重组和联会，要么表现出 DNA DSB 修复受损、联会失败和早期减数分裂阻滞。因此，Prdm9 依赖性杂种不育表明，影响减数重组的不兼容性可能是（亚种）种间生殖隔离的一种机制。
