Keais Graeme L, Saad-Roy Chadi M, Gonzalez-Sqalli Emmanuel, Powell Candice N, Rieseberg Loren H, Gawryluk Ryan M R, van den Driessche P, Wei Kevin H-C, Loppin Benjamin, Perlman Steve J
Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Proc Natl Acad Sci U S A. 2025 Apr 29;122(17):e2421185122. doi: 10.1073/pnas.2421185122. Epub 2025 Apr 23.
Meiotic drivers are selfish genetic elements that bias their own transmission during meiosis or gamete formation. Due to the fundamental differences between male and female meiosis in animals and plants, meiotic drivers operate through distinct mechanisms in the two sexes: In females, they exploit the asymmetry of meiosis to ensure their inclusion in the egg, whereas in males, they eliminate competing gametes after symmetric meiosis. Meiotic drive is commonly reported in males, where it strongly influences the evolution of spermatogenesis, while the few known cases in females have highlighted its crucial role in centromere evolution. Despite a growing number of examples in a wide range of organisms, meiotic drive has so far only been observed in one sex or the other since its discovery nearly 100 y ago. Here, we show that a selfish X chromosome known to cause meiotic drive in male flies also causes meiotic drive in females. We find that this X chromosome has supergene architecture, harboring extensive structural rearrangements that suppress recombination between the two X chromosomes. This has contributed to a substantial expansion of its size compared to the wild-type chromosome, partly due to the accumulation of species-specific repetitive elements. Our findings suggest that female meiotic drive may play an important role in the evolutionary dynamics of polymorphic structural variants that suppress recombination, including inversions, translocations, and supergenes.
减数分裂驱动因子是自私的遗传元件，在减数分裂或配子形成过程中偏向自身的传递。由于动植物雌雄减数分裂存在根本差异，减数分裂驱动因子在两性中通过不同机制发挥作用：在雌性中，它们利用减数分裂的不对称性确保自身进入卵子；而在雄性中，它们在对称减数分裂后消除竞争配子。减数分裂驱动在雄性中普遍存在，对精子发生的进化有强烈影响，而雌性中已知的少数案例突出了其在着丝粒进化中的关键作用。尽管在广泛的生物体中有越来越多的例子，但自近100年前发现减数分裂驱动以来，到目前为止只在一种性别中观察到。在这里，我们表明，已知在雄性果蝇中导致减数分裂驱动的一条自私X染色体在雌性中也会导致减数分裂驱动。我们发现这条X染色体具有超基因结构，含有广泛的结构重排，抑制两条X染色体之间的重组。这导致其大小与野生型染色体相比大幅增加，部分原因是物种特异性重复元件的积累。我们的研究结果表明，雌性减数分裂驱动可能在抑制重组的多态结构变异（包括倒位、易位和超基因）的进化动态中发挥重要作用。
