Recent work has illuminated the bizarre sex chromosomal system of the mandarin vole, Lasiopodomys mandarinus. The ancestral sex chromosomes have been replaced by 4 neo-sex chromosomes. These sex chromosomes show non-Mendelian inheritance and epistatic sex determination, as well as unaccounted-for karyotype frequencies. I suggest a model to account for the complex observed inheritance patterns. The proposed model combines putative adaptations previously observed in rodents, including feminizing X chromosomes and Y-biased spermatogenesis, with a novel proposed mechanism of genomic imprinting of X-linked genes during oogenesis in XY females. Alternative possibilities are also discussed. The proposed scenario provides a relatively simple and testable model for the function and origins of a remarkably complex mammalian sex chromosomal system.

中文翻译：

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论鸳鸯奇异性染色体系统的形成与起源

最近的工作阐明了鸳鸯Lasiopodomys mandarinus奇异的性染色体系统。祖先的性染色体已被 4 条新性染色体取代。这些性染色体显示出非孟德尔遗传和上位性性别决定，以及无法解释的核型频率。我建议一个模型来解释观察到的复杂继承模式。所提出的模型结合了先前在啮齿动物中观察到的假定适应性，包括女性化 X 染色体和偏向 Y 的精子发生，以及在 XY 雌性卵子发生过程中 X 连锁基因的基因组印记的新提议机制。还讨论了替代的可能性。所提出的方案为非常复杂的哺乳动物性染色体系统的功能和起源提供了一个相对简单且可测试的模型。