Institut des Sciences de l'Evolution de Montpellier, ISEM UMR 5554 (CNRS/Université Montpellier/IRD/EPHE), 34090 Montpellier, France.
School of Natural Sciences, University of Tasmania, Sandy Bay, TAS 7000, Australia.
Genes (Basel). 2021 Nov 8;12(11):1770. doi: 10.3390/genes12111770.
Therian mammals have among the oldest and most conserved sex-determining systems known to date. Any deviation from the standard XX/XY mammalian sex chromosome constitution usually leads to sterility or poor fertility, due to the high differentiation and specialization of the X and Y chromosomes. Nevertheless, a handful of rodents harbor so-called unusual sex-determining systems. While in some species, fertile XY females are found, some others have completely lost their Y chromosome. These atypical species have fascinated researchers for over 60 years, and constitute unique natural models for the study of fundamental processes involved in sex determination in mammals and vertebrates. In this article, we review current knowledge of these species, discuss their similarities and differences, and attempt to expose how the study of their exceptional sex-determining systems can further our understanding of general processes involved in sex chromosome and sex determination evolution.
真兽类哺乳动物拥有目前已知的最古老和最保守的性别决定系统。任何偏离标准 XX/XY 哺乳动物性染色体组成的情况通常会导致不育或生育能力低下，这是由于 X 和 Y 染色体的高度分化和专业化。然而，有少数啮齿动物具有所谓的不寻常性别决定系统。虽然在一些物种中发现了可育的 XY 雌性，但其他一些物种已经完全失去了 Y 染色体。这些非典型物种已经吸引了研究人员超过 60 年，它们构成了研究哺乳动物和脊椎动物性别决定中所涉及的基本过程的独特自然模型。在本文中，我们回顾了这些物种的现有知识，讨论了它们的相似之处和不同之处，并试图揭示研究它们异常性别决定系统如何进一步加深我们对性染色体和性别决定进化中所涉及的一般过程的理解。
