Lemaître Jean-François, Voituron Yann, Herpe Léa, Veyrunes Frédéric
Universite Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, Villeurbanne, France.
Universite Claude Bernard Lyon 1, CNRS, Ecole de l'aménagement durable des territoires (ENTPE), Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), UMR 5023, Villeurbanne F-69622, France.
Proc Natl Acad Sci U S A. 2025 Jan 7;122(1):e2412609121. doi: 10.1073/pnas.2412609121. Epub 2024 Dec 31.
A wave of studies has recently emphasized the influence of sex chromosomes on both lifespan and actuarial senescence patterns across vertebrates and invertebrates. Basically, the heterogametic sex (XY males in XX/XY systems or ZW females in ZW/ZZ systems) typically displays a lower lifespan and a steeper rate of actuarial senescence than the homogametic sex. However, whether these effects extend to the senescence patterns of other phenotypic traits or physiological functions is yet to be determined. Here, we investigated whether sex chromosomes modulate reproductive senescence using females from the African pygmy mouse (). This biological model exhibits an odd sex determining system with a third, feminizing sex chromosome, X*, resulting in three distinct female genotypes (XX, XX, or XY) that coexist in natural populations. We found that the rate of senescence in litter size at birth is much more pronounced in heterogametic XY females than in homogametic XX or XX females that may support the unguarded X or toxic Y hypotheses and can be directly linked to the complex and unique X*Y phenotype. A decrease in neonatal survival with mother's age has also been found, but this decline is not different between the three female genotypes.
最近一系列研究强调了性染色体对脊椎动物和无脊椎动物寿命及实际衰老模式的影响。基本上，异配性别（XX/XY系统中的XY雄性或ZW/ZZ系统中的ZW雌性）通常比同配性别具有更短的寿命和更快的实际衰老速率。然而，这些影响是否扩展到其他表型特征或生理功能的衰老模式尚待确定。在此，我们利用非洲侏儒小鼠的雌性个体研究了性染色体是否调节生殖衰老。这种生物学模型展现出一种奇特的性别决定系统，存在第三条具有雌性化作用的性染色体X*，导致三种不同的雌性基因型（XX、XX或XY）在自然种群中共存。我们发现，出生时窝仔数的衰老速率在异配性别的XY雌性中比在同配性别的XX或XX雌性中更为明显，这可能支持未受保护的X或有毒Y假说，并且可直接与复杂独特的X*Y表型相联系。还发现新生仔鼠的存活率随母体年龄下降，但这种下降在三种雌性基因型之间并无差异。
