Rayner Jack G, Bock Samantha L, Lonski Andrew J, Riddle Nicole C, Wilkinson Gerald S
Department of Biology, University of Maryland College Park, College Park, Maryland, USA.
Kellogg Biological Station, Michigan State University, East Lansing, Michigan, USA.
Ann N Y Acad Sci. 2025 Aug 23. doi: 10.1111/nyas.70021.
Sex-biased longevity is observed across a wide range of animal taxa, including bats, for reasons not well understood. Patterns of cytosine methylation vary predictably with age in many organisms, offering a valuable means to investigate differences in patterns of aging at the molecular level. We tested sex differences in cytosine methylation across 14 bat species and compared patterns of age-associated variation. Sex differences were overrepresented on the X chromosome, showing a strong pattern of female hypermethylation within promoter regions. Sex- and age-associated differences in methylation were nonrandomly distributed with respect to proximity to putative sex hormone receptor binding sites, with sites hypermethylated in males and females tending to be underrepresented near androgen and estrogen receptor binding sites, respectively. Across species, we observed that the relative steepness of male versus female slopes of age-associated variation appeared to be associated with the strength of precopulatory sexual selection, with especially strong trends toward male-biased age-associated slopes in two harem-polygynous species that exhibit female-biased longevity. Our results offer insights into how patterns of methylation differ across sexes and ages, and raise intriguing questions for future research, such as whether sex differences in molecular aging reflect sex-biased longevity, for which records in bats are sparse.
在包括蝙蝠在内的广泛动物类群中都观察到了性别偏向的寿命差异，但其原因尚不清楚。在许多生物体中，胞嘧啶甲基化模式会随年龄发生可预测的变化，这为在分子水平上研究衰老模式的差异提供了一种有价值的方法。我们测试了14种蝙蝠的胞嘧啶甲基化性别差异，并比较了与年龄相关的变化模式。性别差异在X染色体上的表现更为突出，在启动子区域呈现出强烈的雌性高甲基化模式。甲基化的性别和年龄相关差异相对于假定的性激素受体结合位点的距离呈非随机分布，在雄性和雌性中高甲基化的位点分别在雄激素和雌激素受体结合位点附近较少出现。在不同物种中，我们观察到与年龄相关变化的雄性与雌性斜率的相对陡峭程度似乎与交配前性选择的强度有关，在表现出雌性偏向寿命的两种一夫多妻制物种中，尤其呈现出强烈的雄性偏向年龄相关斜率趋势。我们的研究结果为甲基化模式在性别和年龄上的差异提供了见解，并为未来的研究提出了有趣的问题，比如分子衰老中的性别差异是否反映了性别偏向的寿命差异，而蝙蝠在这方面的记录很少。
