Shealy Ethan P, Schwartz Tonia S, Cox Robert M, Reedy Aaron M, Parrott Benjamin B
Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA.
Eugene P. Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
Sci Adv. 2025 Jan 31;11(5):eadq3589. doi: 10.1126/sciadv.adq3589.
Sex differences in life span are widespread across animal taxa, but their causes remain unresolved. Alterations to the epigenome are hypothesized to contribute to vertebrate aging, and DNA methylation-based aging clocks allow for quantitative estimation of biological aging trajectories. Here, we investigate the influence of age, sex, and their interaction on genome-wide DNA methylation patterns in the brown anole (), a lizard with pronounced female-biased survival and longevity. We develop a series of age predictor models and find that, contrary to our predictions, rates of epigenetic aging were not slower in female lizards. However, methylation states at loci acquiring age-associated changes appear to be more "youthful" in young females, suggesting that female DNA methylomes are preemptively fortified in early life in opposition to the direction of age-related drift. Collectively, our findings provide insights into epigenetic aging in reptiles and suggest that early-life epigenetic profiles may be more informative than rates of change for predicting sex biases in longevity.
寿命的性别差异在动物分类群中广泛存在，但其成因仍未得到解决。表观基因组的改变被认为与脊椎动物衰老有关，基于DNA甲基化的衰老时钟可以对生物衰老轨迹进行定量估计。在这里，我们研究了年龄、性别及其相互作用对棕色安乐蜥全基因组DNA甲基化模式的影响，棕色安乐蜥是一种雌性存活率和寿命明显偏高的蜥蜴。我们开发了一系列年龄预测模型，发现与我们的预测相反，雌性蜥蜴的表观遗传衰老速度并不慢。然而，在发生与年龄相关变化的位点上，年轻雌性蜥蜴的甲基化状态似乎更“年轻”，这表明雌性DNA甲基化组在生命早期就被预先强化，以对抗与年龄相关的漂移方向。总的来说，我们的研究结果为爬行动物的表观遗传衰老提供了见解，并表明早期的表观遗传特征在预测寿命的性别偏差方面可能比变化率更具信息价值。
