Sepers Bernice, Ruuskanen Suvi, van Mastrigt Tjomme, Mateman A Christa, van Oers Kees
Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, The Netherlands.
Mol Ecol. 2025 Feb;34(4):e17647. doi: 10.1111/mec.17647. Epub 2025 Jan 6.
Maternal hormones can profoundly impact offspring physiology and behaviour in sex-dependent ways. Yet little is known about the molecular mechanisms linking these maternal effects to offspring phenotypes. DNA methylation, an epigenetic mechanism, is suggested to facilitate maternal androgens' effects. To assess whether phenotypic changes induced by maternal androgens associate with DNA methylation changes, we experimentally manipulated yolk testosterone levels in wild great tit eggs (Parus major) and quantified phenotypic and DNA methylation changes in the hatched offspring. While we found no effect on the handing stress response, increased yolk testosterone levels decreased the begging probability, emphasised sex differences in fledging mass, and affected methylation at 763 CpG sites, but always in a sex-specific way. These sites are associated with genes involved in growth, oxidative stress, and reproduction, suggesting sex-specific trade-offs to balance the costs and benefits of exposure to high yolk testosterone levels. Future studies should assess if these effects extend beyond the nestling stage and impact fitness.
母体激素能够以性别依赖的方式深刻影响后代的生理和行为。然而，对于将这些母体效应与后代表型联系起来的分子机制，我们却知之甚少。DNA甲基化作为一种表观遗传机制，被认为有助于母体雄激素发挥作用。为了评估母体雄激素诱导的表型变化是否与DNA甲基化变化相关联，我们通过实验操纵了野生大山雀（Parus major）卵中的卵黄睾酮水平，并对孵化出的后代的表型和DNA甲基化变化进行了量化。虽然我们没有发现对处理应激反应有影响，但卵黄睾酮水平的升高降低了乞食概率，突出了 fledging 质量上的性别差异，并影响了763个CpG位点的甲基化，但总是以性别特异性的方式。这些位点与参与生长、氧化应激和繁殖的基因相关，这表明存在性别特异性的权衡，以平衡暴露于高卵黄睾酮水平的成本和收益。未来的研究应该评估这些影响是否超出雏鸟阶段并影响适应性。
