Maternal decisions on egg composition have major consequences for offspring. Maternal egg androgens have diverse, often contrasting, effects depending on offspring trait and life stage, suggesting that mothers face trade-offs in egg hormone transfer. However, the effect of egg androgens on embryonic telomere length, which is a major trait potentially affecting performance, has been never investigated. We administered a physiological dose of testosterone (T) to yellow-legged gull (Larus michahellis) eggs and found that, compared to controls, telomere length shortly before hatching was reduced in the liver but unaffected in the brain, heart, and pectoralis muscle. Telomere length varied across somatic tissues, and, independent of egg treatment, it was not correlated between them, suggesting independent telomere dynamics. Thus, we showed for the first time that increased egg T can increase telomere shortening in the embryo and that maternal T allocation strategies may evolve also in response to such effect. Moreover, contrary to observations in adult birds, at the embryonic stage telomere length in one somatic tissue may not reflect telomere length in other body districts.

中文翻译：

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卵睾丸激素对黄色腿鸥胚胎体细胞组织中端粒长度的影响不同。

产妇对鸡蛋成分的决定会对后代产生重大影响。产妇卵雄激素的作用取决于后代的性状和生命阶段，通常具有不同的对比作用，这表明母亲在卵激素的转移中需要权衡取舍。但是，从未研究过卵雄激素对胚胎端粒长度的影响，而端粒长度是可能影响性能的主要特征。我们对黄腿鸥（Larus michahellis）卵施用了生理剂量的睾丸激素（T），发现与对照组相比，肝脏孵化前不久的端粒长度减少了，但对脑，心脏和胸大肌却没有影响。端粒长度在体细胞组织中各不相同，并且与卵处理无关，它们之间没有相关性，表明端粒的动力学独立。从而，我们首次表明增加的卵T可以增加胚胎中端粒的缩短，而母体T的分配策略也可能针对这种效应而发展。此外，与成年鸟类的观察相反，在胚胎期，一种体细胞组织中的端粒长度可能无法反映其他身体部位的端粒长度。