Parolini Marco, Possenti Cristina Daniela, Caprioli Manuela, Rubolini Diego, Romano Andrea, Saino Nicola
Physiol Biochem Zool. 2019 Sep/Oct;92(5):459-462. doi: 10.1086/705037.
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 () 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.
母体对卵成分的决定对后代有重大影响。母体卵雄激素根据后代性状和生命阶段具有多样且往往相反的作用，这表明母体在卵激素传递上面临权衡。然而，卵雄激素对胚胎端粒长度的影响（端粒长度是一个可能影响性能的主要性状）从未被研究过。我们给黄腿鸥（）的卵施用了生理剂量的睾酮（T），发现与对照组相比，孵化前不久肝脏中的端粒长度缩短，但大脑、心脏和胸肌中的端粒长度未受影响。端粒长度在不同体细胞组织中有所不同，并且与卵处理无关，它们之间不相关，这表明端粒动态是独立的。因此，我们首次表明卵中T增加会导致胚胎端粒缩短，并且母体T分配策略也可能因这种影响而进化。此外，与成年鸟类的观察结果相反，在胚胎阶段，一个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。
