Data from: Co-adjustment of yolk antioxidants and androgens in birds

Mothers can shape the developmental trajectory of their offspring through the transmission of resources such as hormones, antioxidants or immunoglobulins. Over the last two decades, an abundant literature on maternal effects in birds has shown that several of these compounds (i.e. androgens, glucocorticoids and antioxidants) often influence the same offspring phenotypic traits (i.e. growth, immunity or oxidative stress levels), making interaction effects between egg components a likely scenario. However, the potential interactive effects of maternally transmitted compounds on offspring development and potential co-adjustment of these compounds within an egg are still poorly understood. Here, we report the results of an interspecific comparative analysis on birds' egg yolk composition (i.e. androgens and antioxidants) where we found that yolk carotenoid and vitamin E concentrations are positively associated, supporting the hypothesis that these two antioxidants act in synergy. The concentrations of vitamin E also increased with increasing concentrations of testosterone. This last result confirms the emerging idea that androgens and antioxidants are co-adjusted within eggs and that maternally transmitted antioxidants might limit the potential direct and indirect effects of prenatal exposure to high testosterone levels on oxidative stress.

母体可通过传递激素、抗氧化剂（antioxidants）或免疫球蛋白（immunoglobulins）等资源，塑造后代的发育轨迹。近二十年来，针对鸟类母源效应（maternal effects）的大量研究文献表明，此类化合物中的若干类（即雄激素（androgens）、糖皮质激素（glucocorticoids）与抗氧化剂）往往会对后代的同一表型性状（phenotypic traits，即生长、免疫功能或氧化应激水平（oxidative stress levels））产生影响，这使得卵内组分间的交互效应（interaction effects）成为一种潜在情形。然而，母体传递的化合物对后代发育的潜在交互效应，以及这些化合物在卵内的潜在协同调控机制，目前仍知之甚少。本研究通过对鸟类卵黄成分（即雄激素与抗氧化剂）开展种间比较分析（interspecific comparative analysis），发现卵黄类胡萝卜素（carotenoid）与维生素E（vitamin E）的浓度呈正相关，支持了这两种抗氧化剂具有协同作用的假说。此外，维生素E的浓度会随睾酮（testosterone）浓度的升高而升高。这一结果证实了一项新兴观点：卵内雄激素与抗氧化剂存在协同调控，且母体传递的抗氧化剂或许能够限制产前暴露于高睾酮环境所带来的直接与间接氧化应激影响。