School of Biological Sciences, Campus Box 4120, Illinois State University, Normal, IL 61790-4120, USA.
Gen Comp Endocrinol. 2012 May 1;176(3):507-12. doi: 10.1016/j.ygcen.2011.10.009. Epub 2011 Oct 18.
Eggs of oviparous amniotes can contain substantial quantities of several steroids at the time of oviposition. These maternally derived steroids appear to affect the phenotype of developing offspring, but not all steroid sensitive traits are affected by maternal steroids, and little is known about how these effects may arise. In this study, we applied tritiated estradiol to the eggs of red-eared sliders (Trachemys scripta) at the time of oviposition and characterized the subsequent metabolism and movement throughout embryonic development. Results indicate that very early in development, estradiol is converted to a variety of water-soluble estrogen sulfates that reside in the yolk and extraembryonic fluids until late in development. Within the final stages of development, we observe a significant decline in the total amount of metabolites present in the yolk and extraembryonic fluids and a significant increase in the amount of metabolites present in the embryo. While estradiol metabolism occurs during the early stages of development, the later stages appear to be the most dynamic with regards to the movement of estradiol metabolites. Our findings have important implications for studies investigating the effect of maternally derived steroids on offspring development.
卵生羊膜动物的卵在产卵时可以包含大量几种类固醇。这些母体来源的类固醇似乎影响发育后代的表型，但并非所有类固醇敏感特征都受母体类固醇影响，并且对于这些影响如何产生知之甚少。在这项研究中，我们在产卵时将氚标记的雌二醇应用于红耳龟（Trachemys scripta）的卵中，并描述了随后在胚胎发育过程中的代谢和移动。结果表明，在发育的早期，雌二醇就被转化为各种水溶性雌酮硫酸盐，这些硫酸盐存在于蛋黄和胚胎外液中，直到发育后期。在发育的最后阶段，我们观察到蛋黄和胚胎外液中存在的代谢物总量显着减少，而胚胎中存在的代谢物数量显着增加。虽然雌二醇代谢发生在发育的早期阶段，但后期阶段在雌二醇代谢物的移动方面似乎最为活跃。我们的研究结果对研究母体来源的类固醇对后代发育的影响具有重要意义。
