Data from: Glucocorticoid metabolism in the in ovo environment modulates exposure to maternal corticosterone in Japanese quail embryos (Coturnix japonica)

Maternal effects have gained attention as a method by which mothers may alter the physiological condition and phenotype of their offspring based upon current environmental conditions. The physiological and phenotypic outcomes of glucocorticoid-mediated maternal effects have been extensively studied in a variety of vertebrates; however, the underlying mechanism is currently unclear. Here, we injected tritiated corticosterone into the yolks of developing Japanese quail eggs (Coturnix japonica) and traced its movement and metabolism through the in ovo development period. We found that corticosterone was extensively conjugated throughout the egg by the end of development, and while minimal corticosterone was detected within the embryo during development, accumulation of a conjugated metabolite in the embryo started to occur on day 6 of development. Because no movement and metabolism of corticosterone occurred in infertile eggs, our findings suggest that embryos are not passive recipients of maternal steroids, but instead appear to possess extensive metabolic capabilities, which may modulate their exposure to maternal steroids.

母体效应（Maternal effects）作为母亲可依据当前环境条件调控后代生理状态与表型的重要途径，已受到学界广泛关注。糖皮质激素介导的母体效应所引发的生理与表型变化，已在多种脊椎动物类群中得到深入探究，但其潜在机制目前仍不明确。本研究将氚标记皮质酮注射至发育中的日本鹌鹑（Coturnix japonica）卵黄内，追踪其在卵内发育全程的迁移与代谢过程。结果显示，至发育周期结束时，皮质酮已在整个卵内广泛发生结合代谢；尽管发育过程中胚胎内仅能检测到极微量的皮质酮，但结合态代谢产物在胚胎中的积累始于发育第6天。由于未受精卵中未出现皮质酮的迁移与代谢现象，本研究结果提示，胚胎并非母体类固醇激素的被动接收者，反而具备广泛的代谢能力，可调节自身暴露于母体类固醇激素的水平。