Variation in developmental conditions can affect a variety of embryonic processes and shape a number of phenotypic characteristics that can affect offspring throughout their lives. This is particularly true of oviparous species where development typically occurs outside of the female, and studies have shown that traits such as survival and behavior can be altered by both temperature and exposure to steroid hormones during development. In species with temperature-dependent sex determination (TSD), the fate of gonadal development can be affected by temperature and by maternal estrogens present in the egg at oviposition and there is evidence that these factors can affect gene expression patterns. Here, we explore how thermal fluctuations and exposure to an estrogen metabolite, estrone sulfate, affect the expression of several genes known to be involved in sexual differentiation; Kdm6b, Dmrt1, Sox9, FoxL2, and Cyp19A1. We found that most of the genes responded to both temperature and estrone sulfate exposure, but that the responses to these factors was not identical in that estrone sulfate effects occur downstream of temperature effects. Our findings demonstrate that conjugated hormones such as estrone sulfate are capable of influencing temperature dependent pathways to potentially alter how embryos respond to temperature and highlight the importance of studying the interaction of maternal hormone and temperature effects.

This content is only available via PDF.

Article PDF first page preview

Article PDF first page preview