Tousignant A, Crews D
Department of Zoology, University of Texas, Austin 78712, USA.
J Morphol. 1995 May;224(2):159-70. doi: 10.1002/jmor.1052240205.
Temperature-dependent sex determination (TSD), in which the temperature at which an egg incubates determines the sex of the individual, occurs in egg-laying reptiles of three separate orders. Previous studies have shown that the embryonic environment can have effects lasting beyond the period of sex determination. We investigated the relative roles of incubation temperature, exogenous estradiol, and gonadal sex (testis vs. ovary) in the differentiation of adult morphological and physiological traits of the leopard gecko, Eublepharis macularius. The results indicate that incubation temperature, steroid hormones, and gonads interact in the development of morphological and physiological characters with incubation temperature resulting in the greatest differences in adult phenotype. Incubation temperature did not affect reproductive success directly, but may influence offspring survival in natural situations through effects on adult female body size. Postnatal hormones seem to be more influential in the formation of adult phenotypes than prenatal hormones. These results demonstrate that TSD species can be used to investigate the effects of the physical environment on development in individuals without a predetermined genetic sex and thus provide further insight into the roles of gonadal sex and the embryonic environment in sexual differentiation.
温度依赖型性别决定（TSD），即卵孵化时的温度决定个体的性别，发生在三个不同目下的卵生爬行动物中。先前的研究表明，胚胎环境的影响可能会持续到性别决定期之后。我们研究了孵化温度、外源性雌二醇和性腺性别（睾丸与卵巢）在豹纹守宫（Eublepharis macularius）成年形态和生理特征分化中的相对作用。结果表明，孵化温度、类固醇激素和性腺在形态和生理特征的发育过程中相互作用，其中孵化温度导致成年表型的差异最大。孵化温度并不直接影响繁殖成功率，但在自然环境中可能通过对成年雌性体型的影响来影响后代的生存。产后激素似乎比产前激素对成年表型的形成更具影响力。这些结果表明，TSD物种可用于研究物理环境对没有预定遗传性别的个体发育的影响，从而进一步深入了解性腺性别和胚胎环境在性别分化中的作用。
