Rhen T, Sakata J T, Zeller M, Crews D
Section of Integrative Biology, School of Biological Sciences, University of Texas at Austin, 78712, USA.
Gen Comp Endocrinol. 2000 May;118(2):322-31. doi: 10.1006/gcen.2000.7477.
Incubation temperature during embryonic development determines gonadal sex in many reptiles, including the leopard gecko (Eublepharis macularius). In this study, we examined the hormonal and behavioral changes that occur during the reproductive cycle of female leopard geckos from four (i.e., 26, 30, 32.5, and 34 degrees C) incubation temperatures. Controlling for reproductive status, plasma levels of dihydrotestosterone (DHT), testosterone (T), and progesterone (P) varied with incubation temperature but estradiol 17-beta (E2) levels did not. Controlling for the effects of incubation temperature, DHT and T levels were low when females were previtellogenic, increased slightly during early vitellogenesis, increased dramatically during late vitellogenesis (i.e., prior to ovulation), and then decreased to previtellogenic levels after ovulation. In contrast, E2 levels increased gradually from the previtellogenic stage to the early vitellogenic stage, peaked during late vitellogenesis, and decreased to previtellogenic levels after ovulation. Levels of P increased from the previtellogenic stage to the early vitellogenic stage, remained elevated during late vitellogenesis, and then decreased after ovulation. Moreover, we determined that females were not sexually receptive when previtellogenic, were somewhat receptive during early vitellogenesis (approximately 20% receptive), were most receptive during late vitellogenesis (approximately 80% receptive), and were again unreceptive after ovulation. Incubation temperature did not influence receptivity. Overall, these data show that hormone levels and behavior change coordinately during the reproductive cycle. Although incubation temperature has persistent effects on endocrine physiology in adult female leopard geckos, these effects are modest compared to hormonal changes across the reproductive cycle.
在包括豹纹守宫（Eublepharis macularius）在内的许多爬行动物中，胚胎发育期间的孵化温度决定了性腺性别。在本研究中，我们研究了来自四种孵化温度（即26、30、32.5和34摄氏度）的雌性豹纹守宫在生殖周期中发生的激素和行为变化。在控制生殖状态的情况下，二氢睾酮（DHT）、睾酮（T）和孕酮（P）的血浆水平随孵化温度而变化，但雌二醇17-β（E2）水平则不然。在控制孵化温度的影响后，当雌性处于卵黄生成前期时，DHT和T水平较低，在卵黄生成早期略有升高，在卵黄生成后期（即排卵前）急剧升高，然后在排卵后降至卵黄生成前期水平。相比之下，E2水平从卵黄生成前期逐渐升高到卵黄生成早期，在卵黄生成后期达到峰值，排卵后降至卵黄生成前期水平。P水平从卵黄生成前期升高到卵黄生成早期，在卵黄生成后期保持升高，然后在排卵后下降。此外，我们确定雌性在卵黄生成前期没有性接受能力，在卵黄生成早期有一定的接受能力（约20%接受），在卵黄生成后期接受能力最强（约80%接受），排卵后再次没有接受能力。孵化温度不影响接受能力。总体而言，这些数据表明激素水平和行为在生殖周期中协同变化。尽管孵化温度对成年雌性豹纹守宫的内分泌生理有持续影响，但与整个生殖周期中的激素变化相比，这些影响较小。
