TEMPERATURE-DEPENDENT SEX DETERMINATION IN REPTILES - PROXIMATE MECHANISMS, ULTIMATE OUTCOMES, AND PRACTICAL APPLICATIONS
TEMPERATURE-DEPENDENT SEX DETERMINATION IN REPTILES - PROXIMATE MECHANISMS, ULTIMATE OUTCOMES, AND PRACTICAL APPLICATIONS
复制标题
DOI：
10.1002/dvg.1020150310
复制
发表时间：
1994-01-01
期刊：
影响因子：
--
通讯作者：
WIBBELS, T
中科院分区：
文献类型：
--
作者：
CREWS, D;BERGERON, JM;WIBBELS, T
在许多产卵的爬行动物中，卵的孵化温度决定了后代的性别，这一过程被称为温度依赖性性别决定（TSD）。在创伤后应激障碍中，性别决定是一个“要么全有，要么全无”的过程，很少形成双性人。温度的外部信号是如何转化为决定性腺性行为和性发育通道的遗传信号的？对红耳滑龟的研究主要集中在温度信号引发的生理、生化和分子级联反应上。雄性和雌性的发育都是主动的过程，而不是有基因型性别决定的脊椎动物的有组织/默认系统特征，这需要同时激活和抑制睾丸和卵巢决定级联来进行正常的性别决定。温度似乎通过作用于编码类固醇酶和类固醇激素受体的基因并改变胚胎内的内分泌微环境来实现这一目的。除了性别决定外，发育过程中所经历的温度也有长期的功能结果。对豹壁虎的研究表明，孵化温度和类固醇激素在形成成虫表型中起着组织者的作用，温度调节性激素在性别分化中的作用。最后，本研究在濒危产卵爬行动物的保护和恢复以及爬行动物胚胎发育作为生物标志物监测常见环境污染物的雌激素效应方面具有实际应用价值。(C) 1994 Wiley-Liss, Inc。
In many egg-laying reptiles, the incubation temperature of the egg determines the sex of the offspring, a process known as temperature-dependent sex determination (TSD). In TSD sex determination is an ''all or none'' process and intersexes are rarely formed. How is the external signal of temperature transduced into a genetic signal that determines gonadal sex and channels sexual development? Studies with the red-eared slider turtle have focused on the physiological, biochemical, and molecular cascades initiated by the temperature signal. Both male and female development are active processes-rather than the organized/default system characteristic of vertebrates with genotypic sex determination-that require simultaneous activation and suppression of testis- and ovary-determining cascades for normal sex determination. It appears that temperature accomplishes this end by acting on genes encoding for steroidogenic enzymes and steroid hormone accepters and modifying the endocrine microenvironment in the embryo. The temperature experienced in development also has long-term functional outcomes in addition to sex determination. Research with the leopard gecko indicates that incubation temperature as well as steroid hormones serve as organizers in shaping the adult phenotype, with temperature modulating sex hormone action in sexual differentiation. Finally, practical applications of this research have emerged for the conservation and restoration of endangered egg-laying reptiles as well as the embryonic development of reptiles as biomarkers to monitor the estrogenic effects of common environmental contaminants. (C) 1994 Wiley-Liss, Inc.