Gonadotropin-releasing hormone neuronal development during the sensitive period of temperature sex determination in the pejerrey fish, Odontesthes bonariensis
Gonadotropin-releasing hormone neuronal development during the sensitive period of temperature sex determination in the pejerrey fish, Odontesthes bonariensis
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DOI：
10.1016/s0016-6480(03)00117-5
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发表时间：
2003-07-01
影响因子：
2.7
通讯作者：
Somoza, GM
中科院分区：
文献类型：
--
作者：
Miranda, LA;Strobl-Mazzulla, PH;Somoza, GM
本文研究了南美银汉鱼（Odontesthesbonariensis）促性腺激素释放激素（GnRH）神经元的发育与热不稳定性性别决定敏感期的关系。在三种不同的温度下孵化：17摄氏度（100%雌性），24摄氏度（70%雌性）和29摄氏度（100%雄性）。在终末神经节（TNG）、中脑被盖（NIT）和视前区（POA）发现三组GnRH免疫反应阳性神经元。免疫反应性GnRH（ir-GnRH）神经元在孵化时（第0天）和在NIT在第3天在所有的实验温度。在POA中，分别在29、24和17 degreesC下饲养的幼虫的视前脑室周围核中鉴定出ir-GnRH神经元，同时在第11、14和17天的垂体中首次出现ir-GnRH纤维。TNG中ir-GnRH神经元的数量在温度之间没有显示任何统计学差异。在17 ℃和24 ℃的实验期间，NIT中的ir-GnRH神经元数量增加，而在29 ℃的实验期间，NIT中的ir-GnRH神经元数量减少。在POA的ir-GnRH神经元的数量增加，在发展过程中的峰值在第28天的所有温度的研究和这个峰值的幅度显示出与孵育温度的相关性。这些结果加强了下丘脑-垂体-性腺轴在pejerrey性别决定过程中活跃的概念，表明中枢神经系统和GnRH在此过程中可能发挥作用。本研究还提示，在温度敏感期，视前区的GnRH神经元可能是温度的生理传感器。(C)2003 Elsevier Science（美国）。All rights reserved.
The development of gonadotroping-releasing hormone (GnRH) neurons was studied in relation to the sensitive period of thermolabile sex determination in the pejerrey Odontesthes bonariensis, an atherinid fish from South America. Fish were raised from hatching at three different temperatures: 17degreesC (100% females), 24degreesC (70% females), and 29degreesC (100% males). Three groups of immunoreactive GnRH (ir-GnRH) neurons were identified at the terminal nerve ganglion (TNG), the midbrain tegmentum (NIT), and the preoptic area (POA). Immunoreactive GnRH (ir-GnRH) neurons were identified in the TNG at hatching (day 0) and in the NIT at day 3 at all the experimental temperatures. In the POA ir-GnRH neurons were identified in the nucleus preopticus periventricularis simultaneously with the first appearance of ir-GnRH fibers in the pituitary on days 11, 14, and 17 for larvae kept at 29, 24, and 17degreesC, respectively. The number of ir-GnRH neurons in the TNG did not show any statistical difference between temperatures. The number of ir-GnRH neurons in the NIT increased in number during the experiment for larvae kept at 17 and 24degreesC but decreased between days 17 and 31 in larvae kept at 29degreesC. The number of ir-GnRH neurons in the POA increased during development with a peak at day 28 for all temperatures studied and the magnitude of this peak showed a correlation with incubation temperature. These results reinforce the notion that the hypothalamus-pituitary-gonadal axis is active during sex determination in pejerrey suggesting a possible role of the central nervous system and GnRH in this process. It is also suggested that GnRH neurons located in the preoptic area might be the physiological transducers of temperature during the temperature sensitive period in this species. (C) 2003 Elsevier Science (USA). All rights reserved.