Ontogenic development of three GnRH systems in the brain of a pleuronectiform fish, barfin flounder
Ontogenic development of three GnRH systems in the brain of a pleuronectiform fish, barfin flounder
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DOI：
10.2108/zsj.21.311
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发表时间：
2004-03-01
影响因子：
0.9
通讯作者：
Yamamori, K
中科院分区：
文献类型：
--
作者：
Amano, M;Okubo, K;Yamamori, K
一种鲽形目鱼类，即须鳍比目鱼Verasper moseri，在大脑中有三种分子形式的促性腺激素释放激素（GnRH），鲑鱼GnRH（sGnRH），鸡GnRH-II（cGnRH-II）和海鸟GnRH（sbGnRH）。为了阐明产生这些GnRH分子的神经元的个体发育起源，通过原位杂交和免疫细胞化学研究了三种GnRH系统的发育。表达sGnRH mRNA的神经元胞体首先在孵化后21天（第21天）的嗅上皮附近检测到，然后在第28天的嗅神经和嗅球之间的过渡区和终末神经节中检测到。第7天，在脑室附近的中脑被盖中首次发现表达cGnRH-II mRNA的神经元胞体。在第7天首次在脑中发现cGnRH-II免疫反应性（ir）纤维。第42天，在视前区首次检测到sbGnRH mRNA表达神经元胞体。sbGnRH-ir纤维定位于视前区-下丘脑，并形成一个独特的束投射到垂体的第70天的轴突。这些结果表明，三种形式的GnRH神经元有不同的胚胎起源在barfin比目鱼在其他鲈形鱼类，如罗非鱼Oreochromis尼罗和红海鸟真鲷。sGnRH、cGnRH-II和sbGnRH神经元分别来源于嗅基板、中脑被盖近脑室和视前区。
A pleuronectiform fish, the barfin flounder Verasper moseri, has three molecular forms of gonadotropin-releasing hormone (GnRH) in the brain, salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and seabream GnRH (sbGnRH). To elucidate the ontogenic origin of the neurons that produce these GnRH molecules, the development of three GnRH systems was examined by in situ hybridization and immunocytochemistry. Neuronal somata that express sGnRH mRNA were detected first in the vicinity of the olfactory epithelium 21 days after hatching (Day 21), and then in the transitional area between the olfactory nerve and olfactory bulb and the terminal nerve ganglion on Day 28. cGnRH-II mRNA-expressing neuronal somata were first identified in the midbrain tegmentum near the ventricle on Day 7. cGnRH-II-immunoreactive (ir) fibers were first found in the brain on Day 7. sbGnRH mRNA-expressing neuronal somata were first detected in the preoptic area on Day 42. sbGnRH-ir fibers were localized in the preoptic area-hypothalamus, and formed a distinctive bundle of axons projecting to the pituitary on Day 70. These results indicate that three forms of GnRH neurons have separate embryonic origins in the barfin flounder as in other perciform fish such as tilapia Oreochromis niloticus and red seabream Pagrus major. sGnRH, cGnRH-II and sbGnRH neurons derive from the olfactory placode, the midbrain tegmentum near the ventricle and the preoptic area, respectively.