Morphological analysis of the early development of telencephalic and diencephalic gonadotropin-releasing hormone neuronal systems in the enhanced green fluorescent protein-expressing transgenic medaka lines.
Morphological analysis of the early development of telencephalic and diencephalic gonadotropin-releasing hormone neuronal systems in the enhanced green fluorescent protein-expressing transgenic medaka lines.
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对表达增强型绿色荧光蛋白的转基因青鳉品系中端脑和间脑促性腺激素释放激素神经元系统早期发育的形态学分析。
作者：
Takahashi A;Islam MS;Abe H;Okubo K;Akazome Y;Kaneko T;Hioki H;*Oka Y.
硬骨鱼具有两个或三个促性腺激素释放激素（GnRH）基因的旁系同源物：gnrh 1，gnrh 2和gnrh 3。一些物种已经丢失了gnrh 1和/orgnrh 3基因，而gnrh 2在迄今为止分析的硬骨鱼物种中却完全保守。在大多数拥有GnRH 1的硬骨鱼中，GnRH 1肽是刺激促性腺激素释放的真正GnRH，而GnRH 2和GnRH 3（如果存在）则具有神经调节作用。GnRH 1和GnRH 3神经元的祖细胞起源于嗅板，并在早期发育过程中迁移到目的地。然而，由于识别GnRH 1或GnRH 3的通常可用的抗体的相对低的亲和力/特异性，这些神经元的标记仅可能使用遗传操作。我们使用了一个模型硬骨鱼，青，它拥有所有三个paralogousgnrh基因，前脑GnRH神经元组成的GnRH 1和GnRH 3神经元的发育进行了分析。在这里，我们新产生的转基因青鳉线，表达增强的绿色荧光蛋白的控制下的启动子forgnrh 1 orgnrh 3，检测GnRH神经元和促进免疫组织化学分析的神经元形态。我们使用免疫组织化学和三维共聚焦显微镜图像重建的组合，以更高的精度提高从GnRH 1或GnRH 3神经元群体中识别神经突的能力。这使我们能够清楚地确定垂体神经支配的GnRH 1神经元居住在腹侧视前区（vPOA）早在10天后孵化。此外，这些分析还揭示了vPOA中非促垂体性GnRH 1神经元的视网膜投射，在早期发育阶段突出，以及具有不同起源和迁移途径的GnRH 3神经元的多个群体。神经学比较杂志524：896-913，2016。© 2015 Wiley Periodicals，Inc.
Teleosts possess two or three paralogs of gonadotropin‐releasing hormone (GnRH) genes:gnrh1, gnrh2, andgnrh3. Some species have lost thegnrh1and/orgnrh3genes, whereasgnrh2has been completely conserved in the teleost species analyzed to date. In most teleosts that possessgnrh1, GnRH1 peptide is the authentic GnRH that stimulates gonadotropin release, whereas GnRH2 and GnRH3, if present, are neuromodulatory. Progenitors of GnRH1 and GnRH3 neurons originate from olfactory placodes and migrate to their destination during early development. However, because of the relatively low affinity/specificity of generally available antibodies that recognize GnRH1 or GnRH3, labeling of these neurons has only been possible using genetic manipulation. We used a model teleost, medaka, which possesses all three paralogousgnrhgenes, to analyze development of forebrain GnRH neurons composed of GnRH1 and GnRH3 neurons. Here, we newly generated transgenic medaka lines that express enhanced green fluorescent protein under the control of promoters forgnrh1orgnrh3, to detect GnRH neurons and facilitate immunohistochemical analysis of the neuronal morphology. We used a combination of immunohistochemistry and three‐dimensional confocal microscopy image reconstructions to improve identification of neurites from GnRH1 or GnRH3 neuronal populations with greater precision. This led us to clearly identify the hypophysiotropic innervation of GnRH1 neurons residing in the ventral preoptic area (vPOA) from as early as 10 days post hatching. Furthermore, these analyses also revealed retinopetal projections of nonhypophysiotropic GnRH1 neurons in vPOA, prominent during early developmental stages, and multiple populations of GnRH3 neurons with different origins and migratory pathways. J. Comp. Neurol. 524:896–913, 2016. © 2015 Wiley Periodicals, Inc.