Gonadotropins (GtHs), including follicle‐stimulating hormone (FSH) and luteinizing hormone (LH), are important hormones involved in gametogenesis, gonadal steroidogenesis, and maturation. In this study, GtH subunits (FSHβ, LHβ and CGα) of largemouth bass (Micropterus salmoides) were cloned and characterized, and their regulation by luteinizing hormone‐releasing hormone analog (LHRHa2) and dopamine antagonist (DOM) treatment in vivo was investigated. The full‐length cDNA sequences of FSHβ, LHβ, and CGα were 683, 576, and 685bp, encoding 120, 152, and 132 amino acids, respectively. The deduced amino acid sequence analysis revealed that GtH subunits contain conserved cysteine residues and potential N‐linked glycosylation sites and showed high homology with the corresponding subunit sequences from other Perciformes by phylogenetic analysis. In the primary growth cortical alveoli stage of largemouth bass, the three GtH subunits were highly expressed in the pituitary, brain and ovary, but weakly in other tissues. After LHRHa2 and DOM injection, mRNA levels of FSHβ, LHβ, and CGα in the pituitary were significantly increased at 12 or 24 hr (p <.05), but significantly decreased at 48 hr; plasma FSH and LH levels showed a consistent trend. Histological analysis classified ovaries from LHRHa2‐ and DOM‐treated fish into the early oocyte maturation stage and late vitellogenesis stage, while those from the control group fish were classified into the early vitellogenesis stage. These results suggested that both LHRHa2 and DOM stimulated GtH subunit expression, increased plasma FSH and LH and accelerated ovary development of largemouth bass, providing a framework for a better understanding of the mechanisms of hormone‐mediated reproduction control in teleosts.

中文翻译：

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大嘴鲈（salmoides）的促性腺激素亚单位（fshβ，lhβ和cgα）的分子表征及其对黄体生成激素释放激素类似物和多巴胺拮抗剂的响应

促性腺激素（GtHs），包括促卵泡激素（FSH）和促黄体生成激素（LH），是参与配子发生，性腺类固醇生成和成熟的重要激素。在这项研究中，促性腺激素亚基鲈鱼（的（FSHβ，LHβ和CGα）加州鲈）进行克隆和表征，以及它们的调节由促黄体激素释放激素类似物（LHRHa2）和多巴胺拮抗剂（DOM）治疗在体内进行了研究。FSHβ，LHβ和CGα的全长cDNA序列为683、576和685bp，分别编码120、152和132个氨基酸。推导的氨基酸序列分析表明，GtH亚基含有保守的半胱氨酸残基和潜在的N。系统发育分析表明，该酶连接了糖基化位点，并与其他Performformes的相应亚基序列具有高度同源性 在大嘴鲈的初级生长皮质肺泡阶段，三个GtH亚基在垂体，脑和卵巢中高表达，而在其他组织中弱表达。LHRHa2和DOM注射后，垂体中FSHβ，LHβ和CGα的mRNA水平在12或24小时显着增加（p <.05），但在48小时时显着下降；血浆FSH和LH水平显示出一致的趋势。组织学分析将经LHRHa2和DOM处理的鱼的卵巢分为卵母细胞成熟早期和卵黄形成后期，而对照组鱼的卵巢则分为卵黄形成早期。这些结果表明LHRHa2和DOM都刺激GtH亚基表达，血浆FSH和LH增加以及大嘴鲈鱼卵巢发育加速，为更好地了解硬骨鱼中激素介导的生殖控制机制提供了框架。