The Roles of the Kisspeptin System in the Reproductive Physiology of the Lined Seahorse (Hippocampus erectus), an Ovoviviparous Fish With Male Pregnancy
The Roles of the Kisspeptin System in the Reproductive Physiology of the Lined Seahorse (Hippocampus erectus), an Ovoviviparous Fish With Male Pregnancy
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DOI：
10.3389/fnins.2018.00940
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发表时间：
2018-12
影响因子：
4.3
通讯作者：
Huixian Zhang;Bo Zhang;G. Qin;Shuisheng Li;Q. Lin
中科院分区：
文献类型：
--
作者：
Huixian Zhang;Bo Zhang;G. Qin;Shuisheng Li;Q. Lin
Kispeptin/GPr54系统在脊椎动物生殖轴的调节中起着至关重要的作用。雄性怀孕和卵胎产是脊椎动物特有的生殖现象。为了更好地了解雄性妊娠的神经内分泌机制，从雄性妊娠的卵胎生性硬骨鱼--海马直立体中克隆了编码kiss2和GPR54的cDNAs，并对其进行了功能鉴定。海马Kiss2的核心成熟肽在海马中高度保守，但在脊椎动物Kiss同源物中是独一无二的。在系统发育分析中，海马吻与硬骨鱼Kiss2分支聚在一起。Kiss2转录本在不同组织中广泛表达，特别是在脑和性腺中，而Gpr54-2mRNA仅在脑中表达。此外，在雄性海马脑组织中发现的Kiss2 mRNA在青春期早期显著增加，在怀孕期间显著下降。性成熟雄性海马经腹腔注射海马KIS2-10，可刺激促黄体生成素(Lhβ，β)和卵泡刺激素(Fhβ，β)释放，提高血清睾酮水平。综上所述，我们首次在雄性妊娠的卵胎生鱼类中发现了Kisspeptin/GPr54系统，该系统可能通过调节促性腺激素(GTH)和睾酮的合成来调节青春期开始、性腺发育和雄性怀孕的生殖功能。
The kisspeptin/GPR54 system plays a crucial role in the regulation of the reproductive axis in vertebrates. Male pregnancy and ovoviviparity are special reproductive phenomena among vertebrates. To better understand the neuroendocrine mechanisms of male pregnancy, cDNAs encoding kiss2 and GPR54 were cloned and functionally characterized from the lined seahorse, Hippocampus erectus, an ovoviviparous teleost with male pregnancy. The core mature peptide of seahorse Kiss2 is high conserved among seahorses, but unique among vertebrate Kiss orthologs. In the phylogenic analysis, the seahorse Kiss clustered with the teleost Kiss2 clade. The kiss2 transcripts were shown to be widely expressed in various tissues, notably in the brain and gonad of the seahorse, while GPR54-2 mRNA was expressed exclusively in the brain. In addition, kiss2 mRNA found in male seahorse brain tissue increased significantly at the early pubertal stage, and decreased significantly during pregnancy. Intraperitoneal administration of seahorse Kiss2-10 to sexual mature male seahorses demonstrated to stimulate lutropin β (LHβ) and follitropin β (FSHβ) release and increased serum testosterone levels. In summary, we first identified the kisspeptin/GPR54 system in an ovoviviparous fish with male pregnancy, which might be involved in the regulation of the reproductive functions of pubertal onset, gonadal development, and male pregnancy via regulating the synthesis of both gonadotropic hormone (GTH) and testosterone.