Kisspeptin2 is a neuropeptide widely found in the brain and multiple peripheral tissues in the zebrafish. The pituitary is the center of synthesis and secretes various endocrine hormones. However, Kiss2 innervation in the zebrafish pituitary is unknown. In this study, the organization of Kiss2 cells and nerve fibers in the zebrafish pituitary by promoter-driving mCherry-labeling Kiss2 neurons were investigated. Kiss2 neurons in the hypothalamus do not project into the pituitary. Kiss2 cells and fibers are found in the female pituitary. Kiss2 neurons and projections are located in the proximal pars distalis (PPD), similar to the distribution of Gnrh3 fibers. Kiss2 structures reside alongside Gnrh3 fibers. No Kiss2 structures are found in the male pituitary. The transcriptional expression of the kisspeptin receptor kiss1rb is detected in both female and male pituitaries. In situ hybridization shows that kiss1rb-positive cells are located in the PPD and pars intermedia (PI). In vitro Kiss2-10 treatment stimulates Akt and Erk phosphorylation and significantly induces lhβ, fshβ, and prl1 mRNA expression in the female pituitary. The results in this study suggest that Kiss2 and Kiss1rb may form an independent paracrine or autocrine system in the female zebrafish pituitary. Kiss2 and Kiss1rb signaling regulates the expression of pituitary hormones.

中文翻译：

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Kisspeptin2调节雌性斑马鱼（Danio rerio）垂体中的激素表达。

Kisspeptin2是一种神经肽，广泛存在于大脑和斑马鱼的多个外周组织中。垂体是合成的中心，并分泌各种内分泌激素。然而，在斑马鱼垂体中的Kiss2神经支配是未知的。在这项研究中，研究了通过启动子驱动mCherry标记的Kiss2神经元在斑马鱼垂体中Kiss2细胞和神经纤维的组织。下丘脑中的Kiss2神经元不伸入垂体。在雌性垂体中发现Kiss2细胞和纤维。Kiss2神经元和突起位于远侧近端（PPD），类似于Gnrh3纤维的分布。Kiss2结构与Gnrh3纤维并存。在男性垂体中未发现Kiss2结构。在女性和男性垂体中都检测到kisepteptin受体kiss1rb的转录表达。原位杂交表明，kiss1rb阳性细胞位于PPD和pars intermedia（PI）中。体外Kiss2-10处理可刺激Akt和Erk磷酸化，并显着诱导雌性垂体中lhβ，fshβ和prl1 mRNA表达。这项研究的结果表明，Kiss2和Kiss1rb可能在雌性斑马鱼垂体中形成独立的旁分泌或自分泌系统。Kiss2和Kiss1rb信号传导调节垂体激素的表达。在女性垂体中Pr1和prl1 mRNA的表达。这项研究的结果表明Kiss2和Kiss1rb可能在雌性斑马鱼垂体中形成独立的旁分泌或自分泌系统。Kiss2和Kiss1rb信号传导调节垂体激素的表达。在女性垂体中Pr1和prl1 mRNA的表达。这项研究的结果表明，Kiss2和Kiss1rb可能在雌性斑马鱼垂体中形成独立的旁分泌或自分泌系统。Kiss2和Kiss1rb信号传导调节垂体激素的表达。