Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system
Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system
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DOI：
10.1016/j.ygcen.2007.10.003
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发表时间：
2008-03-01
影响因子：
2.7
通讯作者：
Tsutsui, Kazuyoshi
中科院分区：
文献类型：
--
作者：
Bentley, George E.;Ubuka, Takayoshi;Tsutsui, Kazuyoshi
许多被归类为神经肽的激素除了在脑部外，还在脊椎动物的性腺中合成。这些激素的受体也在性腺组织中表达；因此，这些激素可能对各种性腺功能产生高度局部的自分泌或旁分泌效应。在目前的研究中，我们专注于促性腺激素抑制激素(GnIH)，这是一种最先在鸟类下丘脑中发现的神经肽。通过对雀形目和雀形目鸟类的研究，我们提出了鸟类生殖系统中GnIH及其受体合成的不同证据，包括性腺和附属生殖器官。通过体内和体外受体荧光摄影初步确定了GnIH的结合部位，并定位于卵巢颗粒细胞以及睾丸间质层和生精小管。此外，种属特异的引物还在鸣禽和鸣禽的性腺以及输卵管、附睾管和输精管等生殖组织中扩增出清晰的GnIH和GnIH受体(GnIH-R)。对聚合酶链式反应产物进行测序，确认了它们的身份。免疫细胞化学检测到GnIH多肽位于卵巢膜和颗粒细胞、睾丸间质细胞和生殖细胞以及附睾假复层柱状上皮细胞中。GnIH-R mRNA在睾丸组织中原位杂交产生强阳性反应产物，定位于生殖细胞和间质。在附精中，该产物也定位于假复层柱状上皮细胞。综上所述，这些结果表明，鸟类生殖系统具有合成和结合多种组织中的GnIH的能力。GnIH及其受体的分布提示，自分泌/旁分泌对性腺类固醇的产生和生殖细胞的分化和成熟具有潜在的调节作用。(C)2007 Elsevier Inc.保留所有权利。
Many hormones that are classified as neuropeptides are synthesized in vertebrate gonads in addition to the brain. Receptors for these hormones are also expressed in gonadal tissue; thus there is potential for a highly localized autocrine or paracrine effect of these hormones on a variety of gonadal functions. In the present study we focused on gonadotropin-inhibitory hormone (GnIH), a neuropeptide that was first discovered in the hypothalamus of birds. We present different lines of evidence for the synthesis of GnIH and its receptor in the avian reproductive system including gonads and accessory reproductive organs by studies on two orders of birds: Passeriformes and Cialliformes. Binding sites for GnIH were initially identified via in vivo and in vitro receptor fluorography, and were localized in ovarian granulosa cells along with the interstitial layer and seminiferous tubules of the testis. Furthermore, species-specific primers produced clear PCR products of GnIH and GnIH receptor (GnIH-R) in songbird and quail gonadal and other reproductive tissues, such as oviduct, epididymis and vas deferens. Sequencing of the PCR products confirmed their identities. Immunocytochemistry detected GnIH peptide in ovarian thecal and granulosa cells, testicular interstitial cells and germ cells and pseudo stratified columnar epithelial cells in the epididymis. In situ hybridization of GnIH-R mRNA in testes produced a strong reaction product which was localized to the germ cells and interstitium. In the epididymis, the product was also localized in the pseudostratified columnar epithelial cells. In sum, these results indicate that the avian reproductive system has the capability to synthesize and bind GnIH in several tissues. The distribution of GnIH and its receptor suggest a potential for autocrine/paracrine regulation of gonadal steroid production and germ cell differentiation and maturation. (C) 2007 Elsevier Inc. All rights reserved.