Faculty of Biosciences and AquacultureUniversity of Nordland, 8049 Bodø, NorwayDepartment of ZoologyFaculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-718 Olsztyn, Poland.
Faculty of Biosciences and AquacultureUniversity of Nordland, 8049 Bodø, NorwayDepartment of ZoologyFaculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-718 Olsztyn, PolandFaculty of Biosciences and AquacultureUniversity of Nordland, 8049 Bodø, NorwayDepartment of ZoologyFaculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-718 Olsztyn, Poland.
J Mol Endocrinol. 2014 Jun;52(3):357-71. doi: 10.1530/JME-13-0187. Epub 2014 Mar 19.
The role of sex steroid regulation in gonadal maturation is a very complex process that is far from being fully understood. Hence, we have investigated seasonal changes in gonadal expression of estrogen receptors (ERs) in Atlantic cod (Gadus morhua L.), a batch spawner, throughout the annual reproductive cycle. Three nuclear ER partial cDNA sequences (esr1, esr2a, and esr2b) were cloned and all esr transcripts were detected mainly in liver and gonads of fish of both sexes. In situ hybridization of esrs along with germ cell (vasa) and gonadal somatic cell markers (gonadal soma-derived factor (gsdf), 3β-hydroxysteroid dehydrogenase (3βhsd), and anti-Müllerian hormone (amh) for testicular, or gsdf for ovarian somatic cells) showed that all three esrs were preferentially localized within interstitial fibroblasts composed of immature and mature Leydig cells in testis, whereas they were differentially expressed in both follicular cells and oocytes in ovary. Quantitative real-time PCR analysis revealed a sexually dimorphic expression pattern of the three esr paralogs in testis and ovary. A significant increase in esr2a expression was identified in testis and of esr2b in ovary, whereas esr1 transcripts were elevated in both testis and ovary in February and March before the spawning period. The localization and sexually dimorphic expression of esr genes in gonads indicate a direct function of estrogen via ERs in gonadal somatic cell growth and differentiation for Leydig cell in testis and follicular cells in ovary throughout the annual reproductive cycle in Atlantic cod.
性类固醇调节在性腺成熟中的作用是一个非常复杂的过程，远未被完全理解。因此，我们研究了大西洋鳕鱼（Gadus morhua L.）的性腺雌激素受体（ERs）的季节性变化，大西洋鳕鱼是分批产卵的鱼类，其繁殖周期贯穿全年。克隆了三个核 ER 部分 cDNA 序列（esr1、esr2a 和 esr2b），并且所有 esr 转录本主要在鱼类的肝脏和性腺中被检测到。esrs 的原位杂交结合生殖细胞（vasa）和性腺体细胞标志物（睾丸的性腺体细胞衍生因子（gsdf）、3β-羟甾脱氢酶（3βhsd）和抗苗勒管激素（amh），或卵巢体细胞的 gsdf）显示，这三个 esr 都优先定位于睾丸中的间质成纤维细胞内，这些成纤维细胞由未成熟和成熟的莱迪希细胞组成，而在卵巢中，它们在卵泡细胞和卵母细胞中表达不同。实时定量 PCR 分析显示，这三个 esr 基因在睾丸和卵巢中的表达模式存在性别二态性。在繁殖期前的 2 月和 3 月，esr2a 在睾丸中的表达显著增加，esr2b 在卵巢中的表达增加，而 esr1 转录物在睾丸和卵巢中均升高。esr 基因在性腺中的定位和性别二态性表达表明，雌激素通过 ERs 在全年繁殖周期中直接作用于睾丸中的性腺体细胞生长和分化以及卵巢中的卵泡细胞。
