Differential expression of three estrogen receptors mRNAs in tissues, growth development, embryogenesis and gametogenesis from large yellow croaker, Larimichthys crocea

作者：Chen, Shihai; Pu, Lulu; Xie, Fangjing; Zou, Zhihua; Jiang, Yonghua; Han, Kunhuang; Wang, Yilei^*; Zhang, Ziping

来源：General and Comparative Endocrinology, 2015, 216: 134-151.

DOI：10.1016/j.ygcen.2015.04.005

• Estrogen receptor
• Growth development
• Embryogenesis
• Gametogenesis
• In situ hybridization
• Larimichthys crocea

The biological activity of estrogens in target organs is mainly mediated by estrogen receptors (ERs). Herein, we addressed the isolation and expression analysis of three nuclear estrogen receptors, namely LcER alpha, LcER beta 1, and LcER beta 2 from Larimichthys crocea by means of SMART-RACE, qRT-PCR, and in situ hybridization. Results in different tissues showed that both LcER alpha and LcER beta 2 had the highest expression levels in female liver, followed by testis, but LcER beta 1 expression level was significantly higher in testis and ovary than in other tissues. Expression of LcER alpha and LcER beta 2 was significantly higher than LcER beta 1 in female liver, and LcER beta 2 was significantly higher than LcER alpha and LcER beta 1 in male liver. Moreover, we analyzed the expression of LcERs in gonad and liver at three different growth stages during the same breeding season. Significant up-regulated expression of LcER alpha and LcER beta 2 were found in female liver at 1000 dph compared with at 270 dph. The expression of LcER beta 2 was prominently higher in male liver than LcER alpha, LcER beta 1 and LcAR, while LcER beta 1 was lower than other receptors in male and female liver at all the three stages. In ovary, LcER alpha at 270 dph was lower than at 635 dph and 1000 dph, but had no significant change in testis. The two LcER beta subtypes and LcAR highly expressed in the early testis, and gradually decrease with the development of testis. In embryogenesis, a significant increase in the expression of LcER alpha and LcER beta 2 were observed after appearance of optic vesicles phase (11.8 hpf). LcER beta 1 gradually decrease with the embryogenesis but increased dramatically at 1dph. Results of in situ hybridization showed that signals of LcER alpha and LcER beta 1 mRNA were mainly detected in Stage I-Stage IV oocytes, as well as in follicle cells around the Stage II-Stage IV and degenerated oocytes. Signals of LcER beta 2 were detected in the cytoplasm of Stage I and Stage II oocytes but not in the follicle cells of all oocytes stages. In parallel, LcER alpha and LcER beta 1 were detected in all cell types of spermatogenesis, but in terms of LcER beta 2, little or no signals were detected during spermatogenesis. Based on these results, we deduced that both LcER alpha and LcER beta 2 play a major role in mediating the physiological effects of estrogen in female liver, and LcER beta 2 maybe also play an important role in regulation of vitellogenesis in male liver. Differential expression of LcERs and LcAR imply their physiological functions during development and differentiation of gonad. The signals for LcER alpha and LcER beta 1 in follicle cells suggested that the follicle cell maybe an important site of estrogen action, by which estrogens exert influences on the maturation oocytes and ovulation. Furthermore, the steroid hormones produced by follicle cells may be related to the differential distributions among ER subtypes. Besides, we deduced that LcER alpha and LcER beta 1 rather than LcER beta 2 may play a major role in spermatogenesis of croaker. However, the differential expression of LcER beta 2 during gametogenesis also implicates its certain functions in mediating physiological process of estrogen action.

• 出版日期2015-5-15
• 单位集美大学