卵形鲳鲹促性腺激素β亚基的克隆鉴定及其受雌二醇的调控

Cloning and characterization of gonadotropinβsubunit genes in pompano(Trachinotus ovatus)and their regulation by estradiol

促性腺激素(GtH,gonadotropin hormone)是垂体合成和分泌的一类重要糖蛋白激素,包括促卵泡生成素(Fsh,follicle stimulating hormone)和促黄体生成素(Lh,luteinizing hormone),在促进性腺发育和成熟过程中发挥重要作用。本研究成功克隆了卵形鲳鲹(Trachinotus ovatus)fshβ和lhβ基因的开放阅读框(ORF,open reading frame)序列,fshβORF长度为363 bp,lhβORF长度为447 bp。通过荧光定量PCR技术(qPCR,quantitative realtime PCR)检测,发现fshβ和lhβ基因在卵形鲳鲹的下丘脑-垂体-性腺轴(HPG,hypothalamus-pituitary-gonadal axis)显著表达,在垂体中的表达水平最高,其次是下丘脑和性腺。此外,通过体外实验评估17β-雌二醇(E2,17β-estradiol)对卵形鲳鲹垂体组织中fshβ和lhβ基因表达的影响。结果显示,10μmol/L E2处理6 h后,GtHβ亚基基因的表达被极显著抑制。最后,使用雌激素受体(ER,estrogen receptor)拮抗剂体外孵育卵形鲳鲹垂体组织,发现广谱性拮抗剂Fulvestrant、ERβ拮抗剂Cyclofenil和ERα拮抗剂MPP(MPP dihydrochloride)均能够消除E2对GtHβ亚基基因表达的抑制作用。综上所述,研究结果表明E2对卵形鲳鲹GtH的分泌具有负反馈调节作用,为卵形鲳鲹生殖调控机制提供了有价值的见解。

Gonadotropin hormones(GtH)are a crucial class of glycoprotein hormones synthesized and secreted by the pituitary,playing a pivotal role in promoting gonadal development and maturation.In this study,we successfully cloned the open reading frame(ORF)sequences of fshβand lhβfrom pompano(Trachinotus ovatus),with fshβORF length of 363 bp and lhβORF length of 447 bp.Using quantitative real-time PCR(qPCR),we observed expression of fshβand lhβin various tissues of pompano,with the highest levels detected in the pituitary followed by the hypothalamus.Furthermore,in vitro experiments were conducted to assess the effect of 17β-estradiol(E2)on fshβand lhβexpression in pompano pituitary.Results showed a significant inhibition of fshβand lhβexpression after 6 h of treatment with 10μmol/L E2.Lastly,using estrogen receptor(ER)antagonists for in vitro incubation of pompano pituitary tissue,we demonstrated that broad-spectrum antagonist Fulvestrant,ERβantagonist Cyclofenil,and ERαantagonist MPP dihydrochloride could alleviate the inhibitory effect of E2on fshβand lhβexpression.Overall,our findings suggest a negative feedback regulation of E2 on GtH secretion in pompano,providing valuable insights into the reproductive regulation mechanism of pompano.