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生长激素受体(GHR)作为GH/IGF轴的中心环节,在内分泌调控中发挥重要作用。本实验采用c DNA末端快速扩增法(RACE)技术克隆出花鲈GHR1和GHR2的c DNA全长序列。急性低盐度调控实验设为海水组、半海水组和淡水组。测定了急性低盐度调控24、48、96、144、192h后,花鲈肝脏中GHRs、IGF-1及垂体GH表达情况。结果表明,GHR1 c DNA全长序列2436bp,编码637个氨基酸;GHR2 c DNA全长序列2940bp,编码582个氨基酸。GHR1与GHR2由信号肽、胞外区、跨膜区、胞内区组成,且结构存在差异。脑、肾、鳃中GHR1表达明显高于GHR2;而在肌肉、垂体、肝脏、盲肠、胸腺、心脏中,GHR2表达明显高于GHR1。24h时,各组GHR1表达不变,GHR2、GH、IGF-1显著下降。之后,相对于海水组,淡水组和半海水组GHRs和IGF-1表达升高,而GH下降,GH与GHR负相关。据结果推测,花鲈GHR2可能为SL受体,GH/IGF轴参与低渗调控可能是通过增加GHRs,进而激活下游IGF-1表达而实现。
The growth hormone receptor (GHR) plays an important role in endocrine regulation as a central part of the GH / IGF axis. In this study, the c DNA full length sequence of GHR1 and GHR2 was cloned by rapid amplification of cDNA ends (RACE) technique. Acute low salinity regulation experiments were set as seawater group, semi-seawater group and freshwater group. The expression of GHRs, IGF-1 and pituitary GH in liver of perch were measured at 24, 48, 96, 144 and 192 h after acute low salinity regulation. The results showed that the full-length sequence of GHR1 c DNA was 2436 bp, encoding 637 amino acids. The full-length GHR2 c DNA sequence was 2940 bp, encoding 582 amino acids. GHR1 and GHR2 are composed of signal peptide, extracellular region, transmembrane region and intracellular region, and their structures are different. The expression of GHR1 in brain, kidney and gill was significantly higher than that in GHR2, while the expression of GHR2 in muscle, pituitary, liver, cecum, thymus and heart was significantly higher than that in GHR1.24h -1 significantly decreased. Afterwards, GHRs and IGF-1 levels were increased in freshwater and semi-seawater groups compared with those in seawater, while GH decreased and GH was negatively correlated with GHR. According to the results, GHR2 might be the SL receptor, and the hypothalamic regulation of GH / IGF axis may be through the increase of GHRs, and then the activation of downstream IGF-1 expression.