鸭发育早期下丘脑-垂体生长轴相关基因mRNA的表达特异性分析

The Profiles of Related Genes mRNA Expression in Duck Hypothalamus-Pituitary Growth Axis During Early Development

【目的】选择生长速度不同的高邮鸭和金定鸭为试验模型,3种不同品种鸭胚胎期和出雏早期下丘脑垂体生长轴相关基因的表达规律及其与体重和肝重的相关性。【方法】采用实时荧光定量PCR方法研究鸭13、17、21、25、27胚龄和出雏后7日龄下丘脑生长激素释放激素(growth hormone release hormone,GHRH)与生长抑素(somatostatin,SS)、垂体生长激素(growth hormone,GH)和肝脏生长激素受体(growth hormone receptor,GHR)与胰岛素样生长因子(insulin-like growth factors,IGFs)mRNA的表达规律。【结果】证实鸭下丘脑GHRH与SS、垂体GH和肝脏GHR与IGF-I在13胚龄已有表达;除了SS在鸭发育早期维持一个低表达状态外,其它的4种基因均呈现极显著的品种和时间特异性;除了GH外,发现鸭早期发育过程中GHRH、GHR和IGF-I mRNA的表达受到品种和日龄的交互作用的极显著影响。与鸡以往的研究相比,禽类胚胎期下丘脑垂体生长轴相关基因mRNA的表达存在着种属差异。本试验发现鸭早期发育过程中,体重和肝重的变化也呈现极显著的品种和时间特异性,且与下丘脑垂体相关基因的表达呈现不同程度的线性相关。【结论】结果提示下丘脑垂体生长轴基因mRNA的表达可能在鸭早期发育过程中发挥着重要作用,遗传背景的差异可以导致鸭发育早期体重的差异生长和相关基因的差异表达。

[ Objective ] The present experiment was conducted to study the tissue expression characteristics of related genes mRNA expression in duck hypothalamus-pituitary growth axis during embryogenesis and post-hatching development in different breeds of ducks. [ Method] We have compared the ontogeny of body weight and expression of growth hormone release hormone （GHRH）, somatostatin （SS）, growth hormone （GH）, growth hormone receptor （GHR）, insulin-like growth factor-I （IGF-I） mRNA on the embryonic day 13, 17, 21, 25, and 27 and the 7-day-old Gaoyou duck and Jinding duck. [Result] At the first time, the trial presented that duck hypothalamic GHRH and SS, pituitary GH, liver GHR and IGF- I mRNA were detected at El3. Except SS maintained a lower expression status in the duck early development, the other four genes showed a extremely significant difference in variety and time. In addition to GH, duck GHRH, GHR and IGF-I mRNA expression were significantly affected by breed and age interaction during early development. Compared with previous studies on chicken, significant species differences were observed in poultry embryonic hypothalamus-pituitary growth axis related gene mRNA expression. During early development, extremely significant variety and time specificity was found in developmental change of body and liver weight, and varying degrees of linearcorrelation was showed between that and related genes mRNA expression in duck hypothalamus-pituitary growth axis. [Conclusion] It was suggested that different genetic backgrounds may lead to the differential growth rate and the related gene differential expression, and the differential expression of related genes mRNA in duck hypothalamus-pituitary growth axis may be involved in the early growth of ducks.