中国美利奴绵羊肉用品系生长轴相关基因表达对其十二指肠发育的影响

Effects of Growth-Related Genes Expression on Duodenal Development in Chinese Merino Sheep(Meat Line)

本文旨在探讨生长轴基因与羔羊十二指肠生长发育的关系。分别于0、7、14、30、60和90日龄随机选取健康的中国美利奴绵羊(新疆军垦型)肉用品系雌、雄各3只,测定体质量后屠宰,迅速采集其脑垂体、肝脏和十二指肠等组织样品,并测量十二指肠长度。用荧光实时定量PCR法分别测定脑垂体中生长激素(GH)和生长激素释放激素受体(GHRHR),肝脏和十二指肠中生长激素受体(GHR)、胰岛素样生长因子1(IGF-1)和胰岛素样生长因子1受体(IGF-1R)基因表达的发育性变化,并进行了性别间比较。结果表明,羔羊肝脏中GHR基因和十二指肠中GHR、IGF-1基因表达mRNA丰度的变化模式与垂体中GH和GHRHR基因表达mRNA丰度的变化发育模式相似,呈先升高后逐渐下降的趋势,但这种趋势有一定的时差性;十二指肠的日增长发育性变化模式与肝脏中IGF-1基因表达的变化模式相似。结果提示,十二指肠的发育性变化主要受到肝脏中产生的IGF-1内分泌作用的调控,同时也可能受到脑垂体中GH内分泌的直接作用。

This experiment was conducted to study the effect of growth axis genes on growth performance of duodenum in Chinese Merino sheep（Xinjiang Junken type）.Chinese Merino sheep were weighed and the length of duodenum was measured at 0,7,14,30,60 and 90 days.Meanwhile,pituitary gland,liver and duodenum samples were collected.Real time PCR was applied to investigate the developmental expression patterns of GHR,IGF-l and IGF-lR genes in liver and duodenum as well as GH and GHRHR genes in pituitary gland of Chinese Merino lamb（Xinjiang Junken type）.Results showed that the expression patterns of GH and GHRHR genes in pituitary gland of lamb seemed to be similar to the expression of GHR genes in liver and duodenum,which increased and declined thereafter gradually.The developmental patterns of average daily length of duodenum gain and the expression pattern of IGF-1 mRNA were similar.These results indicated that the developmental regulation of duodenum was mainly affected by the expression of IGF-1 genes in liver and the expression of GH genes in pituitary gland.