Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, PR China.
Comp Biochem Physiol B Biochem Mol Biol. 2013 Aug;165(4):260-70. doi: 10.1016/j.cbpb.2013.05.006. Epub 2013 May 28.
The present study was designed to investigate the ontogeny and tissue distribution of somatostatin and its five receptor subtypes (SSTR1-5) mRNA expression in embryonic chicken (Gallus gallus). Brain, gonads (male), intestine, kidney, liver, muscle, stomach and yolk sac membrane (YSM) of chicken embryos on the embryonic (E) ages of 10, 16 and 21days (right before hatch) were investigated. Bisulfite sequencing PCR (BSP) was performed to determine the methylation status of the promoter region of all the six genes in the liver. Somatostatin (SST) was predominately expressed in intestine, brain and gonads (male) with different ontogenic patterns. The highest expression in intestine was detected at E10. There was ontogenic shift from intestine to brain as development progressed. Expression pattern of SSTRs in brain, intestine and kidney was similar to human embryonic expression. In liver, the ontogenic expression pattern of SST and its receptors was associated to methylation status of the respective promoters. Methylation of site Sp1 determines expression level of SST, SSTR1, SSTR2 and SSTR3 while site a is important in governing the expression of SSTR4 and SSTR5. The results show that ontogenic expression profile of chicken SST and SSTRs is time and tissue specific.
本研究旨在探讨鸡胚（Gallus gallus）中生长抑素及其五种受体亚型（SSTR1-5）mRNA 表达的个体发生和组织分布。研究了鸡胚在孵化前的第 10、16 和 21 天（E 龄）的大脑、性腺（雄性）、肠、肾、肝、肌肉、胃和卵黄囊膜（YSM）。采用亚硫酸氢盐测序 PCR（BSP）测定了肝脏中所有六个基因启动子区域的甲基化状态。生长抑素（SST）主要在肠、脑和性腺（雄性）中表达，具有不同的个体发生模式。在 E10 时，肠中的表达最高。随着发育的进行，表达模式从肠转移到脑。SSTRs 在脑、肠和肾中的表达模式与人类胚胎表达相似。在肝脏中，SST 及其受体的个体发生表达模式与各自启动子的甲基化状态有关。Sp1 位点的甲基化决定了 SST、SSTR1、SSTR2 和 SSTR3 的表达水平，而位点 a 对于调控 SSTR4 和 SSTR5 的表达很重要。结果表明，鸡 SST 和 SSTRs 的个体发生表达谱具有时间和组织特异性。
