Liu Yanli, Guo Wei, Pu Zhenyu, Li Xueyuan, Lei Xinyu, Yao Junhu, Yang Xiaojun
College of Animal Science and Technology, Northwest A&F University, Yangling, China, 712100.
College of Animal Science and Technology, Northwest A&F University, Yangling, China, 712100
Poult Sci. 2016 Jun 1;95(6):1396-402. doi: 10.3382/ps/pew043. Epub 2016 Mar 4.
The insulin-like growth factors ( IGFS: ) are synthesized in tissues and play an important role in embryonic development of avian via autocrine/paracrine mechanisms. In the study, mRNA expression of IGFs were detected by real-time PCR in the muscle and liver from d 10 to 20 of chick embryo ( E10: to E20: ). Methylation of IGF1 promoter in the muscle was analyzed by bisulfite sequencing PCR as well as IGF2 promoter in the liver. These results showed that there was obviously IGF1 expression in liver at E19 and E20. The higher IGF1 expression in muscle was found during E15 to E18 with the peak on E17, and then declined. Correspondingly, the lowest methylation level of IGF1 promoter was detectable on the same embryonic d 17. Expression of IGF2 in muscle increased gradually during embryonic growth and showed higher level in the later stages (E17 to E20) when IGF1 expression began to decrease. IGF2 expression in liver reached the first peak on E14, then declined but gradually elevated from E17. IGF2 promoter methylation in liver showed gradual decline on d 12, 15, 17 and 19 of incubation, meanwhile IGF2 expression of liver increased gradually. These results suggested that IGF1 and IGF2 might separately be more important for muscle and liver growth in chick embryonic development. Variation of IGFs expression during the incubation might be concerned with the methylation of gene promoter. The profile of IGFs expression in chick embryonic tissues may be meaningful for understanding organ growth and embryonic development in chick.
胰岛素样生长因子（IGFs）在组织中合成，并通过自分泌/旁分泌机制在禽类胚胎发育中发挥重要作用。在本研究中，采用实时荧光定量PCR检测了鸡胚第10天至20天（E10至E20）肌肉和肝脏中IGFs的mRNA表达。通过亚硫酸氢盐测序PCR分析了肌肉中IGF1启动子以及肝脏中IGF2启动子的甲基化情况。结果表明，在E19和E20时肝脏中IGF1表达明显。在E15至E18期间肌肉中IGF1表达较高，在E17达到峰值，随后下降。相应地，在胚胎第17天可检测到IGF1启动子的最低甲基化水平。肌肉中IGF2的表达在胚胎发育过程中逐渐增加，并在IGF1表达开始下降的后期阶段（E17至E20）呈现较高水平。肝脏中IGF2的表达在E14达到第一个峰值，然后下降，但从E17开始逐渐升高。肝脏中IGF2启动子甲基化在孵化的第12、15、17和19天呈逐渐下降趋势，与此同时肝脏中IGF2的表达逐渐增加。这些结果表明，在鸡胚发育过程中，IGF1和IGF2可能分别对肌肉和肝脏生长更为重要。孵化过程中IGFs表达的变化可能与基因启动子的甲基化有关。鸡胚组织中IGFs的表达谱对于理解鸡的器官生长和胚胎发育可能具有重要意义。
