Wnt/β-catenin信号通路相关基因及MyHCs在猪骨骼肌发育中的表达规律  

The Expression Pattern of Wnt/β-catenin Signal Pathway Related Genes and MyHCs during Porcine Skeletal Muscle Development

作　　者：杨秋梅[1] 史新娥[1] 沈清武[1] 刘月光[1] 高晓娟[1] 陈宗正[1] 杨公社[1] 

机构地区：[1]西北农林科技大学动物科技学院动物脂肪沉积与肌肉发育实验室,杨凌712100

出　　处：《畜牧兽医学报》2011年第12期1686-1695,共10页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：转基因生物新品种培育重大专项基金(2009zx08009-157B)

摘　　要：为研究Wnt/β-catenin信号通路对猪骨骼肌纤维类型发育的影响,并探讨其潜在的作用机制。本研究以1日龄、1周龄、2周龄、1月龄、2月龄和6月龄大白猪背最长肌组织为研究材料,利用Real-time PCR、Westernblot、冰冻切片免疫组化等方法,研究Wnt/β-catenin信号通路相关基因及MyHCs在猪骨骼肌发育过程中的表达规律。Real-time PCR结果显示:MyHC-Ⅰ、GSK-3β、β-catenin和Fz3mRNA随着个体日龄增加表达量下降,My-HC-Ⅱb mRNA表达逐渐升高,MyHC-Ⅱa mRNA表达量在1日龄～2周龄阶段升高后又降低,MyHC-Ⅱx mRNA表达量变化不显著;免疫组化结果显示:快肌蛋白呈棕色,慢肌蛋白呈灰白色,在出生1日龄～1周龄时,快、慢肌呈弥散交叉分布,到2周龄时慢肌簇被快肌包被在肌束中间,随着年龄增加,慢肌簇逐渐减少。Western blot检测结果显示:慢肌蛋白从出生到2周龄显著下降,在2周龄～2月龄阶段下降不明显,生长到6月龄时又显著降低;快肌蛋白随日龄增加而增加,在2周龄～6月龄期间增加极显著;β-catenin、GSK-3β蛋白表达量与其mRNA表达一致,而p-β-catenin在2周龄时显著高于1日龄,且随后持续上调;Tyr216 p-GSK-3β蛋白表达量早期生长下调极显著;Ser9p-GSK-3β蛋白表达量则是在后期生长显著降低。上述基因表达变化规律揭示,Wnt/β-catenin信号通路相关基因β-catenin、Fz3、GSK-3β与MyHC-Ⅰ表达呈正相关,与MyHC-Ⅱ表达呈负相关,其在骨骼肌生长过程中对肌纤维类型组成具有重要影响。The aim of this study was to investigate the mechanism of effect of Wnt/β-catenin signal pathway on the porcine skeletal muscle fiber types development.The longissimus doris from Large White pigs at the age of 1 day,1 week,2 weeks,1 month,2 months and 6 months were used as research materials.Real-time PCR,Western blot and immunohistochemical methods were used to identify the morphologic and histologic change of porcine skeletal muscle during development process,and research the expression of Wnt/β-catenin signal pathway related genes and MyHCs during longissimus doris development.Real-time PCR results showed that MyHC-Ⅰ,GSK-3β,β-catenin and Fz3 mRNA expression decreased,MyHC-Ⅱb mRNA increased gradually,MyHC-Ⅱa mRNA increased and then decreased from 1 day to 2 weeks old,and MyHC-Ⅱx mRNA did not change significantly during the development process of porcine longissimus doris.The results of immunohistochemical showed that the slow mucle protein was gray;fast muscle protein was brown.The fast and slow muscle fibers were cross-dispersion distribution from 1 day to 1 week old,then slow fibers were coated by fast muscle fibers after 2 weeks old and then the slow muscle fibers decreased gradually.Western bolt results showed that the slow muscle protein decreased significantly from 1 day to 2 weeks old,its change was not significant from 2 weeks to 2 months old,then decreased at 6 months old.The fast muscle protein increased with development,it was extremely increased from 2 weeks to 6 months old.The protein expression of β-catenin and GSK-3β were consistent with their mRNA.The protein of p-β-catenin was much higher at 2 weeks old than that at 1 day old,and then increased continuously,Tyr216p-GSK-3β was reduced significantly during early growth,ser9p-GSK-3β was decreased during later growth.These results suggest that the expression of Wnt/β-catenin signaling pathway related genes β-catenin,Fz3 and GSK-3β were positively correlated with MyHC-Ⅰ,but negatively correlated with MyHC-Ⅱ.It played an impor

关 键 词：WNT/Β-CATENIN信号通路 肌纤维类型 猪 背最长肌 发育 

分 类 号：S828[农业科学—畜牧学] S813.3[农业科学—畜牧兽医]