circRIPK2在鸡骨骼肌细胞增殖分化中的调控作用

目的 探索circRIPK2在鸡骨骼肌生长发育中的功能及作用机制。方法 依据反向剪切位点设计收敛、发散引物,并结合Sanger测序验证circRIPK2的环形结构。利用RT-PCR探究不同发育时期circRIPK2的表达水平。通过构建过表达载体,结合EdU、流式细胞术和RT-PCR,探究circRIPK2对鸡原代成肌细胞增殖分化的影响。结果 PCR电泳结果及Sanger测序证明circRIPK2环化位点真实存在。RT-PCR结果表明,和对照组相比,过表达circRIPK2后,对细胞增殖有抑制作用的标记基因p21的mRNA表达上调20%,对细胞增殖有促进作用的标记基因Cyclin B2、Cyclin D1、Cyclin D2和PCNA的mRNA表达分别下调39%、22%、29%和45%;肌分化标记基因MyHC、MYOG和Myomaker的mRNA表达分别上调了39%、56%和25%。EdU检测细胞增殖和流式细胞术检测细胞周期变化的结果表明,circRIPK2抑制细胞增殖进程。结论 circRIPK2可能通过抑制成肌细胞增殖、促进成肌细胞分化,从而影响鸡骨骼肌的生长发育过程。     

MicroRNA-22 inhibits proliferation and promotes differentiation of satellite cells in porcine skeletal muscle

Pig is an important economic animal in China. Improving meat quality and meat productivity is a long time issue in animal genetic breeding. Micro RNAs(mi RNAs) are short non-coding RNAs that participate in various biological processes, such as muscle development and embryogenesis. mi R-22 differentially expresses in embryonic and adult skeletal muscle. However, the underlying mechanism is unclear. In this study, we investigated mi R-22 function in proliferation and differentiation of porcine satellite cells(PSCs) in skeletal muscle. Our data show that mi R-22 expressed in both proliferation and differentiated PSCs and is significantly upregulated(P0.05) during differentiation. After treated with the mi R-22 inhibitor, PSCs proliferation was significantly increased(P0.05), as indicated by the up-regulation(P0.01) of cyclin D1(CCND1), cyclin B1(CCNB1) and down-regulation(P0.05) of P21. Conversely, over-expression of mi R-22 resulted in opposite results. Differentiation of PSCs was significantly suppressed(P0.05), evidenced by two major myogenic markers: myogenin(Myo G) and myosin heavy chain(My HC), after transfecting the PSCs with mi R-22 inhibitor. Opposite results were demonstrated in the other way around by transfection with mi R-22 mimics. In conclusion, the data from this study indicated that mi R-22 inhibited the PSCs proliferation but promoted their differentiation.     

HMGCS1基因对猪肌肉生长发育的影响及 miRNA-18a/b对HMGCS1基因的调控

【目的】研究HMGCS1基因对猪骨骼肌生长发育的影响及其靶标的验证。【方法】采用real-time PCR对通城猪不同组织以及背最长肌不同发育时间点的HMGCS1基因的表达变化进行检测。【结果】①HMGCS1基因在成年猪肺组织中的表达量最高;②在背最长肌发育中,该基因分别在胚胎期33 和65 d高表达,出生后20、30、40和60 d低表达;③双荧光素酶试验显示,转染miR-18a/b minics组荧光素酶活性低于对照组。【结论】HMGCS1参与了猪骨骼肌生长发育过程,并受miR-18a/b的调控,是猪的产肉性状的潜在候选基因。     

骨骼肌兴奋收缩偶联潜伏期肌浆网内Ca~(2 )变化的研究——细胞化学法及X-射线能量色散谱微区分析

报道了采用红外探测－计算机控制的超低温快速冷冻固定技术、Ｘ－射线能量色散谱微区定量分析及Ｃａ２＋细胞化学技术对骨骼肌收缩潜伏期时肌浆网内的Ｃａ２＋进行了分析,从超微结构形态学的角度对骨骼肌兴奋－收缩偶联发生时,肌浆网内Ｃａ２＋的作用进行了研究,这对揭示骨骼肌兴奋－收缩偶联时,肌浆网内Ｃａ２＋的释放机理研究有重要意义。