关岭牛MEF2A和MEF2B基因克隆及其组织表达特征分析  

Cloning and tissue expression analysis of MEF2A and MEF2B genes in Guanling cattle

作　　者：孙金魁 许厚强 阮涌 宋林锦 许家利 陈晨 石鹏飞 SUN Jin-kui;XU Hou-qiang;RUAN Yong;SONG Lin-jin;XU Jia-li;CHEN Chen;SHI Peng-fei(College of Animal Science,Guizhou University/Key Laboratory of Plateau Mountain Animal Genetics,Breeding and Reproduction,Ministry of Education/Guizhou Key Laboratory of Animal Genetics,Breeding and Reproduction,Guiyang,Guizhou 550025,China)

机构地区：[1]贵州大学动物科学学院/高原山地动物遗传育种与繁殖教育部重点实验室/贵州省动物遗传育种与繁殖重点实验室,贵州贵阳550025

出　　处：《南方农业学报》2022年第9期2643-2653,共11页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(31571279);教育部促进与美大地区科研合作与高层次人才培养项目([2015]2062号)。

摘　　要：【目的】探究肌细胞增强因子-2(MEF2A和MEF2B)的生物学信息特征及其在关岭牛不同发育阶段各器官组织中的表达情况,为揭示MEF2A和MEF2B基因在关岭牛生长发育过程中的作用机制及挖掘地方种质资源提供理论参考。【方法】通过RT-PCR克隆MEF2A(NM_001083638.2)和MEF2B(NM_001145793.1)基因编码区(CDS)序列,利用ProtScal、NetPhs 3.1、SOPMA、ProtParam、PSORT II Preadict、SWISS-MODEL等在线软件进行生物信息学分析,同时采用实时荧光定量PCR检测MEF2A和MEF2B基因在关岭牛不同发育阶段(犊牛、青年牛和成年牛)各器官组织中的表达水平。【结果】关岭牛MEF2A和MEF2B基因CDS序列分别编码492和368个氨基酸残基;MEF2A和MEF2B蛋白相对分子量分别为52和39 k D,对应的理论等电点(p I)为9.07和9.35,均属于碱性不稳定蛋白。关岭牛MEF2A和MEF2B蛋白以无规则卷曲和α-螺旋为主,主要定位于细胞核(分别占60.9%和52.2%)。关岭牛MEF2A基因与与挪威鼠和绵羊的MEF2A基因遗传距离较近,关岭牛MEF2B基因则与牦牛和绵羊的MEF2B基因遗传距离较近。实时荧光定量PCR检测结果显示,MEF2A和MEF2B基因在关岭牛不同发育阶段的心脏、肝脏、脾脏、肺脏、肾脏、里脊和脂肪等7个组织中均有表达,且受生长发育阶段的影响。其中,MEF2A基因在犊牛各器官组织中的相对表达量极显著高于在青年牛和成年牛(P<0.01,下同),随着年龄的增长,MEF2A基因在关岭牛心脏中的相对表达量极显著高于其他组织;MEF2B基因在青年牛和成年牛的相对表达量极显著高于犊牛,且在关岭牛心脏、肝脏和脾脏中的表达量与年龄呈正相关。【结论】MEF2A基因在关岭牛不同发育阶段心脏中高表达,而MEF2B基因在关岭牛不同发育阶段肺脏和脾脏中高表达,但在里脊中的表达相对较低。可见,MEF2A和MEF2B基因在关岭牛的生长发育过程中发挥重要作用。【Objective】To explore the biological characteristics of myocyte enhancer factor-2(MEF2A and MEF2B)and its expression in organs and tissues at different developmental stages of Guanling cattle,in order to provide theoretical reference for revealing the action mechanism of MEF2A and MEF2B genes in the growth and development of Guanling cattle and exploring local germplasm resources.【Method】The coding regions(CDS)of MEF2A(NM_001083638.2)and MEF2B(NM_001145793.1)were cloned by RT-PCR. Bioinformatics analysis was conducted by using ProtScal,NetPhs3.1,SOPMA,ProtParam,PSORT II Preadict,SWISS-MODEL and other online software. At the same time,real-time fluorescence quantitative PCR was used to detect the expression levels of MEF2A and MEF2B genes in organs and tissues of different developmental stages of Guanling cattle(calves,young and adult cattle).【Result】The CDS sequences of MEF2A and MEF2B genes in Guanling cattle encoded 492 and 368 amino acid residues,respectively. The relative molecular weights of MEF2A and MEF2B proteins were 52 and 39 k D,respectively,and the corresponding theoretical isoelectric points(pI)were 9.07 and 9.35. They were basic-unstable protein. The MEF2A and MEF2B proteins of Guanling cattle were dominated by random curling and α-helix,and were localized in the nucleus(60.9% and 52.2% respectively). The MEF2A gene of Guanling cattle was closely related to the MEF2A gene of Norwegian mice and sheep,and the MEF2B gene of Guanling cattle was closely related to the MEF2B gene of yak and sheep. Real-time fluorescence quantitative PCR results showed that MEF2A and MEF2B genes were expressed in seven tissues including heart,liver,spleen,lung,kidney,tenderloin and fat of Guanling cattle at different developmental stages,and were affected by the growth stage. The relative expression level of MEF2A gene in organ tissues of calves was significantly higher than that in young and adult calves(P<0.01,the same below),and the relative expression level of MEF2A gene in heart of Guanling cattle was sig

关 键 词：关岭牛 MEF2A基因 MEF2B基因 表达特征 生长发育 

分 类 号：S823.81[农业科学—畜牧学]