贵州地方白羽鸡种MSTN基因SNP位点快速筛查及其蛋白功能预测  

Rapid screening and protein function prediction of MSTN gene SNP sites in Guizhou local chicken breeds

作　　者：龙广丽 牟腾慧 刘洋 饶永超[1,2,3] 杨德凤 谭光辉 林家栋 傅筑荫 张福平[1,2,3] LONG Guang-li;MOU Teng-hui;LIU Yang;RAO Yong-chao;YANG De-feng;TAN Guang-hui;LIN Jia-dong;FU Zhu-yin;ZHANG Fu-ping(College of Animal Science,Guizhou University/Key Laboratory of Animal Genetics,Breeding and Reproduction in the Plateau Mountainous Region,Ministry of Education/Key Laboratory of Animal Genetics,Breeding and Reproduction in Guizhou,Guiyang 550025,China;Institute of Poultry,Guizhou University,Guiyang 550025,China;Scientific Research Chicken Farm of Guizhou University,Guiyang 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,贵阳550025 [2]贵州大学家禽研究所,贵阳550025 [3]贵州大学科研鸡场,贵阳550025

出　　处：《南方农业学报》2020年第8期1840-1848,共9页Journal of Southern Agriculture

基　　金：贵州省科技计划项目(黔科合支撑〔2016〕2507号)。

摘　　要：【目的】明确贵州地方白羽鸡种肌肉生长抑制素(MSTN)基因的多态性,筛选出改良白羽鸡肉质品质的分子遗传标记,为选择培育优良肉质鸡种提供参考依据。【方法】以兴义矮脚鸡白羽品系、罗曼蛋鸡及兴义矮脚鸡白羽品系与罗曼蛋鸡杂交的自交后代(F2)为研究对象,提取3个鸡种的血液基因组DNA构建DNA混合池,PCR扩增MSTN基因全部外显子序列,直接测序筛选SNP位点并进行生物信息学分析,探究SNP位点突变对MSTN基因mRNA二级结构及编码蛋白结构和功能的影响。【结果】在鸡MSTN基因第1外显子(Exon-1)筛查到6个SNPs位点,分别为G51A、A60G、G195C、A234G、C297T和C324T,且6个SNPs位点均为同义突变。在A234G位点处检测到兴义矮脚鸡白羽系和F2代存在多态性,但罗曼蛋鸡未发生变异;在C297T位点处检测到罗曼蛋鸡存在多态性,以C为优势等位基因,而兴义矮脚鸡白羽品系和F2代均未发生变异;G51A、G60A、G159C和C324T等4个SNPs位点在3个鸡种中均存在多态性。A234G位点突变对鸡MSTN基因m RNA二级结构稳定性无影响,G51A位点突变致使MSTN基因mRNA二级结构最小自由能降低但未改变其构象,A60G、G195C、C297T和C324T等4个SNPs位点突变均引起MSTN基因mRNA二级结构和最小自由能的改变。鸡MSTN基因编码蛋白为不稳定的脂溶性蛋白,存在信号肽,但不存在跨膜区域,其二级结构由无规则卷曲、β-折叠和α-螺旋组成,且以无规则卷曲占比最高。【结论】MSTN基因在贵州地方白羽鸡种中的多态性较丰富,其中A60G、G195C、C297T和C324T等4个SNPs位点突变会导致基因mRNA二级结构的构象发生改变,可作为改良白羽鸡肉质品质的分子遗传标记进一步研究。【Objective】To identify the polymorphism of the myostatin(MSTN)gene of Guizhou local white feather chicken breeds,screen out ideal molecular genetic markers which could improve the meat quality of white feather chickens,and provide a reference for selecting and breeding excellent broiler chicken breeds.【Method】Taking Xingyi bantam white feather line,Roman laying chicken and self-progeny(F2)of cross between Xingyi bantam white feather line and Roman laying chicken as the research object,the blood genomic DNA of three chicken breeds was extracted to construct a DNA mixing pool.The PCR amplification of all exon sequences of MSTN gene was directly sequenced and screened.Then the SNP sites were bioinformatically analyzed to explore the impact of SNP site mutations on the secondary structure of MSTN gene mRNA and the structure and function of the encoded protein.【Result】Six SNPs sites were screened in the first exon(Exon-1)of the chicken MSTN gene,which were G51A,A60G,G195C,A234G,C297T and C324T,and the six SNPs sites were all synonymous mutations.At the A234G locus,polymorphisms were detected in the Xingyi bantam white feather line and F2 generation,but no mutations occurred in the Roman laying chickens;polymorphisms were detected in the Roman laying chickens at the C297T locus,with C as the dominant position.There were no mutations in Xingyi bantam white feather line and F2 generation.At four SNPs,including G51A,G60A,G159C and C324T,polymorphisms were all detected in three chicken breeds.A234G site mutation had no effect on the stability of the secondary structure of chicken MSTN gene mRNA.G51A site mutation reduced the minimum free energy of mRNA secondary structure but did not change its conformation.Four SNPs site mutations including A60G,G195C,C297T and C324T caused changes in the secondary structure and minimum free energy of MSTN gene mRNA.The chicken MSTN gene encoding protein was an unstable fat-soluble protein with a signal peptide but no transmembrane regions.Its secondary structure consisted of

关 键 词：贵州地方白羽鸡种 MSTN基因 肉质性状 SNP位点 多态性 生物信息学 

分 类 号：S831.89[农业科学—畜牧学]