中国荷斯坦牛IGF1R基因对产奶性状的遗传效应分析  

Genetic Effect Analysis of IGF1R Gene on Milk Production Traits in Chinese Holstein Cow(Bos taurus)

作　　者：刘亚楠 彭朋 郑伟杰 韩博[1] 杨晨东 李建明 马亚宾 蒋桂娥 倪俊卿 孙东晓[1] LIU Ya-Nan;PENG Peng;ZHENG Wei-Jie;HAN Bo;YANG Chen-Dong;LI Jian-Ming;MAYa-Bin;JIANG Gui-E;NI Jun-Qing;SUN Dong-Xiao(College of Animal Science and Technology,China Agricultural University,Beijing 100193,China;Hebei Provincial Station for Livestock Varieties Producing and Spreading,Shijiazhuang 050061,China)

机构地区：[1]中国农业大学动物科技学院,北京100193 [2]河北省畜牧良种工作总站,石家庄050061

出　　处：《农业生物技术学报》2021年第8期1518-1527,共10页Journal of Agricultural Biotechnology

基　　金：河北省重点研发计划(21326358D);国家自然科学基金(31872330;32072716);长江学者和创新团队发展计划(IRT15R62)。

摘　　要：本课题组前期通过转录组测序发现,中国荷斯坦母牛(Bos taurus)干奶期肝脏组织中类胰岛素生长因子Ⅰ型(insulin-like growth factorⅠ,IGF1)受体基因(IGF1 receptor,IGF1R)表达量显著高于泌乳初期和高峰期。IGF1R是一种受体酪氨酸激酶,在IGF的信号传导中起着至关重要的作用。为验证IGF1R基因是否对产奶性状具有显著遗传效应,本研究利用40头荷斯坦公牛的混池基因组DNA,采用PCR产物直接测序法扫描IGF1R基因的全部编码区以及上下游调控区各2000 bp区段以鉴定潜在多态位点,在947头中国荷斯坦母牛实验群体中,对鉴定到的SNP位点通过靶向测序基因型分型方法测定基因型,采用动物模型与5个产奶性状进行关联分析。结果共检测到7个SNP位点,1个位于外显子、5个位于内含子区、1个位于3'调控区;单标记关联分析结果表明:6个SNP位点与产奶量、乳脂量、乳蛋白量和乳蛋白率性状显著关联(P=0.0146~<0.0001);显性效应、等位基因替代效应达到显著(P<0.05)或极显著(P<0.01);SNP位点间连锁不平衡程度(linkage disequilibrium,LD)计算结果显示:7个多态性位点存在连锁(r 2=0.85~0.99),可划分为3个单倍型块;单倍型关联分析结果显示:单倍型块1与5个产奶性状均未达到显著关联(P>0.05),单倍型块2和3与产奶量、乳脂量和乳蛋白量性状呈现极显著关联(P=0.0003~<0.0001),单倍型1和单倍型2为优势单倍型,可分别提高产奶量、乳脂量和乳蛋白量。由此,IGF1R基因对中国荷斯坦牛产奶性状产奶量、乳脂量和乳蛋白量性状遗传效应显著,可望向奶牛基因组选择提供分子标记。Previous study in this group discovered that the expression level of insulin-like growth factorⅠ(IGF1)receptor(IGF1R)gene in liver tissue of Chinese Holstein cows(Bos taurus)during the dry period was significantly higher than that in early and peak lactation periods through transcriptome sequencing.IGF1R is a receptor tyrosine kinase that plays a critical role in the signaling of the IGF family.With directly sequencing the encoding regions and 2000 bp of upstream and downstream flanking regions of IGF1R gene using the pooled DNA from 40 sires to verify the IGF1R gene genetic effects on lactation traits in dairy cows.The identified SNPs were genotyped in 947 Chinese Holstein cows individually by target sequencing technology.Association analysis was conducted between the SNPs and 5 milk traits using the animal model.As a result,a total of 7 SNPs were detected including 1 SNP located in exon,5 SNPs located in intron region and 1 SNP located in 3'flanking region.Of them,single-marker association analysis results showed that 6 SNPs were found associated with milk yield,fat yield,protein yield and protein percentage significantly(P=0.0146~<0.0001).The dominant effects or allelic substitution effects of 7 SNP sites reached significantly difference(P<0.05;P<0.01).Through linkage disequilibrium(LD)analysis,7 SNPs were linked(r 2=0.85~0.99)and formed 3 blocks.Haplotype-based association analysis showed that block 1 was not significantly associated with all the 5 milk traits(P>0.05).While block 2 and block 3 were associated with milk yield,fat yield and protein yield traits(P=0.0003~<0.0001),in which H1 and H2 were dominant haplotypes that increased milk yield,fat yield and protein yield,respectively.In conclusion,IGF1R gene had significant impacts on milk yield,fat yield and protein yield traits in dairy cow,implying it could be used as a molecular marker in genomic selection.

关 键 词：中国荷斯坦奶牛 类胰岛素生长因子Ⅰ型受体基因(IGF1R) 产奶性状 SNP 遗传效应 

分 类 号：S813.3[农业科学—畜牧学]