水牛MFSD2A基因多态性及其与产奶性状的关联分析

【目的】研究水牛主要促进因子超家族成员2a(major facilitator superfamily domain containing 2a, MFSD2A)基因多态性，并筛选与水牛产奶性状相关联的SNP。【方法】采集383头健康水牛血液DNA,利用PCR扩增和Sequenom MassARRAY飞行时间质谱技术对SNP位点进行筛选及基因型检测，并进行遗传多样性、连锁不平衡(LD)和单倍型分析，以及对不同基因型和单倍型与水牛产奶性状进行关联分析。【结果】在水牛MFSD2A基因中检出7个SNPs位点，多态信息含量(PIC)均在0.25～0.40之间，属于中度多态，除g.8290 T>C位点外，其余位点均处于Hardy-Weinberg平衡状态(P>0.05);关联分析结果表明，这7个SNPs位点与305 d产奶量均显著关联(P<0.05),且突变杂合子基因型的305 d产奶量是3种基因型中最低的，g.568 C>G和g.701 A>G位点与乳脂率显著关联(P<0.05),乳脂率从大到小依次为突变纯合子>野生纯合子>突变杂合子，g.568...

Polymorphism of MFSD2A Gene and Its Association with Milk Production Traits in Buffalo

【Objective】 In order to study the polymorphism of major facilitator superfamily domain containing 2a (MFSD2A) gene of buffalo and screen the SNP associated with milk production traits of buffalo.【Method】 The blood DNA was collected from 383 healthy buffaloes,and the SNP were screened and genotyped by PCR amplification and Se-quenom MassARRAY SNP time-of-flight mass spectrometry.The genetic diversity,linkage disequilibrium (LD) and haplotype analysis were analyzed,and the association between different genotypes and haplotypes and milk production traits was analyzed.【Result】 Seven SNPs were detected in MFSD2A gene of buffalo,and the polymorphism information content (PIC) ranged from 0.25 to 0.40,which belonged to moderate polymorphism.Except g.8290 T＞C,all the other sites were in Hardy-Weinberg equilibrium(P＞0.05).The results of association analysis showed that the seven SNPs were significantly associated with 305 d milk yield (P＜0.05),and the 305 d milk yield of mutant heterozygote was the lowest among the three genotypes.g.568 C＞G and g.701 A＞G were significantly associated with milk fat percentage (P＜0.05).The order of milk fat percentage genotypes was mutant homozygote＞wild homozygote＞mutant heterozygote.g.568 C＞G,g.3326 G＞A,g.8290 T＞C and g.8523 C＞G were significantly associated with milk protein percentage (P＜0.05),but these seven SNPs were not significantly associated with milk urea nitrogen (P＞0.05).The results of LD and haplotype analysis showed that g.568 C＞G,g.701 A＞G and g.3203 T＞G could form a haplotype module (Block 1),while g.8523 C＞G and g.9138 G＞T could form another haplotype module (Block 2).The r² of g.568 C＞G and g.701 A＞G,g.568 C＞G and g.3326 G＞A,g.8523 C＞G and g.9138 G＞T were 0.87,0.37 and 0.48,respectively,which were in a state of strong linkage disequilibrium.The milk protein percentage of H1 (CAG) haplotype in Block 1 was significantly higher than that of H2 (CAT) and H3 (GCT) haplotype (P＜0.05),and the 305 d milk yield of D3 (GG) haplotype in Block 2 was significantly higher than that of D1 (CG) and D2 (CT) haplotype (P＜0.01).【Conclusion】 The seven SNPs of MFSD2A gene were significantly associated with 305 d milk yield,g.568 C＞G and g.701 A＞G were significantly associated with milk fat percentage,g.568 C＞G,g.701 A＞G,g.3326 G＞A,g.8290 T＞C and g.8523 C＞G were significantly associated with milk protein percentage were significantly associated,and none of these seven SNPs were significantly associated with milk urea nitrogen.Homozygous genotypes had more advantages in the selection of high 305 d milk yield and milk fat percentage.H1 (CAG) and D3 (GG) haplotypes were favorable haplotypes to increase 305 d milk yield and milk protein rate in buffalo.