绵羊SPP1和PLCB3基因多态性与产羔数的关联分析

试验旨在探究SPP1基因g.36651870T>C位点多态性、PLCB3基因g.41871219T>C位点多态性与绵羊产羔数之间的关系,以期寻找绵羊产羔数性状相关的分子标记。利用全基因组重测序结合Sequenom MassARRAY誖SNP技术对多羔羊(小尾寒羊、湖羊、策勒黑羊)和单羔羊(滩羊、苏尼特羊、萨福克羊和草原型藏羊)7个绵羊品种SPP1、PLCB3基因的2个位点进行多态性检测,并与小尾寒羊产羔数进行关联分析。结果表明:2个位点均存在TT、TC和CC三种基因型。SPP1基因g.36651870T>C位点的基因型频率和等位基因频率在两类绵羊品种间差异极显著(P<0.01);PLCB3基因g.41871219T>C位点基因型频率在两类绵羊品种间差异不显著(P>0.05),等位基因频率差异显著(P<0.05)。群体遗传学分析表明,SPP1基因g.36651870T>C位点在小尾寒羊、苏尼特羊、萨福克羊和湖羊中均表现为中度多态(0.25≤PIC<0.5),在滩羊、策勒黑羊和草原型藏羊中表现为低度多态(PIC<0.25);PLCB3基因g.41871219T>C位点在滩羊中表现为中度多态(0.25≤PIC<0.5),在其余6个绵羊品种中均表现为低度多态(PIC<0.25)。卡方适合性检验表明,SPP1基因g.36651870T>C位点在7个绵羊品种中均处于哈代-温伯格平衡状态(P>0.05);PLCB3基因g.41871219T>C位点在小尾寒羊、滩羊、苏尼特羊、策勒黑羊、草原型藏羊5个品种中处于哈代-温伯格平衡状态(P>0.05)。关联分析表明,PLCB3基因g.41871219T>C位点多态性与小尾寒羊第1胎产羔数有显著关联(P<0.05),TT基因型个体产羔数显著高于CC基因型个体;SPP1基因g.36651870T>C位点多态性与小尾寒羊不同胎次产羔数之间无显著关联(P>0.05)。综上,PLCB3基因g.41871219T>C位点对小尾寒羊产羔数性状选育具有一定的参考意义,SPP1基因g.36651870T>C位点不适用于小尾寒羊产羔数性状选育。

Polymorphisms of SPP1 and PLCB3 Genes and Their Association with Litter Size in Sheep

This study aimed to explore the association of polymorphisms of SPP1 gene(g.36651870 T>C)and PLCB3 gene(g.41871219 T>C)and litter size in sheep,searching for new molecular markers for litter size trait in sheep.Based on whole-genome resequencing,Sequenom Mass ARRAY誖SNP technology was used to detect polymorphisms at g.36651870 T>C locus of SPP1 gene and g.41871219 T>C locus of PLCB3 gene in seven sheep breeds including polytocous sheep(Small-tail Han sheep,Hu sheep and Cele Black sheep)and monotocous sheep(Tan sheep,Sunite sheep,Suffolk sheep and Tibetan sheep),then the association between the loci and litter size in Small-tail Han sheep was analyzed.The results showed that TT,TC and CC genotypes were found at both loci.The genotype frequency and allele frequency of g.36651870 T>C locus were extremely significantly different between polytocous and monotocous sheep(P<0.01),and the allele frequency of g.41871219 T>C locus was significantly different between polytocous and monotocous sheep(P<0.05).Population genetic analysis indicated that the g.36651870 T>C locus was at moderate polymorphism in Small-tail Han sheep,Sunite sheep,Suffolk sheep and Hu sheep(0.25≤PIC<0.5),it was at low polymorphism in Tan sheep,Cele Black sheep and Tibetan sheep(PIC<0.25).The g.41871219 T>C locus was at moderate polymorphism in Tan sheep(0.25≤PIC<0.5),it was at low polymorphism in other six sheep breeds(PIC<0.25).Theχ2 test indicated that the g.36651870 T>C locus was under Hardy-Weinberg equilibrium(HWE)in seven sheep breeds(P>0.05).The g.41871219 T>C locus was under HWE in Small-tail Han sheep,Tan sheep,Sunite sheep,Cele Black sheep and Tibetan sheep.The association analysis showed that there was a significant correlation between the polymorphism of g.41871219 T>C locus and the first parity litter size of Small-tail Han sheep,the litter size of TT was significantly higher than CC(P<0.05),while the g.36651870 T>C locus had no significant correlation with the litter size of the first three parities in Small-Tail Han sheep(P>0.05).In conclusion,the g.41871219 T>C locus of PLCB3 gene may provide a valuable reference to litter size trait selection in Small-tail Han sheep and the g.36651870 T>C locus of SPP1 gene may not suitable for breeding of Small-tail Han sheep.