水貂TYRP1基因的多态性与毛色性状的相关性分析

Relationship analysis between the polymorphism of TYRP1 gene and hair color in mink

为了研究水貂TYRP1基因多态性与毛色性状的相关性,试验首先提取384只水貂的血液基因组DNA,然后对水貂TYRP1基因外显子2,3,4进行PCR扩增并测序,通过序列比对识别单核苷酸多态性(single nucleotide polymorphism,SNP)位点并进行基因分型,统计SNP位点在不同品种水貂群体(红眼白水貂、银蓝水貂、短毛黑水貂和咖啡水貂)中的基因型频率和等位基因频率后进行遗传多样性分析,最后采用卡方(χ^(2))检验对SNP位点基因型与毛色性状进行相关性分析。结果表明:TYRP1基因外显子3,4未识别到SNP位点,而外显子2识别到1个SNP位点(C777G位点),C777G位点在4个品种水貂群体中共存在3种基因型(CC型、CG型和GG型)。红眼白水貂群体的优势基因型为GG型,优势等位基因为G;银蓝水貂、短毛黑水貂和咖啡水貂群体的优势基因型均为CC型,优势等位基因均为C,其中短毛黑水貂群体的基因型全部为CC型,等位基因全部为C。C777G位点在红眼白貂和银蓝水貂群体中极显著偏离哈代-温格平衡状态(P<0.01),在咖啡水貂群体中处于哈代-温格平衡状态(P>0.05)。红眼白、银蓝和咖啡三个品种水貂TYRP1基因C777G位点为轻度多态(PIC<0.25),短毛黑水貂TYRP1基因C777G位点无多态性(PIC=0)。4个品种水貂TYRP1基因C777G位点的纯合度(Ho)在0.6957(咖啡黑水貂)~1.0000(短毛水貂)之间,杂合度(He)在0(短毛黑水貂)~0.3043(咖啡水貂)之间,有效等位基因(Ne)在1.0000(短毛黑水貂)~1.3478(咖啡水貂)之间。C777G位点基因型与红眼白、银蓝和咖啡三个品种水貂毛色性状极显著相关(P<0.01)。说明TYRP1基因C777G位点可作为水貂毛色性状辅助选择的分子标记。

In order to study the correlation between TYRP1 gene polymorphism and hair color traits of minks,blood genomic DNA was extracted from 384 minks,followed by PCR amplification and sequencing of the TYRP1 gene exons 2,3 and 4.Identification and genotyping of single nucleotide polymorphism(SNP)sites by alignment.The genotype and allele frequencies of SNP sites in different breeds of mink populations(red-eyed white mink,silver-blue mink,short-haired black mink,and coffee mink)were counted,and the genetic diversity was analyzed.Finally,the correlation between SNP and hair color traits was analyzed by chi-square(χ^(2))test.The results showed that no SNP site was identified in exon 3 and 4,while one SNP site(C777G site)was identified in exon 2 of TYRP1 gene.There were three genotypes(CC,CG and CG)of C777G in the four breeds of mink populations.The dominant genotype in red-eyed white mink population was GG and the dominant allele was G.The dominant genotypes of silver blue mink,short-haired black mink and coffee mink populations were CC and the dominant allele was C,among which all the short-haired black mink populations were CC and the dominant allele was C.The C777G site deviated significantly from Hardy-Winger equilibrium in red-eyed white mink and silver blue mink populations(P<0.01)and was in Hardy-Winger equilibrium in coffee mink populations(P>0.05).The C777Gs site of TYRP1 gene in red-eyed white,silver blue and coffee mink was mildly polymorphic(PIC<0.25),while the C777G site of TYRP1 gene in short-haired black mink was not polymorphic(PIC=0),The homozygosity(Ho)ranged from 0.6957(coffee mink)to 1.0000(short-haired black mink),heterozygosity(He)ranged from 0(shorthaired black mink)to 0.3043(coffee mink),and effective alleles(Ne)ranged from 1.0000(short-haired black mink)to 1.3478(coffee mink).The genotypes of C777G site were significantly associated with coat color traits of red-eyed white,silver-blue and coffee minks(P<0.O1).These results indicated that C777G site of TYRP1 gene could be used as a molecular marker for assisting selection of mink hair color traits.