苏淮猪肉滴水损失相关候选基因突变位点的鉴别

Identification of candidate genes and variants related to muscle drip loss in Suhuai pig

[目的]本试验旨在鉴别影响苏淮猪肉滴水损失的关键基因及位点,为苏淮猪肉品质选育提供重要分子标记。[方法]屠宰301头苏淮猪(胴体重平均为58.67 kg),测定肌肉滴水损失,分析含有胁迫相关蛋白(SAP)结构域的肌肉增强因子2激活基因(MAMSTR)rs337473375(C>T)位点、抵抗素基因(RETN)rs327132149(G>A)位点、兰尼定受体基因(RYR1)g.1843C>T位点、磷酸化酶激酶γ1基因(PHKG1)g.8283C>A位点以及一磷酸腺苷激活蛋白激酶γ3亚基基因(PRKAG3)p.Arg200Gln位点和p.Ile199Val位点等6个已知影响滴水损失的候选基因功能位点在301头苏淮猪群体中的遗传多态性,使用SAS 9.2软件的混合线性模型分析上述基因多态性与苏淮猪肌肉滴水损失的关联性。[结果]苏淮猪群体肌肉滴水损失平均为1.83%,变异系数为67.88%。其中,母猪肌肉滴水损失极显著低于阉公猪。5个候选基因的6个功能位点在苏淮猪群体中均存在多态性。其中,MAMSTR基因rs337473375(C>T)位点C、T等位基因的基因频率分别是0.661和0.339,该位点与猪肉滴水损失极显著关联;RETN基因rs327132149(G>A)位点G、A等位基因频率分别为0.032和0.968,该位点与苏淮猪肉滴水损失无关联;RYR1基因g.1843C>T位点C、T等位基因的基因频率分别是0.967和0.033,该位点与猪肉滴水损失显著关联,CC型为有利基因型;PHKG1基因g.8283C>A位点在苏淮猪群体中未发现遗传多态性,但我们在该位点前一个碱基处发现新的突变rs697732005(A>G)位点,其G、A等位基因频率分别为0.264和0.736,此位点与苏淮猪肉滴水损失显著关联,GG型为有利基因型;PRKAG3基因p.Arg200Gln位点在苏淮猪群体中未检测到多态性,但该基因p.Ile199Val位点有多态性,G、A等位基因频率分别为0.834和0.166,且此位点与滴水损失有关联的趋势。[结论]MAMSTR基因rs337473375位点、RYR1基因g.1843C>T位点和PHKG1基因的rs697732005位点是影响苏淮猪肉滴水损失的候选基因位点,可作为降低苏淮猪肉滴水损失的潜在分子标记。

[Objectives]The present study aimed to identify the key genes and variants that affect the drip loss of Suhuai pork,and provide important molecular markers for the meat quality breeding of Suhuai pig.[Methods]Total 301 Suhuai pigs(carcass weight 58.67 kg)were slaughtered,and the muscle drip loss was measured.The correlation between the genetic polymorphism of myocyte enhancer factor-2 activating motif and stress associated proteins(SAP)domain containing transcriptional regulator(MAMSTR)rs337473375(C>T),resistin(RETN)rs327132149(G>A),ryanodine receptor1(RYR1)g.1843C>T,phosphorylase kinase gamma1(PHKG1)g.8283C>A and protein kinase AMP-activated non-catalytic subunit gamma3[(PRKAG3,also known as rendement napole(RN))]p.Arg200Gln,p.Ile199Val and the phenotypic were calculated using the mixed linear model of SAS 9.2 software.[Results]The mean drip loss of muscle in Suihuai pigs was 1.83%,and the coefficient of variation was 67.88%.Within this population,the drip loss of muscle in gilts was significantly lower than that in castrated boars.Six functional loci among 5 candidate genes were polymorphic in the Suhuai pig population.The frequencies of C and T alleles at MAMSTR(rs337473375)were 0.661 and 0.339,respectively.The mutation of C>T at this locus was significantly associated with drip loss of muscle in Suihuai pigs.The frequencies of G and A alleles of RETN(rs3271322149)were 0.032 and 0.968,respectively,and this variant was not associated with the drip loss of pork.The frequencies of C and T alleles at RYR1(g.1843C>T)were 0.967 and 0.033,respectively.The C>T mutation at this locus was significantly associated with the drip loss of pork and CC was the advantageous genotype.No genetic polymorphism was found at the PHKG1(g.8283C>A)in the Suhuai pig population,but we found a new mutation rs697732005(A>G)at the base before the site.The frequencies of G and A alleles of PHKG1(rs697732005)were 0.264 and 0.736,respectively.The A>G mutation of PHKG1(rs697732005)was significantly associated with the drip loss of Suhuai pig and GG was the advantageous genotype.No genetic polymorphism was found at the PRKAG3(p.Arg200Gln)in the Suhuai pig population,but the PRKAG3(p.Ile199Val)was polymorphic,and the frequencies of G and A alleles at PRKAG3(p.Ile199Val)were 0.834 and 0.166,respectively.The A>G mutation at this locus was significantly associated with the drip loss of muscle in Suihuai pigs.[Conclusions]In conclusion,MAMSTR(rs337473375),RYR1(g.1843C>T)and PHKG1(rs697732005)were the candidate mutations that affect the drip loss of Suhuai pork,which could be used as potential molecular markers to reduce the drip loss of Suhuai pig.