牛PON1基因对生长和胴体性状的影响

PON1 Gene SNPs and Association with Growth and Carcass Traits in Beef Cattle

克隆了牛PON1基因,检测其外显子上的SNPs,对EcoRⅤ和AluI 2种限制性内切酶酶切PON1基因后的等位基因频率和所产生的基因型频率进行估计,并对EcoRⅤ和AluI 2种酶酶切后所产生的多态性对生长和胴体性状的影响进行分析。实验动物为30头安格斯、30头海福特和28头西门塔尔牛。关联分析应用SAS9.1的GLM过程中最小二乘均数Tukey′s检验进行分析。结果表明,PON1基因克隆获得1 205 bp的cDNA序列,其编码区为1 068 bp,编码355个氨基酸;外显子SNPs检测表明,仅在其第6外显子区域存在2个突变位点,且没有引起氨基酸变异,但可分别被EcoRⅤ和AluI 2种酶酶切。EcoRⅤ位点,AG基因型的个体有着较高的试验前体质量(329.97±6.08)kg,宰前质量(577.56±8.32)kg,净肉质量(275.89±4.05)kg和较为适宜的嫩度(3.10±0.19)kg(P<0.05);AluI位点,AA基因型的个体也有着较高的试验前体质量(333.37±8.93)kg,宰前质量(576.82±13.18)kg,净肉质量(275.49±6.43)kg和平均日增质量(0.68±0.02)kg.d-1(P<0.05);并在此位点不同的基因型个体间肉色评分有着显著的差异(P<0.05)。在品种和基因型之间除了全骨质量、眼肉质量、大理石花纹评分、眼肌面积和肉色评分外,其它性状均存在显著的差异(P<0.05)。连锁分析表明,作为一个新陈代谢功能基因,PON1基因的单核苷酸多态性可能直接影响肉牛的背膘厚,如AeAeGaGa基因型。

In order to estimate the allelic and genotypic frequencies at the PON1/EcoR Ⅴ and PON1/AluⅠ loci and association analysis between these SNPs and growth and carcass traits. The cDNA of bovine PON1 gene was cloned, and the SNPs in its exons were detected. Genotyping was performed on 30 Angus, 30 Hereford and 28 Simmental cattles using the GLM procedure of SAS and the least square means of the genotypes were compared by the Tukey＇s test. 1 205 bp eDNA sequence were obtained, including 1 068 bp ORF region and which encodes 355 amino acids residues, and was accessed by GenBank, the accession number is EU289337. Two SNPs were detected in exon6 only. Individuals with AG genotype at the PON1/EcoR Ⅴ locus have higher weight at the time of entry into the fattening corrals （329.97±6.08）kg and close to the time of slaughter （577.56±8.32）kg and net meat weight （275.89±4.05）kg, fitted tenderness （3.10±0.19）kg （P〈0.05） ; Individuals with AA genotype at PON1/Alu Ⅰ locus has higher weight at the time of entry （333.37±8.93）kg and slaughter （576.82± 13.18）kg and net meat weight （275.49±6.43）kg, and average daily gain （0.68±0.02）kg· d^-1 （P〈0.05）. The meat color score is also significant higher （P〈0.05）. Between genotypes and breeds, there were significant difference observed except TBW, REMG, MBS, REA and MCS （P〈0.05）. As a metabolism gene, genotypes of the SNPs of PON1 gene might be reflecting BFT directly, such as AeAeGaGa genotype.