内蒙古白绒山羊褪黑激素受体基因SNP与产绒性状的关联

摘要

[Objective] Correlations between SNP of cashmere goat melatonin receptor (MTNR) gene and cashmere-producing traits were studied to find molecular marker of MAS for molecular breeding. [Method] Arbas white cashmere goats and partial sequences of MTNRla and lb genes were used as experimental samples and candidate genes, respectively. PCR-SSCP and DNA sequencing technologies were conducted to detect their single nucleotide polymorphism. Results were analyzed by least square meanrn(LSM) among production traits of genotypes. [Result] There was no SSCP in the exons 1 and 2 of MTNRla gene and the exon 1 of MTNRlb gene, while there was the SSCP in the exon 2 of MTNRlb gene and three of SNP were detected. P4 primer loci existed in C-G mutation of NM_001206907:g.648 bp which didn't result in change of amino acid, and G-A mutation of NM_001206907:g.665 bp which led to CGC-CAC of the 223rd codon from Arg into His. The results showed that polymorphism loci had an significant effect on cashmere yield (P<0.05), and cashmere yield of AA genotype increased by 98.78 g and 148.23 g, as compared to AB and BB, respectively. Meanwhile, there was a significant correlation (P<0.05) in interaction effect between the polymorphism loci genotype and age cashmere thickness. P5 primer loci existed in G-A mutation of NM001206 907:g.l015 bp which led to GGC-AGC of the 339th codon from Gly into Ser. The analyses indicated that interaction effect of the polymorphism loci genotype and age was the marginal significant correlation (P<0.1) with cashmere Fineness. P4 and P5 primes locus were not significantly (P >0.05) with kidding number and birth weight. [Conclusion] P4-AA genotype can be used as molecular marker of MAS for cashmere-producing traits of Inner Mongolian Arbas white cashmere goats.%[目的]研究绒山羊褪黑激素受体(melatonin receptor,MTNR)基因的SNP与绒山羊产绒性状的关系,寻找可用于辅助选择的分子标记.[方法]以内蒙古阿尔巴斯型自绒山羊为研究对象,选择绒山羊褪黑激素受体(MTNR1a和MTNR1b)基因部分序列作为候选基因,采用PCR-SSCP分子标记技术和DNA测序技术研究其多态性,然后运用最小二乘方差分析方法,对各基因型间生产性状指标进行差异显著性检验.[结果]①在绒山羊MTNR1a基因外显子1和2,以及MTNR1b基因外显子1没有检测到SSCP多态,而在绒山羊MTR1b基因外显子2中存在SSCP多态,首次检测到了3个SNP;②P4引物位点存在NM_001206907:g.648 bp处C-G突变,该突变没有导致氨基酸的改变；以及NM_001206907:g.665 bp处的G-A突变,该突变导致第223个密码子CGC变成CAC,从而使精氨酸变成组氨酸(Arg-His);方差分析表明,该位点多态对绒山羊产绒量有显著影响(P＜0.05)；③AA基因型具有较高的产绒量,比AB、BB基因型产绒量分别高98.78和148.23 g,同时该多态位点基因型与年龄互作效应对绒山羊绒厚度有显著影响(P＜0.05)；④P5引物位点存在NM_001206907:g.1 015 bp处的G-A突变,该突变导致第3 39个密码子GGC变成AGC,从而使甘氨酸变成丝氨酸(Gly-Ser),分析表明该多态位点基因型与年龄互作效应对绒山羊绒细度存在边际显著影响(P＜0.1)；⑤这两个位点多态对绒山羊产羔数量、羔羊初生体重等繁殖性状均无显著影响(P＞0.05).[结论]P4-AA基因型可以作为内蒙古阿尔巴斯型白绒山羊产绒量性状辅助选择的标记基因型.