【摘要】 以126头纯种南阳黄牛为研究材料,利用PCR-RFLPs技术对胰岛素样生长因子2(IGF2)第2外显子的多态性及其与生长发育的相关性进行了分析。结果表明:南阳牛在该位点的遗传多态性丰富。检测到2种等位基因A和B,频率分别为0.686 5和0.313 5,A等位基因在群体中是优势等位基因;BB型个体的6、12、18、24月龄体斜长和胸围,12、18和24月龄的坐骨端宽,初生、6月龄和24月龄体重等体征性状显著地优于AA型;6月龄体斜长、12月龄的胸围、18月龄和24月龄坐骨端宽也显著优于杂合型。初步推断IGF2基因是非常有价值的辅助选择标记,可为南阳牛肉用型方向选择提供理论依据。更多还原

【Abstract】 Insulin-like growth factor 2 has profound effects on the growth and differentiation of animal embryo.Some researches indicated that the normal level of IGF2 have positive correlation with the embryo to youth growth of many large size mammals.This study was designed to investigate the polymorphism of exon 2 of IGF2 gene and its relationship with growth and development in 126 Nanyang cattle by PCR-RFLPs with BsrⅠ.The results showed that the frequencies of alleles A and B were 0.686 5 and 0.313 5 respectively.The allele A was the dominant allele in Nanyang cattle.Individuals with homozygote of allele B had a significantly higher average body weight for born six months and twenty four months age,a most significantly higher average body length and heart girth for all experiment age,a significantly higher average hucklebone width for twelve months, eighteen months and two years age than that of allele A.They also had a significantly higher body length for six month age,heart girth for twelve month age,hucklebone width for eighteen and two year age than that of heterozygote.It was concluded that IGF2 gene is the major gene affecting the growth related traits of Nanyang cattle or it links with the major gene,and the mutation could be used as the molecular genetic marker to select the cattle for faster growth.更多还原