鸡Myf6基因遗传多态性及其遗传效应研究

采用测序和单链构象多态(SSCP)的方法分析了Myf6基因在5个优质肉鸡纯系和3个杂交配套系中的遗传分布、遗传变异及群体杂合性等群体遗传信息, 并分析了Myf6基因对胴体性状及肉质性状的遗传效应。结果发现该基因的CDS区域非常保守, 仅在外显子1的47位处发生点突变由G→A, 由于人工选育的原因, 该基因不同基因型的分布在2个优质肉鸡纯系中偏离了Hardy-Weinberg平衡, 并且杂合度较低, 遗传一致性较高, 但在3个杂交配套系中仍都服从Hardy-Weinberg平衡, 杂合度较高, 达到了配套杂交的目的。野生型A基因可显著地提高活重、屠体重、胸肌重和腿肌重(P <0.05), 同时也会降低肉的嫩度。具体地讲, A基因对增加活重、屠体重、胸肌重和腿肌重的加性效应值分别为45.54 g, 41.03 g, 6 g和9.775 g; 对增加肌纤维直径和肌纤维密度的加性效应值分别为1.025 mm和-29.99 mm2。

Genetic diversity and genetic effects of Myf6 gene in chickens

The population genetic information about genetic distribution, variation and heterozygosity of Myf6 gene in five purelines and three crossbreds of chicken was analyzed using PCR-SSCP. And the genetic effects of Myf6 gene on fiber density and partial carcass traits were investigated. Only one mutation G/A at base position 47 of the whole CDS was found among individuals in each line. The distribution of Myf6 genotype strayed off the Hardy-Weinberg equilibrium and the heterozygosity was low in two purelines but not in three crossbreds. The wild-type allele A had significant positive effects on live-weight, carcass-weight, breast-muscle-weight and leg-muscle-weight (P<0.05), but had negative effects on most of meat quality traits. The A allele had additive effects of increasing 45.54 g of the live-weight, 41.03 g of the carcass-weight, 6 g of the breast-muscle-weight, 9.775 g of the leg-muscle-weight. The A allele had dominant effects of increasing 1.025 mm of the diameter of muscle fiber, -29.99 mm2 of the density of muscle fiber.