滩寒杂交F1代BMP15和GDF9基因多态性及不同基因型对繁殖性状影响的研究

Study of BMP15 and GDF9 gene polymorphisms and the effects of different genotypes on reproductive traits in the F1 generation of Tan-Han sheep

为了研究绵羊高繁殖力候选基因骨形态发生蛋白15(bone morphogenetic protein 15, BMP15)基因和生长分化因子9(growth differentiation factor 9,GDF9)基因的多态性及不同基因型对滩寒杂交F1代群体繁殖性状的影响,试验以采集的915份滩寒杂交F1代群体血液样本为研究对象,采用飞行时间质谱基因分型技术进行SNP位点分型和遗传多态性分析,并利用Sanger测序技术进行验证,然后对不同基因型与滩寒杂交F1代群体繁殖性状和泌乳性状分别进行关联分析。结果表明:BMP15和GDF9基因SNP位点在915份DNA样本中均呈集中聚类分布。滩寒杂交F1代群体BMP15和GDF9基因均存在AA、AB、BB 3种基因型,其中BMP15基因在滩寒杂交F1代群体中的优势等位基因为A基因,基因型频率为0.69;GDF9基因在滩寒杂交F1代群体中的优势等位基因为A基因,基因型频率为0.58。BMP15和GDF9基因SNP位点在滩寒杂交F1代群体中均处于中度多态,GDF9基因处于Hardy-Weinberg平衡状态(P>0.05)。BMP15和GDF9基因AA基因型在滩寒杂交F1代群体中的产羔数均高于AB和BB基因型,其中BMP15基因AA和BB基因型第2胎次产羔数显著高于AB基因型(P<0.05),AA基因型第3胎次产羔数显著高于AB和BB基因型(P<0.05);GDF9基因型AA和AB基因型第1胎次产羔数显著高于BB基因型(P<0.05)。滩寒杂交F1代BMP15基因AA基因型有421只,GDF9基因AA基因型有315只泌乳周期为>90 d~<150 d,经计算占比均高于50%,并且与AB、BB基因型比较均差异显著(P<0.05)。说明BMP15和GDF9基因的多态位点与AA基因型有可能成为提高滩寒杂交群体繁殖性状的分子标记。

In order to study the polymorphisms of bone morphogenetic protein 15(BMP15) and growth differentiation factor 9(GDF9) which was the candidate genes for high fecundity in sheep, and the effects of different genotypes on reproductive traits in the F1 generation population of Tan-Han sheep, the experiment was conducted with 915 blood samples collected from the F1 generation population of Tan-Han sheep, and time-of-flight mass spectrometry genotyping technology was used to carry out rapid SNP typing, which was validated by Sanger sequencing technology. The association analysis was then performed between different genotypes and reproductive traits, lactation traits respectively in the F1 generation population of Tan-Han sheep. The results showed that both BMP15 and GDF9 gene SNP loci showed a concentrated clustering distribution in 915 DNA samples. Both the BMP15 and GDF9 genes of the F1 generation population of Tan-Han sheep had three genotypes, AA, AB and BB;among them, the dominant allele of BMP15 gene in the F1 generation population of Tan-Han sheep was A gene with a genotype frequency of 0.69;the dominant allele of GDF9 gene in the F1 generation population of Tan-Han sheep was A gene with a genotype frequency of 0.58. The SNP loci of BMP15 and GDF9 genes were in moderate polymorphism in the F1 population of Tan-Han cross, and the GDF9 gene was in Hardy-Weinberg equilibrium(P>0.05) in the F1 generation population of Tan-Han sheep. The AA genotypes of two genes, BMP15 and GDF9, had better lamb production than the AB and BB genotypes in the F1 generation population of Tan-Han sheep. The BMP15 genotypes AA and BB had a significantly higher lamb number of second litter than the AB genotype(P<0.05), and the AA genotype had a significantly higher lamb number of third litter than the AB and BB genotypes(P<0.05). The GDF9 genotypes AA and AB had a significantly higher lamb number of first litter than the BB genotype(P<0.05). There were 421 individuals of AA genotype of BMP15 gene and 315 individuals of AA genotype of GDF9 gene in the lactation cycle between 90 d and 150 d in the F1 generation of Tan-Han sheep, and the percentages were calculated to be higher than 50%. And the difference was significant(P<0.05) when compared with both AB and BB genotypes. The results indicated that polymorphic loci of BMP15 and GDF9 genes and AA genotypes had the potential to be molecular markers for improving reproductive traits in Tan-Han hybrid populations.