鲁中肉羊育种中FecB突变应用效果分析

Analysis of the Application Effects of FecB Mutation in Breeding of Luzhong Mutton Sheep

为评价FecB突变在鲁中肉羊培育中的应用效果,本研究首先利用TaqMan探针高通量分型技术对2295只鲁中肉羊FecB基因进行分型,统计FecB基因在鲁中肉羊群体中的分布情况,然后结合253只母羊的产羔数据和865只初生羔羊、83只3月龄母羔羊的体尺体重数据分析FecB基因对鲁中肉羊产羔数和早期生长发育的影响。群体遗传学分析表明:鲁中肉羊群体存在AA(++)、AG(B+)和GG(BB)3种FecB基因型,在新品种培育过程中突变纯合子频率逐年增加,且表现为中度多态性(0.25<多态信息含量<0.5);卡方适合性检验发现,FecB突变位点向Hardy-Weinberg平衡状态(P>0.05)转变;BB型母羊平均产羔数高于++型(P<0.01);BB型初生羔羊的体重低于++型(P<0.01),BB型初生公羔的体高、胸围、胸宽、胸深和初生母羔的胸深和管围低于++型(P<0.05),B+型3月龄母羔的管围低于++型(P<0.05)。结果显示,FecB突变显著提高了鲁中肉羊的产羔数,但对初生羔羊的生长发育存在一定的逆增长效应。

The aim of this study was to evaluate the application effects of FecB mutation in the breeding of Luzhong mutton sheep. High-throughput genotyping technique using TaqMan probe was used to calculate the distribution of FecB gene in 2 295 Luzhong mutton sheep, and then the lambing data of 253 ewes and the records of body size and body weight of 865 newborn lambs and 83 3-month-old female lambs were used to analyze the effects of FecB on litter size and early growth and development of Luzhong mutton sheep. Population genetic analysis showed that there were 3 FecB genotypes in the Luzhong mutton sheep, frequency of FecB mutation homozygote increased year by year in the breeding of Luzhong mutton sheep, and the FecB mutation site had moderate polymorphism(0.25<PIC<0.5). The test for goodness of fit showed that the FecB mutation site changed to Hardy-Weinberg equilibrium(P>0.05). Average litter size of BB ewes was significantly higher than ++ ewes(P<0.01). And body weight of BB lambs was prominently lower than ++ individuals(P<0.01). Compared with ++ type, body height, chest circumference, chest width and chest depth of BB newborn male lambs as well as chest depth and cannon bone circumference of BB newborn female lambs were remarkably lower(P<0.05). The cannon bone circumference of B+ 3-month-old female lambs was markedly lower than ++ animals(P<0.05). The results hinted that FecB mutation notably increased litter size of Luzhong mutton sheep, but had adverse effects on the growth and development of newborn lambs.