Study On The Correlation Between BMPR-IB Gene Polymorphism And Litter Size In Sheep Of Different Fertility

In order to investigate the genetic effects of Bone Morphogenetic Protein Receptor IB gene Coding region and Non-coding region polymorphisms on the reproductive performance of sheep,96 Multiple Hu Sheep(HM),65 Multiple Small Tail Han Sheep(SM),71 Twins Mongolian Sheep(MT),70 Singletons Mongolian Sheep(MS),52 Twins Oula Sheep(ZT),51 Singletons Oula Sheep(ZS),63 Twinns Gansu Alpine Fine-wool Sheep(GT),75 Singletons Gansu Alpine fine wool Sheep(GS),74 Singletons Duper Sheep(DS)and 51 Singletons Australian White Sheep(AS)were selected as research objects.PCR and DNA direct sequencing were used to detect SNPs in the Coding region and the partial 3' Non-coding region of the BMPR-IB gene in different fertility ewes,correlation analysis was conducted between polymorphism and its litter size.This study could lay a theoretical foundation for the discovery of molecular genetic markers of sheep double-lamb traits.The main findings are as follows:1.The polymorphisms were detected in the Coding region of BMPR-IB gene at 7 sheep varieties,and the results were found:(1)G/A mutation was detected at the 597 site of the coding region of the BMPR-IB gene.GA and AA genotypes were detected in HM.GG,GA and AA genotypes were detected in the other test groups.AA was the dominant genotype in HM and SM,A was the dominant allele,GA was the dominant genotype in MT,MS,ZT,ZS,GT and GS,G was the dominant allele.GG was the dominant genotype in DS and AS,G was the dominant allele.HM was in low polymorphism(PIC<0.25),and other experimental groups were in moderate polymorphism(0.25<PIC<0.5).In the Oula sheep test population,homozygous mutation AA genotype of litter size was significantly higher than wild GG genotype and heterozygous mutation GA genotype(P<0.05).In Mongolian sheep and Gansu alpine fine wool sheep test populations,different genotypes at this locus has no significant effect on their litter size(P>0.05).(2)A/G mutation was detected at the 746 site of the coding region of the BMPR-IB gene.B+ and BB genotypes were detected in HM.++,B+ and BB genotypes were detected in SM,MT and MS.++ and B+ genotypes were detected in GT,DS and AS.++ genotype was detected in ZT,ZS and GS.BB was the dominant genotype in HM,B+ was the dominant genotype in SM and G was the dominant allele.AA was the dominant genotype in the other experimental sheep and A was the dominant allele.SM was in moderate polymorphism(0.25<PIC<0.5),and other experimental groups were in low polymorphism(PIC<0.25).In Mongolian sheep and Gansu alpine fine wool sheep test populations,different genotypes at this locus has no significant effect on their litter size(P>0.05).(3)T/C mutation was detected at the 864 site of the coding region of the BMPR-IB gene.TT and TC genotypes were detected in HM,ZT and ZS.TT,TC and CC genotypes were detected in the other test groups.TT was the dominant genotype in HM,SM,MT,MS,ZT,ZS and DS,T was the dominant allele.TC was the dominant genotype in GT,GS and AS,T was the dominant allele.HM,MT,ZT,and ZS were in low polymorphism(PIC<0.25),and SM,MS,GT,GS,DS,and AS were in moderate polymorphism(0.25<PIC<0.5).In Mongolian sheep,Oula sheep and Gansu alpine fine wool sheep test populations,different genotypes at this locus has no significant effect on their litter size(P>0.05).(4)C/A mutation was detected at the 1113 site of the coding region of the BMPR-IB gene.CA and AA genotypes were detected in HM.CC,CA and AA genotypes were detected in the other test groups.AA was the dominant genotype in HM and ZT,A was the dominant allele.CA was the dominant genotype in SM,MT,MS,ZS,GT,GS,and AS.CC was the dominant genotype in DS.A was the dominant allele in SM,ZS,GT,GS and AS.C was the dominant allele in MT,MS and DS.HM was in a low polymorphism(PIC<0.25),and the other experimental groups were in a moderate polymorphism(0.25<PIC<0.5).In the Mongolian sheep,Oula sheep and Gansu alpine fine wool sheep test populations,different genotypes at this locus had no significant effect on their litter size(P>0.05).2.Fifteen polymorphisms were detected in the 1 bp-1425 bp region of the 3' Non-coding region of BMPR-IB gene at 7 sheep varieties.Among the A/G mutation was detected at the 1354 site of the 3' Non-coding region of the BMPR-IB gene,which is a close linkage disequilibrium relationship with the FecB gene.A single mutation at this site has a certain effect on the secondary structure of its mRNA.AG and GG genotypes were detected in HM.AA,AG and GG genotypes were detected in SM,MT,ZT and GT.AA and AG genotypes were detected in MS,ZS,GS,DS and AS.GG was the dominant genotype in HM and SM,G was the dominant allele.AA was the dominant genotype in MT,MS,ZS,GT,GS,DS and AS,A was the dominant allele.HM,MT,MS,ZS,GT,GS,DS and AS were in low polymorphism(PIC<0.25),SM and ZT were in moderate polymorphism(0.25<PIC<0.5).In Mongolian sheep test population,the homozygous mutant GG genotype of litter size was significantly higher than the wild AA genotype(P<0.05).In Oula sheep test population,homozygous mutant GG genotype and heterozygous mutant AG genotype of litter size were significantly higher than wild AA genotype(P<0.05).In Gansu alpine fine wool sheep test population,different genotypes at this locus had no significant effect on its litter size(P>0.05).