Study Of BMPR-IB And PGR Genes As The Candidate Genes For Fecunditiy Of Small Tail Han Sheep

Small Tail Han Sheep is a well-known Chinese breed for its fecundity and it is also known as a breed with higher fecundity and great variation in terms of prolificacy within population. Small Tail Sheep is an all-year-around reproduction sheep, which gives two births a year or three births in two years. The average lambing number per parturition is from 2 to 5 lambs and the lambing rate can be as high as 260%. To identifying the candidate genes for fecundity in Small Tail Sheep is of significance for its genetic utilization and the understanding of fecundity genes. In this research, there were 3 breeds of ewes being studied for BMPR-IB (Bone Morphogenetic Protein Receptor-IB,BMPR-IB ,FecB) and PGR ( Progesterone Receptor )Gene.Those 3 breeds are Small Tail Han sheep with high fecundity, Poll Dorset with medium fecundity and local Mongolia sheep with low fecundity.1 Study of the relationship beween the polymorphism of BMPR-IB gene and the reproductivity trait in Small Tail Han SheepThe DNA samples were purified from the blood samples taken from 33 Small Tail Han Sheep ewes in Shandong and 19 Poll Dorset ewes from Yongchang of Gansu, 14 Mongolia ewes from Wuwei of Gansu. The reproduction performance of the breeds was calculated for the study. BMPR-IB was used as candidate gene for the study of fecundity for Small Tail Han Sheep, and Australian Sheep Gene Mapping Web Site: AF298885 primer was used for PCR amplification and the genotypic analysis of the products from the PCR were analyzed by using Avall enzyme(Current study approved that the major gene responsible for high fecundity in Booroola sheep mainly results in the mutation of A→G taking place in the compiling region of gene BMPR-IB at the pair base of 746. Using a primer of AF298885 which is forced—PCR primer, the amplification of restricted piece of BMPR-IB gene was made, when the FecB presents, the pair base of A will mutate to G at the base pair of 746 in the compiling region of gene BMPR-IB. The product of PCR produces the cutting site for the enzyme of AvaII. The B Gene is the short term for FecB gene.). The results is in the following:(1) There are three genotypes of BB,B+,++ existing in Small Tail Han sheep. The frequency of the three genotypes are 0.3030, 0.6061 and 0.0909 respectvely. The mutated heterozygote of B+ and mutated homozygote BB are the dominant genotype among the all while wild-type ++ is the lowest in its gene frequency. For Poll Dorset sheep, the frequency of the three genotypes...