The Application Of Molecular Markers In Sheep Character Identification

The purpose of this study was mainly focused on the breeding of offsprings of Dorper×Hu sheep and Dorper×Han sheep by the technique of molecular marker analysis. Bone morphogenetic protein receptorⅠB (BMPR-ⅠB) gene which controls fecundity of sheep was selected as a candidate gene to evaluate the reproductive ability of these hybrid sheep. Polymorphisms of BMPR-ⅠB gene in Dorper sheep, Hu sheep, Han sheep, Dorper×Hu sheep and Dorper×Han sheep were detected by PCR-RFLP method. The results indicated that there was only one genotype (+ + ) in Dorper sheep, and BB genotype and B+genotype in Hu sheep and Han sheep. The genotype frequencies of BB and B+ in Hu sheep were 0.909 and 0.091, and 0.563 and 0.437 in Han sheep, respectively. Two genotypes (B+ and + + ) were found in the lambs of Dorper×Hu sheep and Dorper×Han sheep. The genotype frequencies of B+ and + +in Dorper×Hu sheep were 0.833 and 0.167, and 0.786 and 0.214 in Dorper×Han sheep, respectively. B + genotype primarily existed in Dorper×Hu sheep and Dorper×Han sheep. Through statistical analysis, the frequency of genotypes was not significantly different between Dorper×Hu sheep and Dorper×Han sheep (P>0.05) .The frequencies of genotypes were significantly different between Dorper sheep and Dorper×Hu sheep, Dorper sheep and Dorper×Han sheep (P<0. 01) .The results showed that reproductive ability of offsprings of Dorper×Hu sheep or Dorper×Han sheep could be improved by hybridization. The reproductive ability of Hu sheep and Han sheep could be transferred to offsprings by hybridization.BMPR-ⅠB gene could be used as a molecular genetic marker to select the litter size in sheep,could be used as a novel assistant technique for the selection of offsprings of Dorper×Hu sheep or Dorper×Han sheep. This could provide effective methods for evaluation and selection of high fecundity and high quality species of Dorper×Hu sheep or Dorper×Han sheep.