Investigation of transferrin polymorphism in Garole sheep

摘要

The aim of this study was to determine the genetics of polymorph systems of Transferrin in Garole sheep breed. The present study was conducted on 95 adult Garole sheep comprising 52 ewes and 43 rams, maintained at Sheep and Goat Breeding Farm of West Bengal University of Animal and Fishery Sciences, West Bengal, during the period from April-September, 2009. The polymorphism of transferrin was determined through SDS-Polyacrylamide gel electrophoresis technique. It was found that the transferrin type was controlled by five codominant alleles (TfA, TfB, TfC TfD and TfE) in Garole sheep. These five alleles, because of co-dominant nature of inheritance, determined the occurrence of nine transferrin genotypes in the analyzed flock. Four (TfAA, TfBB, TfCC and TfDD) of these were homozygous and the remaining five (TfAD, TfBC, TfBD, TfCD and TfDE) heterozygous. It was found that the TfDD genotype (0.263) was predominant while TfDE genotype (0.042) was least common in the analyzed flock. Frequencies of other genotypes were as: TfCD(0.242), TfBD(0.126), TfCC(0.084), TfBB(0.074), TfAA(0.063), TfAD and TfBC (0.053 for each genotype ) in whole population. From the result it was found that in whole population combined, the heterozygotic genotypic frequency (0.516) was more than that of homozygotic genotypic frequency (0.484). Considerable variations were recognized in the frequencies of transferrin alleles. In the whole population frequencies of transferrin alleles were found to be TfA=0.089, TfB=0.163, TfC=0.232, TfD=0.495 and TfE=0.021. Transferrin system has shown an absence of genetic equilibrium among the analyzed herd (s2 value=51.31). In conclusion, there were polymorphism in Transferrin types and the presence of differences among the frequencies of the five alleles by categories could be a source of genetic variation in Garole sheep.