Screening for bovine leukocyte adhesion deficiency (BLAD) in Vechur cattle

Abstract

The vechur cattle of Kerala were screened for the presence of the bovine leukocyte adhesion deficiency (BLAD) genetic defect using the PCR-RFLP and DNA sequencing methods. Vechur animals (129) of either sex, were used for this study. A159 bp fragment enclosing the polymorphic HaeIII site for point mutation 01280 within the fifth exon of the CD18 gene was amplified by specific primers. The digestion of the PCR product with HaeIII enzyme revealed fragment patterns corresponding to the normal allele and none of the animals was found to carry the BLAD allele. The results were further confirmed by direct sequencing of5 randomly selected PCR products. The BLASTn search at the NCBI site revealed 100% sequence homology of the query sequence with the corresponding sequence of the Bas taurus CD18 gene. The PCR-RFLP method used for screening the Vechur cattle for BLAD defect was very handy and reliable.