Genetic studies on bovine leukocyte adhesion deficiency in Holstein Friesian crossbred cattle

Abstract

Bovine Leukocyte Adhesion Deficiency (BLAD) is a lethal autosomal recessive disorder and known to affect Holstein cattle breed throughout the world. In order to determine the area of mutation in CD 18 gene for BLAD, the PCR products of 367 bp were digested with Taq I endonuclease enzyme. After digestion of the PCR products, the normal BLAD allele in unaffected cattle produced two fragments of 313 bp and 54 bp. BLAD carriers exhibited three fragments of 367 bp, 313 bp and 54 bp; and the DNA of control affected cattle obtained from Department of Animal Genetics and Breeding, College of Veterinary Science and A.H., Anand Agricultural University exhibited only one fragment of 367 bp. The present study revealed two out of fifty Holstein cattle crosses were BLAD carriers. The DNA of the carriers of BLAD was sequenced by using ABI PRISM 310 Genetic Analyzer. Sequence obtained was deposited in NCBI (Accession number PBM17.sqn PBM17 KT032069). The genotype frequency of BLAD carriers was found to be 0.04. The gene frequency of dominant allele was estimated to 0.98 and that of recessive allele to 0.02. Out of fifty animals screened, 4% of animals were found to be heterozygous for BLAD.