Genetic Polymorphism of CD18 gene in Karan Fries Young bull Calves using PCR-RFLP Analysis

CD18 gene encodes the common subunit of b₂ integrin molecules that are responsible for the leukocytes to migrate into the site of inflammation. Point mutation from adenine to guanine at 383 position of CD18 gene causes the loss of CD18 & CD11 subunits aggregation ability and which leads to the Bovine Leukocyte Adhesion Deficiency (BLAD) syndrome. BLAD is an autosomal recessive congenital disease of Holstein Friesian (HF) cattle breed and is characterized by recurrent bacterial infections, delayed wound healing, stunted growth and persistent marked neutrophilia. BLAD syndrome was spread throughout the world mainly by the use of semen from carrier animals in artificial insemination (AI) as they have viability. Use of HF bulls or their semen extensively for crossbreeding programmes during the last five decades made the screening of farm born HF and its crossbreds mandatory before their use in breeding programmes. In the present study, isolated genomic DNA from young Karan Fries bull calves was amplified and PCR products were subjected to RFLP analysis using Taq I restriction enzymes. Result indicated that out of 55 examined calves, 2 (3.64%) were BLAD carriers (BL/TL) and 1 (1.82%) was BLAD affected (BL/BL). This study has recommended the nation to screen all HF and its crosses across the country for BLAD.