Detection and screening of bovine leukocyte adhesion deficiency in Pakistan using molecular methods

Abstract

Bovine leukocyte adhesion deficiency (BLAD) is an autosomal recessive disease. Affected animals die because of extreme susceptibility to infections caused by the lack of a membrane glycoprotein called the leukocyte integrin beta-2 subunit of CD18. The present study was planned to standardize a technique for the diagnosis of BLAD and to get an estimation of BLAD allele in the Pakistani cattle population. The study was performed on 700 animals including Holstein-Friesian (HF) (n=280), Friesian-Sahiwal (FS) (n=120) Sahiwal (n=100) cows and HF calves (n=59) from Government as well as private farms. Similarly 141 bulls of Sahiwal (n=100), HF (n=18) and FS (n=23) from the Semen Production Unit Qadirabad and Kherimorat were also sampled. The identification of normal, carrier and affected animals were made by the PCR-RFLP method. No animal was found homozygous for BLAD while 10 animals including HF calve (n=1), FS bull (n=1), HF (n=6) and FS (n=2) cows were BLAD carrier. The Hardy-Weinberg frequency of the mutant allele in HF and FS population in Pakistan was calculated to 0.01. Thus there is a need of regular screening of the bulls used for artificial insemination to avoid the risk of spreading BLAD in the cattle population of Pakistan.

Incidence of bovine leukocyte adhesion deficiency, complex vertebral malformation, and deficiency of uridine-5-monophosphate synthase carriers in Brazilian Girolando cattle

“…This mutation causes a deficiency in a family of glycoproteins normally present on the surface of leukocytes, which normally allows them to move in the bloodstream. Leukocytes from affected individuals are unable to perform their biological functions; therefore, cattle with BLAD die at an early age due to complications from simple infections, pneumonia, tooth loss, and general impairment of the immune system (Nagahata, 2004;Nasreen et al, 2009;Riojas-Valdéz et al, 2009).…”

Identification of a null allele in genetic tests for bovine leukocyte adhesion deficiency in Pakistani Bos indicus × Bos taurus cattle

“…indicus null allele' in previously described BLAD tests [3,4,6] that caused the misdiagnosis of clinical normal animals as affected with BLAD occurs in high frequency in two Pakistani dairy breeds, the Cholistani (p ¼ 0.23) and Sahiwal (p ¼ 0.28) cattle, and in Sahiwal  Friesian cattle (p ¼ 0.3) but was not found among the purebred Friesian cattle. Using the modified PCR-RFLP the BLAD allele has been found in both purebred Friesian cattle and Sahiwal  Friesian cattle in Pakistan at a frequency of 0.01.…”

“…Using the BLAD test described by Nasreen et al [6] a clinically healthy crossbred AI bull (FS68) tested homozygous for the BLAD allele. Sequencing of the PCR product supported this finding and further investigations of a clinically healthy mature paternal half sibling FS15/1.4 showed similar test results.…”

“…These tests are based on PCR (using different primers) followed by TaqI and HaeIII restriction enzyme digests and electrophoresis (PCR-RFLP). The DNA test described by Nasreen et al [6] was used to genotype the BLAD locus in more than 700 Pakistani Bos taurus, Bos indicus and B. indicus  Bos taurus cattle and identified a clinically healthy mature bull that tested homozygous for the disease allele using the DNA tests described by Nasreen et al [6], Shuster et al [3] and Tammen et al [4]. Sequencing of the PCR product used for genotyping, supported the finding that the animal was homozygous for the disease mutation and further investigations showed that three mature related animals (half siblings with a common sire) also tested homozygous for the disease allele but did not present with pathognostic clinical signs consistent with BLAD.…”

Estimation of Cropped Area and Irrigation Water Requirement Using Remote Sensing and Gis

“…A number of inherited diseases afflicting buffaloes have been reported including: transverse hemimelia, arthrogryposis, dystocia, perosomus elumbus, umbilical hernia, schistosoma reflexus, hydrocephalus, polycephaly, etc. (Nasreen et al, 2009;Mehmood et al, 2014;Albarella et al, 2017). Despite the availability of these reports, comprehensive information on genetic disorders of buffalo breeds still needs to be made available.…”