Authors

OA Agina¹; MS Rosly²; MI Nur Mahiza³; M Ajat³; M Zamri-Saad³; H Hazilawati³;  ¹ University of Nigeria, Nsukka, Nigeria;  ² Malaysian Agricultural Research and Development Institute, Malaysia;  ³ Universiti Putra Malasyia, Malaysia

Discussion

The bovine leukocyte antigen (BoLA) gene is a significant genetic part of the immune system and has been used as a disease marker in cattle. The 16SrRNA gene of Candidatus Mycoplasma haemobos was detected in 37 out of 85 (43.5%) Kedah-Kelantan x Brahman (KKB) cattle and allelic association of the BoLA-DRB3 gene to C. M. haemobos infection was evaluated. The association between an allele and T. orientalis were evaluated by Fisher’s exact and Cochran Mantel Haenszel (CMH) test. The odds ratios (OR) and their 95% confidence intervals for susceptibility or resistance were calculated for each allele. The amplification of the BoLA-DRB3 gene produced clear single bands of 281 bp by the single-step PCR analysis. Sequencing of the PCR amplicons yielded 279 - 320 nucleotides. The PCR-sequence based typing of BoLA-DRB3.2 gene from KKB cattle revealed that the gene is highly polymorphic. Ten novel alleles were detected (BoLA-DRB3*012:04, *015:08, *015:09, *015:11, *015:12, *017:05, *017:07, *024:33, *107:04, *168:01), and these alleles shared about 90.7-95.8% and 85-92% nucleotide and amino acid identities respectively, with the BoLA-DRB3*016:01 cDNA clone NR-1. Five alleles were detected in the C. Mycoplasma haemobos infected cattle namely: DRB3*012:01, *015:01, *007:01, *018:01, *009:02. The alleles with the highest frequencies were DRB3*009:02 (50%) and *007:01 (34.2%) in the C. Mycoplasma haemobos positive cattle and DRB3*018:01 (41.2%) and *015:01 (35.3%) in the C. Mycoplasma haemobos negative cattle. The associated alleles of C. Mycoplasma haemobos infection resistance was DRB3*007:01 (OR = 0.161; PCMH = 0.020) and *009:02 (OR = 0.084; PCMH = 0.000). No susceptibility alleles were detected following the Bonferroni correction of p-value, p > 0.0125. Therefore, we presented BoLA-DRB3.2 alleles associated with resistance to C. M. haemobos infection and suggests that during breeding, genetic selection of resistant animals could be a natural strategy for tick-borne disease control, particularly when there is no available global vaccine for the prevention and control of this infections. Keywords: bovine leukocyte antigen; alleles; Candidatus Mycoplasma haemobos; Kedah-Kelantan x Brahman cattle; PCR-Sequence based typing.