Genetic assessment of BoLA-DRB3 polymorphisms by comparing Bangladesh, Ethiopian, and Korean cattle
Attributable to their major function in pathogen recognition, the use of bovine leukocyte antigens (BoLA) as disease markers in immunological traits in cattle is well established. However, limited report exists on polymorphism of the BoLA g...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
Korean Society of Animal Sciences and Technology
2021-03-01
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Series: | Journal of Animal Science and Technology |
Subjects: | |
Online Access: | http://www.ejast.org/archive/view_article?pid=jast-63-2-248 |
Summary: | Attributable to their major function in pathogen recognition, the use of bovine
leukocyte antigens (BoLA) as disease markers in immunological traits in cattle
is well established. However, limited report exists on polymorphism of the BoLA
gene in zebu cattle breeds by high resolution typing methods. Thus, we used a
polymerase chain reaction sequence-based typing (PCR-SBT) method to sequence
exon 2 of the BoLA class II DRB3 gene from 100 animals (Boran, n = 13; Sheko, n
= 20; Fogera, n = 16; Horro, n = 19), Hanwoo cattle (n = 18) and Bangladesh Red
Chittagong zebu (n = 14). Out of the 59 detected alleles, 43 were already
deposited under the Immuno Polymorphism Database for major histocompatibility
complex (IPD-MHC) while 16 were unique to this study. Assessment of the level of
genetic variability at the population and sequence levels with genetic distance
in the breeds considered in this study showed that Zebu breeds had a gene
diversity score greater than 0.752, nucleotide diversity score greater than
0.152, and mean number of pairwise differences higher than 14, being very
comparable to those investigated for other cattle breeds. Regarding neutrality
tests analyzed, we investigated that all the breeds except Hanwoo had an excess
number of alleles and could be expected from a recent population expansion or
genetic hitchhiking. Howbeit, the observed heterozygosity was not significantly
(p < 0.05) higher than the expected heterozygosity.
The Hardy Weinberg equilibrium (HWE) analysis revealed non-significant excess of
heterozygote animals, indicative of plausible over-dominant selection. The
pairwise FST values suggested a low genetic variation among all the breeds (FST
= 0.056; p < 0.05), besides the rooting from the
evolutionary or domestication history of the cattle. No detached clade was
observed in the evolutionary divergence study of the BoLA-DRB3 gene, inferred
from the phylogenetic tree based on the maximum likelihood model. The
investigation herein indicated the clear differences in BoLA-DRB3 gene
variability between African and Asian cattle breeds. |
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ISSN: | 2672-0191 2055-0391 |