Abstract
Background: The Major Histocompatibility Complex (MHC), which codes for proteins essential to immune response, is frequently cited as a candidate gene associated with gastrointestinal parasite (GIP) resistance in small ruminants. This study aimed to investigate the polymorphism of the MHC-DRB gene in a crossbred Anglo-Nubian goat population and assess its association with GIP burden. Methods: Fecal analysis was conducted to estimate worm burden based on egg per gram (EPG) count. Sequence-based genotyping was used to analyze polymorphisms within the 285 bp fragment of the MHC-DRB gene exon 2. Results: The results confirmed high polymorphism of the MHC-DRB gene in goats, identifying 23 SNPs, 20 of which were non-synonymous mutations leading to 14 amino acid changes. Additionally, three Linkage Disequilibrium (LD) blocks and 21 closely linked SNP pairs (r² > 0.9) were identified. Conclusion: Association analysis revealed that individual SNPs, LD blocks, and SNP pairs were not significantly associated (p > 0.05) with worm burden. Thus, with the established significance of MHC in immune response mechanism it is recommended to conduct further investigation with larger sample sizes including different goat breeds. Additionally, it is recommended to explore other MHC loci and to associate the polymorphisms identified with other immune-related traits.
Keywords: MHC-DRB fragment, Non-synonymous mutations, Ruminants, Worm burden