Evaluation of the association of SLC11A1 gene polymorphism with incidence of paratuberculosis in goats.

Paratuberculosis is one of the chronic granulomatous enteritis that predominantly affects ruminants world wide, caused by Mycobacterium avium ssp. paratuberculosis (MAP). In ruminants, microsatellite polymorphisms of the 3' untranslated region (3'UTR) of the solute carrier family 11 member A1 (SLC11A1) gene were associated with resistance to intracellular pathogen infections. This research was carried out to detect the polymorphisms in A and B regions of the 3'UTR of SLC11A1 gene and to evaluate the potential association between these polymorphisms and MAP infection in goats. MAP-specific antibodies were detected by ELISA and MAP infection was confirmed by IS900 PCR in 150 adult goats from different regions of Kerala, India. The polymorphism of microsatellite regions A and B at 3'UTR of the SLC11A1 gene was analysed in goats by an automated technique, fragment analysis, using fluorescent-tagged forward primers. Eight alleles with sizes ranging from 221 to 239 bp were found in region A. Region B revealed two alleles, 117 bp (B₇) and 119 bp (B₈). Animals with B₈ alleles were found to have higher incidence of paratuberculosis than animals with B₇ alleles (P < 0.01). There was no statistically significant association found between region A genotypes and paratuberculosis incidence. These results suggest that caprine SLC11A1 gene has significant role in paratuberculosis resistance in goats and further studies might help in development of a PCR-based genotyping test for paratuberculosis resistance and selection of superior animals for future goat breeding programmes.