Polymorphisms of the slc11a1 gene in Creole goats: an initial study of natural resistance to paratuberculosis

Abstract

Paratuberculosis is a chronic bacterial infection caused by Mycobacterium avium subspecies paratuberculosis (MAP), which primarily affects sheep, cattle, and goats. It is characterized by progressive wasting of the animal until its complete decline. Controlling paratuberculosis relies on costly and difficult-to-implement measures; therefore, alternatives based on the host's genetic susceptibility to the pathogen are being explored. The Slc11a1 gene encodes a cation transporter protein located in the phagolysosome membrane of macrophages, which plays an active role in suppressing bacterial infections. The gene has a polymorphic microsatellite (GTN) in the 3' untranslated region (3'-UTR), and some of its alleles have been associated with natural resistance to pathogens such as Brucella and Mycobacterium in domestic animals. To demonstrate the presence of Slc11a1 polymorphisms in Creole goats, a PCR-SSCP analysis was performed on a 200 bp fragment corresponding to the 3´-UTR end. In the sample of 20 individuals, four electrophoretic patterns (215, 230, 245, and 265 bp) and three genotypes (215/215, 230/265, and 245/265) were obtained. Allele frequencies were 0.550 (215 bp), 0.100 (230 bp), 0.125 (245 bp), and 0.225 (265 bp). Genotypic frequencies were 0.55 (215/215), 0.20 (230/265), and 0.25 (245/265). The genotypes do not occur in population equilibrium (p>0.05). These preliminary results demonstrate several oliomorphisms of Slc11a1 and indicate the need to know their nucleotide sequences in order to identify favorable alleles that can be incorporated into paratuberculosis control and prevention programs in national goat herds through marker-assisted selection.