Cloning, sequencing and linkage mapping of the NRAMP1 gene of sheep and deer

The ovine NRAMP1 and cervine NRAMP1 cDNAs were cloned by RT PCR of RNA derived from macrophage enriched leukocyte preparations. The complete coding and 3' regions were sequenced. Both sheep and deer NRAMP1 proteins are 548 amino acids long. There are 77 and 73 amino acid differences, respectively, compared to the mouse Nramp1 sequence. Dinucleotide repeats were found in both the ovine and cervine 3' non-coding sequence. Amplification of these regions in individual sheep and deer showed them to be polymorphic micro-satellites. They have polymorphism information content values of 0·76 and 0·84 in sheep and deer, respectively. Using these microsatellites, the ovine NRAMP1 gene was mapped in a linkage group on ovine chromosome 2q and cervine NRAMP1 was mapped in a linkage group syntenic with human chromosome 2, mouse chromosome 1 and sheep chromosome 2.