Molecular cloning of canine mucosal addressin cell adhesion molecule-1 cDNA and its expression in normal tissues

A cDNA encoding canine mucosal addressin cell adhesion molecule-1 (MAdCAM-1) was cloned. The entire open reading frame of canine MAdCAM-1 cDNA comprises 1137 bp, corresponding to 378 amino acid residues. The deduced amino acid sequence of canine MAdCAM-1 was 55.2%, 53.7%, and 52.4% identical to rat, mouse, and human MAdCAM-1, respectively. Canine MAdCAM-1 appeared to contain two immunoglobulin-like domains at the N-terminus, followed by a mucin-like domain and a third immunoglobulin-like domain. The structures of the dog, rat, and mouse proteins are likely similar because all of the cysteine residues in the immunoglobulin-like domains were conserved. Canine MAdCAM-1 mRNA was confirmed to express extremely in the mesenteric lymph node by RT-PCR.