Polymorphism of acute-phase serum amyloid A isoforms and amyloid resistance in wild-type Mus musculus czech.

Until CE/J mice and their offspring were characterized as amyloid-resistant, all mice were thought to be amyloid-susceptible to multiple injections of azocasein or a single injection of silver nitrate following administration of amyloid enhancing factor. We now report, for the first time, that wild-type Mus musculus czech and F1 hybrids bred by crossing M. musculus czech with amyloid-susceptible CBA/J mice are also amyloid resistant. Based on the derived amino acid sequences of two serum amyloid A (SAA) cDNA clones, we describe two unusual SAA gene isoforms in M. musculus czech, one of which differs from four previously characterized acute-phase apoSAA isoforms at several amino acid residues. Our findings support the hypothesis that protection against amyloid fibril formation in wild-type M. musculus czech mice and their offspring is linked to apoSAA gene mutations (molecular motif).