Fig. 1.

Schematic representation of 3a–c, E, and M genes of 21 of 32 lesional isolates from cats dying of FIP after being adopted from the SF SPCA shelter during 2008. Nineteen isolates have functional mutations in 3c, and two have intact 3c genes, but with nt substitution creating stop codon in 3a (SF-01) and a 3nt deletion in M (SF-18). The remaining 11 isolates with intact 3c had no functional mutations in any of these genes and were therefore not illustrated. ♦, nucleotide (nt) substitution creating stop codon. ▵, deletion mutation and # of nt deleted.