Figure 3. A) Feline coronavirus genome indicating PCR products obtained (bars). Structural proteins are shaded in dark gray; nonstructural proteins are shaded in light gray. B) Forward and reverse primers used to amplify virus segments are listed in 5′ → 3′ orientation. The number of source cats and cloned sequences generated from feline infectious peritonitis (FIP) cases and feline enteric coronavirus (FECV) asymptomatic cats are presented. Pol, polymerase; NSP, nonstructural protein; FIPV, feline infectious peritonitis virus.