Complete genome sequences of porcine circovirus-like virus P1 mutants with 163 amino acids in the capsid protein.

Porcine circovirus-like virus P1 is a novel circovirus that was originally detected in China in 2005. Here, we report the genome sequences of P1 isolates JS02, JS03, and HuN06, each with 163 amino acids in its capsid protein. The complete genome of each of these isolates contains 649 nucleotides and has a T insertion at position 207. Phylogenetic analysis based on complete genome sequences of 18 P1 reference strains grouped 16 P1 sequences from this study into one cluster, with the JS02, JS03, and HuN06 isolates forming an independent clade. However, phylogenetic analysis based on amino acid sequences of the capsid protein showed that the JS02, JS03, and HuN06 strains were on the same large branch with PCV2, distinct from other P1 isolates. These results help us to understand the origin and evolution of P1.