Sequence characteristics of PCV. (A) Genomic characteristics. The unique sequence of PCV1, PCV2, PCV3, and PCV4 were labeled green, red, gray, and blue, respectively. The conserved motif was marked by yellow. (B) Amino acids sequence alignment of PCV Capsid. The amino acid sequence alignments were performed with an online tool (https://www.genome.jp/tools-bin/clustalw, accessed on 5 April 2022) and shown by Espript 3.0 (https://espript.ibcp.fr/ESPript/cgi-bin/ESPript.cgi, accessed on 5 April 2022). The NLSs of Cap protein were predicted with NLStradamus (https://www.novopro.cn/tools/nls-signal-prediction.html, accessed on 5 April 2022). Moreover, loop regions of Cap protein were predicted with SOPMA (https://npsa-prabi.ibcp.fr/cgi-bin/npsa_automat.pl?page=/NPSA/npsa_sopma.html, accessed on 5 April 2022).