Feline panleukopenia virus (FPLV) is the primary causative agent of a highly contagious and often fatal disease affecting domestic cats and other felids. The increasing isolation of species-specific FPLV variants from multiple host species has garnered considerable attention, highlighting the need to investigate their genetic diversity. In this study, three FPLV isolates were obtained and phylogenetically classified into two distinct FPLV-China groups within separate clusters. Compared to the prototype FPLV (M38246.1), these isolates exhibited seven amino acid substitutions in the NS1 (n = 6) and VP2 (n = 1) proteins. Further analysis of 157 NS1 sequences and 947 VP2 sequences retrieved from the NCBI database revealed 113 and 479 synonymous substitutions and 71 and 279 non-synonymous substitutions, respectively. Notably, the majority of these substitutions occurred as single events (57% in NS1, 40/71; 55% in VP2, 153/279) or were present in no more than five FPLV sequences (23% in NS1, 16/71; 32% in VP2, 89/279). However, three non-synonymous substitutions in the NS1 protein (Ile443Val, His595Gln, and Val596Leu) were detected in more than half of the 157 sequences analyzed. In the VP2 protein, six non-synonymous substitutions (Ala91Ser, Thr101Ile, Val232Ile, Lys93Asn, Asp323Asn, and Val562Leu) were each found in 20 to 40 FPLV sequences. Furthermore, ten sites in the NS protein and 224 sites in the VP2 protein exhibited both synonymous and non-synonymous substitutions simultaneously. Additionally, 75 sites in VP2 harbored multiple non-synonymous substitutions. These findings provide valuable insights for future research on the genetic determinants and vaccine development of FPLV.
Ye et al. (Fri,) studied this question.