Fig. 4. Phylogenetic tree based on the 5′-UTR comparison, showing taxonomic relationships of the CSFV strains in the Pestivirus genus. Strains Brescia (M31768), 39 (AF407339), Eystrup (AF326963), Alfort/187 (X87939), HCLV (AF091507), Shimen (AF092448), and the bovine strain 8 India (MG813566) are references for the genotype CSFV-a variant 1. Strains Alfort/Tuebingen (J04358), Chiba-80 (AB019659), Osaka/51 (AB019174), Paderborn (AY072924), and the Chinese bovine strains S173 (KF006975), HEN03 (KC176778), and S112 (MK118725) are references for the genotype CSFV-a variant 2. Strain Saitama/81 (AB019178) is the reference for the CSFV-a variant 3, and strains Parambi (KT239105), IND/AS/GHY/G4 (KM362426), and Honduras (L42426) are the references for the CSFV-a variants 4, 5, and 6, respectively. The Spanish ovine strain 5440/99 (AY159514) is the reference for the genotype CSFV-b. The Japanese strains Kanagawa/74 (AB019166) and Okinawa/86 (AB019172) are references for the genotype CSFV-c. The Chinese bovine strain S171 (KF006974) represents the genotype CSFV-d. Distances were computed using Clustal X, version 1.8, using the neighbor-joining method. Scale bar indicates 10 nucleotide substitutions per 100 nucleotides. Nomenclature of identified genotypes is based on divergence in the genus.