Isolation,Identification and Molecular Evolution Analysis of F Gene of Pigeon Paramyxovirus Type 1 Isolated From Guangxi in 2019

In order to understand the sub-genotype and genetic variation of pigeon paramyxovirus type 1（PPMV-1） isolates in Guangxi, three strains of the virus were isolated from clinical samples suspected to be infected with PPMV-1 in Guangxi pigeon farms in 2019. The isolates were subjected to F gene sequencing, phylogenetic analysis and molecular clock phylogeny analysis. The results showed that 3 strains were isolated and identified from clinical samples and named Pi/CH/GX1101/2019, Pi/CH/GX1201/2019 and Pi/CH/GX1202/2019, respectively. Sequencing analysis of the isolates showed that F gene ORF length of strains was 1 662 nt coded 553 amino acids and the cleavage site of F protein was ¹¹²RRQKRF¹¹⁷, which possesses the virulent NDV molecular characteristics. The three isolates identified in this study were grouped into genotype Ⅵ. Phylogenetic analysis showed that the three strains belonged to two genotypes: sub-genotype Ⅵ.2.1.1.2.1（former Ⅵj genotype） and sub-genotype Ⅵ.2.1.1.2.2（former Ⅵk genotype）. The molecular clock phylogeny analysis showed that the Chinese sub-genotype Ⅵ.2.1.1.2.1 and Ⅵ.2.1.1.2.2 strains began to diverge evolutionarily around the 1980 s. Pi/CH/GX1201/2019 and Pi/CH/GX1202/2019（sub-genotype Ⅵ.2.1.1.2.1） were found to be more closely related to the low-nodal wild-bird-origin strain W4 in the same branch. The Pi/CH/GX1101/2019 strain（sub-genotype Ⅵ.2.1.1.2.2） was also found to be related to 2 wild-bird-origin strains（Grey heron/CH/GD/GZ333/2015 and European turtle dove/CH/GD/GZ23/2015） at the low node and in the same small cluster. The results of the study showed that Ⅵ.2.1.1.2.2 and Ⅵ.2.1.1.2.1 were the predominant sub-genotype circulating in pigeons in Guangxi and there was a presumed risk of wild bird isolates entering commercial pigeon populations.