Molecular Analysis of Pathogenicity Differences of Avian Paramyxovirus 1 Genotypes VI and VII in Chickens

Abstract

Background: Genotypes VI and VII of (APMV-1) have different host range and pathogenicity in pigeons and chickens. However, the molecular determinants of these differences are still unclear. Methods: Here, we aligned the DNA sequences of 56 genotype VI and 33 genotype VII APMV-1 strains. Sequence alignment results revealed that there are 17 amino acids sites differed between APMV-1 strains of these two genotypes. We then constructed a plasmid based on the full-length genome of rSG10 APMV-1 strain, which belongs to genotype VII but was mutated with these 17 VI-genotype-specific amino acids, and rescued as rSG10-17 strain. The restriction digestion and ligation and overlapping PCR methods were used in the construction of plasmids with amino acids mutation. This virus was evaluated for its virulence and growth characteristics. Results and conclusion: The results indicated that the virulence and the growth characteristics have no obvious difference between the rSG10-17 virus and its parental strain rSG10. The simultaneous mutation of 17 genotype-specific amino acids did not affect the virulence of APMV-1 in chickens. Further analysis of these amino acids is required by taking into consideration of the functions of encoded proteins.