Genotypic and Sub-genotypic Diversity of Avian Paramyxoviruses 2, 4 and 6

Avian paramyxoviruses (APMVs) are contagious viruses infecting multiple avian species around the globe. Subsequent to evolution, the emergence of new strains is considered to cause outbreaks worldwide. Using standard classification criteria, genotypic and sub-genotypic distribution of strains within APMV-1 is much elucidated across the globe. Nevertheless, despite a growing number of genome sequencing data for APMVs excluding those that are prototypes, there is an absolute paucity of an updated unified phylogenetic classification scheme for APMV-2, 4, and 6. Utilizing a well-recognized genetic marker (complete fusion gene), genotyping and sub-genotyping of under-studied of APMVs strains was proposed by the implementation of different reliable tools and criteria. The analysis categorized the strains of each APMV-2 and 6 into two distinct genotypes (I and II), whereas APMV-4 strains categorized into three genotypes (I, II, and III). Additionally, a total of four sub-genotypes within APMV-6 (I.1, I.2, II.1, and II.2) and five sub-genotypes (I.1, I.2, II.1, II.2, and II.3) within APMV-4 were also proposed in the current study. Though it may require a revision and update in the future with the abundance of genome sequences and subsequent analysis from wide geography, herein the outcomes are relevant to better elucidate the classification and molecular epidemiology of study-included APMVs to depict an evolution and epidemiological link among outbreaks caused by field circulatory strains.