Novel Variants of Avian Paramyxoviruses 13 in Wild Migratory Waterfowl Reveals 2 Low Evolutionary Rate

Abstract Avian paramyxovirus 13 (APMV-13), formerly known as Avian orthoavulavirus 13, is found scatteredly in wild birds around the world. Although four complete genome sequences of APMV-13 had been identified since the first discovery in Japan in 2003, the information available on the genetic variation and biological characteristics of APMV-13 is still limited. In the present study, we isolated six APMV-13 strians from fecal samples of wild migratory waterfowls during annual (2013-2018) viral surveillance of wild bird populations from wetland in China. The phylogenetic analyses showed that they had very close relationship in HN and F genes. The molecular clock estimations also showed a low evolutionary rate of APMV-13. However, there are obvious sequence differences among these strains. Bean goose/Hubei/V97-1/2015 is 1,953 nt in size (ORF, 1, 776 nt), which is a unique size and longer than other reported APMV-13 strians. Additionally, Swan goose/Hubei/VI49-1/2016 has four repeats of conserved sequences “AAAAAT” in the 5’-end trailer, which is unprecedented in the APMV-13. These findings reveal the existence of novel variants within APMV-13, which highlights the importance of continuous monitoring the specific species of APMVs.