Nyamiviridae: proposal for a new family in the order Mononegavirales

Abstract

Nyamanini virus (NYMV) and Midway virus (MIDWV) are unclassified tick-borne agents that infect land birds and seabirds, respectively. The recent molecular characterization of both viruses confirmed their already known close serological relationship and revealed them to be nonsegmented, single- and negative-stranded RNA viruses that are clearly related to, but quite distinct from, members of the order Mononegavirales (bornaviruses, filoviruses, paramyxoviruses, and rhabdoviruses). A third agent, soybean cyst nematode virus 1 (SbCNV-1, previously named soybean cyst nematode nyavirus), was recently found to be an additional member of this new virus group. Here, we review the current knowledge about all three viruses and propose classifying them as members of a new mononegaviral family, Nyamiviridae.

Fig. 1

Phylogenetic relationship of NYMV, MIDWV, and SbCNV-1 to other mononegaviruses. A maximum-likelihood tree was constructed using PhyML 3.0 (http://www.atgc-montpellier.fr/phyml/) based on a multiple amino acid sequence alignment of the RdRp polymerase core module as described previously [34]. Virus names and GenBank/RefSeq accession numbers: bornaviruses - Borna disease virus (BDV; NP_042024), avian bornavirus genotype 2 (ABV2; ADU05398); filoviruses - Sudan virus (SUDV; YP_138527), Marburg virus (MARV; YP_001531159); paramyxoviruses - Newcastle disease virus (NDV; NP_071471), Hendra virus (HeV; NP_047113), measles virus (MeV; NP_056924), Sendai virus (SeV; NP_056879), mumps virus (MuV; NP_054714), avian metapneumovirus (AMPV; YP_443845), human respiratory syncytial virus (HRSV; NP_056866); rhabdoviruses - rabies virus (RABV; NP_056797), bovine ephemeral fever virus (BEFV; NP_065409), vesicular stomatitis Indiana virus (VSIV; NP_041716), infectious hematopoietic necrosis virus (IHNV; NP_042681), potato yellow dwarf virus (PYDV; YP_004927971), lettuce necrotic yellows virus (LNYV; YP_425092); nyamiviruses - Nyamanini virus (NYMV; YP_002905337), Midway virus (MIDWV; YP_002905331), soybean cyst nematode virus 1 (SbCNV-1; AEF56729). Obtained and aligned partial or fragment sequences are depicted in boxes. Mononegavirus L-like protein sequences (MLLSs) in pea powdery mildew fungus (Erysiphe pisi) (EpMLLS), yellow fever mosquito (Aedes aegypti) (AaMLLS), zebrafish (Danio rerio) (DrMLLS); nyamivirus L-like protein sequences (NLLSs) in lettuce (Lactuca sativa) (LsNLLS), silkworm (Bombyx mori) (BmNLLS), leafcutter bee (Megachile rotundata) (MrNLLS), black carpenter and fire ants (Camponotus pennsylvanicus and Solenopsis invicta) (CfNLLS and SiNLLS); transcriptome shotgun assembly mononegavirus L-like protein sequences (ShTSA-L) in an ascomycete fungus causing dollar spot (Sclerotinia homoeocarpa) (ShTSA-L). Numbers at the nodes represent aLRT values derived using an SH-like calculation (only values greater than 0.7 are shown). Note that the zebra fish (Animalia: Chordata: Actinopterygii: Cypriniformes: Cyprinidae: Danio rerio Hamilton, 1822) sequence was first reported as another NLLS [4], but is has very poor sequence similarity (≈20 %) to MIDWV L and clusters more with MLLSs from fungi. The sequence is therefore listed as an MLLS (DrMLLS) in the figure