An Insect Nidovirus Emerging from a Primary Tropical Rainforest

Zirkel, Florian; Kurth, Andreas; Quan, Phenix-Lan; Briese, Thomas; Ellerbrok, Heinz; Pauli, Georg; Leendertz, Fabian H.; Lipkin, W. Ian; Ziebuhr, John; Drosten, Christian; Junglen, Sandra

Phylogenetic analyses reveal a novel cluster of insect nidoviruses. In order to identify the phylogenetic relationship of CAVV with other nidoviruses, we conducted phylogenetic analyses of protein alignments of conserved motifs within 3CL pro (ORF1a), RdRp, and HEL (ORF1b), as well as the putative structural S protein (Fig. 5) . In all phylogenies, CAVV branched from a deep node in the nidovirus tree above the Roniviridae family. In the ORF1b and S genes, CAVV had a most recent ancestor in common with the subfamilies Torovirinae and Coronavirinae. In 3CL pro , it branched from an ancestor it has in common with the subfamily Torovirinae. The low bootstrap support at this root point suggested that CAVV might also branch from an ancestor it has in common with Torovirinae and Coronavirinae. Although formal classification criteria for nidoviruses are not established, this phylogenetic positioning suggested CAVV to be a profoundly separated cluster of nidoviruses that might constitute a new family of nidoviruses with a phylogenetic position between Roniviridae and Coronaviridae on one side and Arteriviridae on the other.