Members of this subfamily form a clade upon phylogenetic analysis (Figure 3.Arteriviridae). PLP1a is enzymatically inactive and, as a result, only a single nsp1 is produced in cells infected with equine arteritis virus. EAV also does not have nsp2TF or nsp2N ORFs produced by ribosomal frameshifting.
Genus demarcation criteria
There is only one genus in the subfamily. See “Subfamily, genus and species demarcation criteria” section on the family for species demarcation criteria which are universal for all subfamilies.