Figure 2 GETV-V1 particle (black arrow) revealed by transmission electron microscopy (scale bar = 100 nm)
Excluding the poly(A) tail, the complete genome sequence of GETV-V1 was 11,689 nucleotides (nt) in length with a 5′-UTR of 78 nt and 3′-UTR of 402 nt (Table 1). The genome was similar to that of previously reported GETV strains. Sequence alignment of GETV-V1 with all GETV sequences available in GenBank revealed that GETV-V1 shared the highest identity (98.9%) with 16-I-674 (isolated from a horse in Japan in 2016), 98.1% identity with Chinese strains JL1707, JL1708, 12IH26 and Japanese strain 14-I-605-C2. Phylogenetic analysis showed that GETV-V1, together with HB0234, JL1707, JL1708, HNJZ-S1, HNJZ-S2 strains, was clustered into the Japanese GETV branch (Fig.3). Interestingly, although the Chinese reference strains were close to GETV-V1 geographically and temporally, they were phylogenetically much closer to each other, compared with GETV-V1. These results revealed that the GETV strains circulating in China are genetically diverse, thus providing a potential platform for evolution.
Table 1 Composition of genome and the encoded proteins of GETV-V1 strain