FIG 1 .

Genome organization and replication of BtCoV HKU5-SE in Vero cells. (A) Schematic of the genome organization of BtCoV HKU5 (top) and the recombinant virus in which the S protein was replaced with the ectodomain of SARS S glycoprotein (SE, yellow). The asterisk indicates the Y436H substitution. The bottom panel represents cDNA fragments A to F encoding the genome, with the T7 start site, the poly(T) tract, and the BglI restriction sites flanking the fragments. (B and C) BtCoV HKU5-SE replication in Vero cells compared with the replication of MERS-CoV Hu/SA-N1/2012 (MERS-CoV SA 1) (B) and SARS-CoV (C). Vero cells were infected with BtCoV HKU5-SE, MERS-CoV, and SARS-CoV at the indicated MOIs. Supernatants were sampled in triplicate at the times indicated, and titers determined on Vero cells by plaque assay. Error bars indicate standard deviations (SD).