Extended ORF8 Gene Region Is Valuable in the Epidemiological Investigation of SARS-similar Coronavirus.

Severe acute respiratory syndrome Coronavirus (SARS-CoV) was discovered as a novel pathogen in the 2002-2003 SARS epidemic. The emergence and disappearance of this pathogen have brought questions regarding its source and evolution. Within the genome sequences of 281 SARS-CoVs, SARS-CoV-2, and SARSr-CoVs, a ~430 bp genomic region (from 27701bp to 28131bp in AY390556.1) with regular variations was investigated. This ~430 bp region overlaps with the ORF8 gene and is prone to deletions and nucleotide substitutions. Its complexity suggested the need for a new genotyping method for Coronavirus related to SARS-similar Coronavirus (SARS-CoV, SARSr-CoV and SARS-CoV-2). Bat SARSr-CoV presented three genotypes, of which Type 0 is only seen in Bat SARSr-CoV, Type I is present in SARS early phase and Type II is found in all SARS-CoV-2. This genotyping also shows potential usage in distinguishing the SARS-similar Coronaviruses from different hosts and geographic areas. This genomic region has important implications for predicting the epidemic trend and studying the evolution of Coronavirus.