Forensic Genomic Analysis Determines That RaTG13 Was Likely Generated from a Bat Mating Plug

RaTG13 is phylogenomically the closest related coronavirus to SARS-CoV-2; consequently, understanding the provenance of this high-value genome sequence is important in understanding the origin of SARS-CoV-2. While RaTG13 was described as being generated from a Rhinolophus affinis fecal swab obtained from a mine in Mojiang, Yunnan, numerous investigators have pointed out that this is inconsistent with the low proportion of bacterial reads in the sequencing dataset. Metagenomic analysis confirms that only 10.3% of small-subunit (SSU) rRNA sequences in the dataset are bacterial, which is inconsistent with a fecal sample. In addition, the bacterial taxa present in the sample are shown to be inconsistent with fecal material. The assembly of mitochondrial SSU rRNA sequences in the dataset produces a sequence 98.7% identical to R. affinis mitochondrial SSU rRNA, indicating that the sample was generated from R. affinis or a closely related species. In addition, 87.5% of the reads in the dataset map to the Rhinolophus ferrumequinum genome, and 62.2% of these map to protein-coding genes, indicating that the dataset represents a Rhinolophus sp. transcriptome rather than a fecal swab sample. D