Did circoviruses intermediate the recombination between bat and pangolin coronaviruses, yielding SARS-CoV-2?

TL;DR

This study proposes a novel hypothesis that recombination between circoviruses and coronaviruses, specifically involving DNA and RNA viruses, may have contributed to the emergence of SARS-CoV-2, based on sequence similarities.

Contribution

It introduces a new hypothesis suggesting circoviruses may have recombined with coronaviruses, providing genomic evidence for a potential origin of SARS-CoV-2.

Findings

Sequence similarity between Bat-CoV ORF1a and PCV2 origin of replication.

Similar RNA secondary structures around the S gene cleavage site.

Evidence supporting possible recombination event leading to SARS-CoV-2 emergence.

Abstract

Since the first reports of a coronavirus (CoV) disease 2019 (COVID-19) caused by severe acute respiratory syndrome virus (SARS-CoV-2) in Wuhan, Hubei province, China, scientists are working around the clock to find sound answers to the issue of its origin. While the number of scientific articles on SARS-CoV-2 is increasing, there are still many gaps as to its origin. All studies failed to find a coronavirus in other animals that is more similar to human SARS-COV2 than the bat virus, considered to be the primary reservoir. In this paper we address a new hypothesis, based on a possible recombination between a DNA and SARS-CoV viruses, to explain the rise of SRAS-CoV-2. By comparing SARS-CoV-2 and related CoVs with circoviruses (CVs), we found strong sequence similarity of the genomic region at the 3-end of Bat-CoV ORF1a and the origin of replication (Ori) of porcine CV type 2 (PCV2), as well as similar RNA secondary structures of the region encompassing the cleavage site of CoV S gene with the PCV2 Ori. This constitutes a primary evidence that supports a possible recombination, which occurrence might explain the origin of SARS-CoV-2.