The novel coronavirus lineage may have been circulating in bats for decades

Reporter : Zhang Jiawei

Publisher : XinhuaNet, via ScienceNet

Ref : http://news.sciencenet.cn/htmlnews/2020/7/443429.shtm

Translation, editing : Gan Yung Chyan

                                 / KUCINTA SETIA

 

An international team published a report in the British journal Nature Microbiology on 28 July 2020 that the novel coronavirus SARS-CoV-2 may have diverged from the bat coronavirus that is most closely related to it 40 to 70 years ago. This means that the virus lineage that produces covi may have been circulating in bats for decades.

It is difficult to understand the evolutionary history of the novel coronavirus in depth, because different viruses exchange genetic material and recombine, and subregions of the viral genome may originate from different ancestors. Existing studies have identified the bat coronavirus RaTG13 as the virus most closely related to SARS-CoV-2, and some studies have found similar coronaviruses in pangolins.

Researchers from Pennsylvania State University in the United States, the University of Edinburgh in the United Kingdom, and the University of Hong Kong in China analyzed the evolutionary history of the novel coronavirus based on the genome data of the B coronavirus branch B (coronavirus subgenus to which the novel coronavirus belongs).

The researchers used three methods to identify areas of the novel coronavirus that have not undergone recombination and that can be used to reconstruct the evolution of the virus. All methods show that RaTG13 and SARS-CoV-2 share a single ancestral lineage. It is estimated that the novel coronavirus differentiated from the bat coronavirus in the B coronavirus branch B in 1948, 1969 and 1982, respectively.

The study also concluded that although the novel coronavirus and related viruses carried by pangolins share a common ancestor, and pangolins may have played a role in the transmission of SARS-CoV-2 from animals to humans, pangolins are unlikely to be the cause and immediate host of SARS-CoV-2.

Researchers believe that the long differentiation time of SARS-CoV-2 indicates that there may be an unsampled, potentially infectious bat coronavirus lineage. At the same time, the existing diversity and dynamic process of virus recombination in the bat coronavirus lineage proves that it is quite difficult to identify viruses that may cause major human epidemics in advance.

The report’s corresponding author and Pennsylvania State University’s expert Maciej F. Boni pointed out that relevant parties need to establish an extensive, real-time surveillance system to detect coronaviruses like SARS-CoV-2 in time when the number of infections is still at a low level.

Ref : Maciej F. Boni etal., Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID-19 pandemic, Nature Microbiology, https://www.nature.com/articles/s41564-020-0771-4