The family of SARS - CoV-2 , the virus creditworthy for the Covid-19 pandemic , has been lounge in the squash racquet caves of China for decennium and most likely include other relatives that could infect humans . That ’s harmonize to a new survey published in the journalNature Microbiologythis week .
An international team of scientists from the UK , Belgium , China , and the US traced the evolutionary account of SARS - CoV-2 by canvass genetically come to coronaviruses found in bats and pangolin . Understanding the evolutionary origins of the novel coronavirus can be fiddly as they undergo a cognitive operation make love asrecombination , in which two different viruses both infect the same emcee cellular telephone and interact during replication , resulting in hereditary material being swapped . This means their genome does not have a straight - forward ancestry and can come from multiple sources .
According to the new finding , the lineage of virus to which SARS - CoV-2 belongs to genetically is split between related bat coronaviruses that depart in 1948 , 1969 , and 1982 . One of these divergences , in 1969 , eventually dedicate hike to RaTG13 , a coronavirus that’s96.1 percent genetically similarto SARS - CoV-2 . Researchers first identified this virus in 2013 after try ahorseshoe chiropteran in China ’s Yunnan province .
Another key feature analyzed by the researchers was the sensory receptor - binding domain ( RBD ) on the computer virus ’ spike protein , an important part of the virus that ’s effectively the “ key ” used by the pathogen to realize and get in host cells . The researchers found that SARS - CoV-2 and its relatives — such as RaTG13 and a pangolin virus try out in Guangdong in 2019 , Pangolin-2019 — all share a exchangeable RBD and spike protein . However , these features do not come out to be the merchandise of recombination . This hint the protein and its RBD are an patrimonial trait of the lineage leading to SARS - CoV-2 , RaTG13 , and Pangolin-2019 .
It also hints that there could be other members of this family that are capable of infecting world .
“ This means that other viruses that are subject of infecting humankind are distribute in shoe at-bat in China , ” David L Robertson , cogitation author and professor of computational virology at MRC - University of Glasgow Centre for Virus Research , explain in astatement .
The finding also drop dubiety onthe hypothesis that pangolins , scaly - skinned mammals from Asia and Africa , were the intermediary animate being that harbored the virus before it jumped to humans . Previous research suggested SARS - CoV-2 ’s RBD chronological sequence was more similar to pangolin viruses than RaTG13 . However , the team found there was no grounds that pangolins help to arm SARS - CoV-2 with the RBD during its evolutionary history . Although pangolin may have played a role in the transmission to humans , they are unbelievable to be the chief average horde for the virus .
The report also highlights a last damning question : if these potentially baneful computer virus have been circulating in bats for tenner , then why did the Covid-19 pandemic catch the world off sentry duty ? To protect against the next coronavirus pandemic , the written report authors say their findings further highlight how the domain must carry out more enquiry and surveillance to name fresh pathogen .
“ We were too late in responding to the initial SARS - CoV-2 outbreak , but this will not be our last coronavirus pandemic . A much more comprehensive and veridical - clock time surveillance system needs to be put in place to catch virus like this when case numbers are still in the threefold digits , ” added Maciej Boni , report author and associate professor of biology at Penn State University .
