A hidden gene in the novel coronavirus, which has claimed nearly 1.3 million lives globally, could be the reason behind its deadly pandemic potential. Researchers have discovered overlapping genes or “genes within genes” in the virus, which helps the virus replicate faster within host cells.
Scientists, including those from the American Museum of Natural History in the US, have come up with a new study where they said that knowing more about the 15 genes that make up the coronavirus could significantly help in developing drugs to combat Covid-19 in the future.
However, the study published in the journal eLife, also revealed how the overlapping genes make the SARS-CoV-2 potentially more dangerous than other similar coronaviruses.
The study’s lead author Chase Nelson from the American Museum of Natural History said the overlapping genes may be “one of an arsenal of ways in which coronaviruses have evolved to replicate efficiently, thwart host immunity, or get themselves transmitted.”
The new overlapping gene, ORF3D, in the SARS-CoV-2 has the potential to encode a protein that is longer than expected, said the research team after conducting the study.
They said that the overlapping gene is also present in a previously discovered pangolin coronavirus and suggested that the gene may have undergone changes during the evolution of SARS-Cov-2 and related viruses.
The study further said that ORF3D has been independently identified and elicited a strong antibody response in Covid-19 patients. As per the study, this demonstrates that the protein produced from the new gene is manufactured during human infection.
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Nelson said in the study that it is not yet clear if there is any clinical significance in the discovery, but suggested that the gene is “relatively unlikely to be detected by the T-cell response, in contrast to the antibody response”.
“And maybe that has something to do with how the gene was able to arise,” Nelson said.
The study also mentioned that overlapping genes are hard to spot and most scientific computer programs are not designed to find them. The researchers added that this structure is common in viruses.
According to them, this is partly because RNA viruses have a high mutation rate and tend to keep their gene count low to prevent a large number of mutations.
The scientists also noted in the study that the viruses have evolved a sort of data compression system in which one letter in its genome can contribute to two or even three different genes. “Missing overlapping genes puts us in peril of overlooking important aspects of viral biology,” said Nelson.
He also added that in terms of genome size, SARS-CoV-2 and its relatives are among the longest RNA viruses. This makes the novel coronavirus more dangerous than other RNA viruses.
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