Scientists have identified a new ¡°hidden¡± gene in SARS-CoV-2 that can lead to a deeper understanding of the novel virus. The newly discovered gene is being claimed to be the reason behind COVID-19¡¯s pandemic potential.
In a new study published in the journal eLife, a team of scientists has identified ORF3d as a new overlapping gene in SARS-CoV-2. Scientists say that the gene has the potential to encode a protein that is longer than expected by chance alone.
The study explains that the novel coronavirus only has around 15 genes in total. Knowing more about these genes as well as the overlapping genes (genes within genes) can possibly have a significant impact on how we fight the virus.
¡°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,¡± said lead author of the study Chase Nelson, a postdoctoral researcher at Academia Sinica in Taiwan and a visiting scientist at the American Museum of Natural History.
¡°Knowing that overlapping genes exist and how they function may reveal new avenues for coronavirus control, for example through antiviral drugs.¡±
In their study, the research team explains that ORF3d was also present in a previously discovered pangolin coronavirus. Based on this, the scientists postulate that the gene was repeatedly lost and found during the evolution of SARS-CoV-2.
Scientists also found that the ORF3d¡¯s protein is manufactured when the virus infects a human host. They based this on the strong antibody response exhibited by the gene in Covid-19 patients once it was independently identified.
¡°We don¡¯t yet know its function or if there¡¯s clinical significance,¡± Nelson said. ¡°But we predict this gene is relatively unlikely to be detected by a T-cell response, in contrast to the antibody response. And maybe that has something to do with how the gene was able to arise.¡±
The study explains that such overlapping genes are common in viruses but are hard to spot as most of the scientific computer programmes are not designed to find them.
The overlapping genes lead to a low gene count, thus helping RNA viruses to keep a low number of mutations, even with their high mutation rate.
¡°Missing overlapping genes puts us in peril of overlooking important aspects of viral biology,¡± Nelson explained. ¡°In terms of genome size, SARS-CoV-2 and its relatives are among the longest RNA viruses that exist. They are thus perhaps more prone to ¡®genomic trickery¡¯ than other RNA viruses.¡±
(With inputs from IANS)