Researchers discovered a mysterious gene in the genome of the novel coronavirus, a sequence is formerly hidden from view deep inside of the gene segments, and usually overlooked until recently.
The new gene is known as ORF3d, and it’s a veritable example of what is known as an overlapping a gene, something of a “gene within a gene” that’s practically hidden inside a string of nucleotides, because of the way it gets to overlap the coded sequences of nearby genes.
Bioinformatician Chase Nelson of the American Museum of Natural History explained that, in terms of genome dimensions, 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,” Nelson added.
Viruses are naturally prone to hosting overlapping genes, so the discovery doesn’t necessarily come as a shocker.
It’s unclear yet if ORF3d represents genomic trickery, but it’s still difficult to see.
Hard To Find
Overlapping genes are hard to locate in genetic sequences because genomic scan systems can often overlook them when going through strings of gene code – coded to pick up individual genes, but not necessarily detecting overarching instructions standard between nucleotides of adjacent genes in a sequence.
In the context of viruses like the novel coronavirus, that may result in a severe blind spot. Scientists worked hard to find as much information about the virus as possible since early this year, and, while some aspects of its genetic composition were elucidated, a lot of information is still unknown.
“Missing overlapping genes puts us in peril of overlooking important aspects of viral biology,” Nelson stated.
Scientists are trying to find out what ORF3d is doing in the sequence where it’s locating, deep inside the genome and straddling other genes.