The genetic stretch that undergoes mutation or alteration is called 677. The various changes are so similar that researchers think that evolution favors these specific variants. And it’s in a worrying place, said Vaughn Cooper, director of the Center for Evolutionary Biology and Medicine at the University of Pittsburgh School of Medicine, who worked on the study.
“This stretch of Spike is important because of its proximity to a key region for virulence,” Cooper told CNN by email.
“In fact, we think that these mutations are relatively rare (compared to other types of mutations), but are disproportionately selected when they occur,” he added.
The team has been reviewing genomic sequences deposited in GISAID, a global database that researchers are using to share genetic information about the virus. It is where scientists first noticed the emergence of new worrying variants, such as B.1.1.7, seen for the first time in the United Kingdom, and B.1.351, seen for the first time in South Africa.
“In late January 2021, our two independent genomic surveillance programs for SARS-CoV-2, based at the University of New Mexico Health Sciences in Albuquerque, New Mexico and the Louisiana State University Health Sciences Center in Shreveport, Louisiana, noticed numbers growing … virus carrying an S: Q677P mutation, and that this variant increased in frequency in samples collected in late 2020 through mid-January, “the researchers wrote.
This abbreviation – Q677P – refers to the specific change in the amino acid that makes up this part of the peak protein.
They identified seven similar mutations in 677 – each appearing to have appeared independently. They named them after birds to facilitate their identification.
One, called Robin 1, appeared in more than 30 U.S. states, predominantly in the Midwest, they said. A second “first appeared in an October 6, 2020 sample from Alabama and is named ‘Robin 2’ because of its similarity to the parental sub-lineage Robin 1,” they wrote. It is seen mainly in the Southeast. A so-called Pelican was first seen in a sample from Oregon and has since appeared in 12 other states, as well as Australia, Denmark, Sweden and India.
Pelican was the first variant that caught the researchers’ attention, in part because it was found in almost 28% of Louisiana samples and 11% of New Mexico samples.
“The remaining Q677H sub-strains contain about 100 sequences or less and are named: Yellowhammer, detected mainly in the southeastern United States; Bluebird, mainly in the northeastern United States; Quails, mainly in the southwest and northeast; and Mockingbird, mainly in the states the south-central and east coast, “wrote the research team.
The United States has barely studied the genomic sequences of circulating coronaviruses, so if these variants appeared so often in the databases, they are likely to be very prevalent, the researchers said. The appearance of so many similar mutations at the same time is “remarkable”, they said.
“These variants were not detected until mid-August 2020, but by February 3, 2021 they were already responsible for more than 2,327 of the 102,462 genomes deposited in the US GISAID,” they wrote. This deserves a lot of attention, they said.