Scientists recently claimed that the presence of a specific genetic sequence known as CGG-CGG is an indication that COVID-19 originated in a laboratory.
According to a SciTechDaily report, the theory that COVID-19 was stimulated by the SARS-CoV-2 virus, being leaked from the Wuhan Institute of Virology in China was recently given new life after a controversial article in the Wall Street Journal in which the writers claimed the most captivating reason to favor the lab leak theory is strongly based in science.
Understanding a viral outbreak's origin can offer scientists vital information about viral lineages and enable steps to be put in place to prevent similar outbreaks in the future.
As such, the origin of the virus has been argued from the start of the pandemic and stays an active topic of discussion among researchers.
ALSO READ: COVID-19 Origin: Did Virus Escape from Lab or a Natural Emergence?
Scientists recently claimed that the presence of a specific genetic sequence known as CGG-CGG, is an indication that COVID-19 originated in a laboratory.
'Genetic Fingerprints'
For quite some time now, it has been known that viruses akin to the original SARS-CoV that results in SARS are discovered in bats. These viruses, this report specified, are well examined in China, where the 2002 SARS outbreak originally came from. However, related viruses have been discovered worldwide, a National Library of Medicine report said.
Expectedly, coronaviruses are involved again in a pandemic, the third such occurrence in the 21st century with SARS as the first, MERS, the second, and not the third, COVID-19.
While natural origin appears likely, and many have long cautioned about the danger of wildlife spreading viruses, scientists should not jump to conclusions.
One essential way scientists can identify the origin of a virus is by studying its genome. In the said WSJ piece, authors, astrophysicist Professor Richard Muller, and physician and Atossa Therapeutics chief executive Dr. Steven Quay claimed COVID-19 has "genetic fingerprints" of a lab-origin virus.
For the claims being made to be further understood, genetic code needs to be understood. When a virus is infecting a cell, it hijacks the cellular tools, offering instructions or genome to generate more copies of itself.
Nucleotides
The genome is composed of a long series of molecules identified as nucleotides, each of which, represented by the letters A, C, G, or U.
Essentially, a group of three nucleotides identified as a codon provides the instruction for a cell to produce an amino acid, the most fundamental molecular building block of living things.
Most of these amino acids are encoded by many different codons. CGG in particular is one of the six probable codons instructing the cell to contribute to amino acid arginine.
The article writers have argued that SARS-CoV-2 originated in a laboratory-based on the presence of a CGG-CGG sequence.
Additionally, the authors also claimed this is a readily available and convenient codon pair that researchers opt to use to generate the amino acid arginine.
Nonetheless, for anyone who has an understanding of the approaches necessitated for genetic modification, this double-CGG is typically no more difficult or easy to yield compared to any other codon pair that encodes arginines.
No Reason for Natural Existence of Double CGG
The article writers claim too, that the CGG codon appears less often compared to the other five possible codons in betacoronaviruses, the coronavirus family to which SARS-CoV-2 belongs.
They said, if one is to look at related coronaviruses, the CGG codon is encoding approximately five percent of all arginines in SARS-CoV compared with roughly three percent of all arginines in SARS-CoV-2.
Even though CGG is less typical compared to other codons, the argument of the authors fails to offer a reason that the double-CGG sequence could not naturally exist.
The authors have contended that recombination, when viruses infecting the same host, is sharing genetic material, was the most possible way in which COVID-19 was able to obtain the double-CGG sequence.
The authors noted too that the double-CGG codon pair does not exist in other members of this coronavirus type, so natural recombination could not potentially yield a double-CGG.
Nevertheless, viruses are not reliant on preassembled segments of genetic material to evolve, not to mention expand their host range.
COVID-19 Origin May Remain Unresolved
Scientists' final claim that the initial sequenced SARS-CoV-2 virus was perfectly suited to the human host abandons evidence of viral spread in local productions of animals, animal-to-animal spread, as indicated in the Nature journal, and the quick evolution that is driving the rising transmissibility of the newer strains.
Lastly, disappointingly, a lot of other media articles seem to have accepted and repeated the claims from the WSJ article. The origin of COVID-19 may remain unresolved, although there is no proof presented in the said article that scientifically backs the idea of a lab leak of the genetically engineered virus.
A related report is shown on The Economist's YouTube video below:
RELATED ARTICLE: COVID-19 Leak in Wuhan Lab Possible; Scientist Who Worked at WIV Breaks Her Silence
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