[ExI] The Science Suggests a Wuhan Lab Leak
Bill Hibbard
hibbard at wisc.edu
Mon Jun 7 13:21:40 UTC 2021
https://www.wsj.com/articles/the-science-suggests-a-wuhan-lab-leak-11622995184
A genome is a blueprint for the factory of a cell to make proteins. The
language is made up of three-letter “words,” 64 in total, that represent
the 20 different amino acids. For example, there are six different words
for the amino acid arginine, the one that is often used in supercharging
viruses. Every cell has a different preference for which word it likes to
use most.
In the case of the gain-of-function supercharge, other sequences could
have been spliced into this same site. Instead of a CGG-CGG (known as
“double CGG”) that tells the protein factory to make two arginine amino
acids in a row, you’ll obtain equal lethality by splicing any one of 35 of
the other two-word combinations for double arginine. If the insertion
takes place naturally, say through recombination, then one of those 35
other sequences is far more likely to appear; CGG is rarely used in the
class of coronaviruses that can recombine with CoV-2.
In fact, in the entire class of coronaviruses that includes CoV-2, the
CGG-CGG combination has never been found naturally. That means the common
method of viruses picking up new skills, called recombination, cannot
operate here. A virus simply cannot pick up a sequence from another virus
if that sequence isn’t present in any other virus.
Although the double CGG is suppressed naturally, the opposite is true in
laboratory work. The insertion sequence of choice is the double CGG.
That’s because it is readily available and convenient, and scientists have
a great deal of experience inserting it. An additional advantage of the
double CGG sequence compared with the other 35 possible choices: It
creates a useful beacon that permits the scientists to track the insertion
in the laboratory.
Now the damning fact. It was this exact sequence that appears in CoV-2.
Proponents of zoonotic origin must explain why the novel coronavirus, when
it mutated or recombined, happened to pick its least favorite combination,
the double CGG. Why did it replicate the choice the lab’s gain-of-function
researchers would have made?
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