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  • Covid 19 myths have spread just about as quickly as the disease itself.


  • But one myth in particular just won't go away.


  • That SARS cov to the virus that causes Covid 19 isn't naturally occurring and was actually man made.


  • In fact, one substantial survey found that almost 30% of Americans believe that this virus came from a lab.


  • But scientists believe that they can confidently say that the virus wasn't created by humans, and the myth going around is nothing more than that.


  • A myth.


  • So how do they know with such certainty?


  • The key is in the virus's genetic code?


  • This is the genomic sequence for SARS Cov two.

    これは、SARS Cov 2のゲノム配列です。

  • It was decoded in January 2020 just weeks after the world started to learn of this novel coronavirus.


  • Each of those letters is a genetic building blocks known as a nucleotide, and when built up, they form an organism's genetic code, which we can use to understand them.


  • Each organism has a different code and a varying amount of nucleotides.


  • A human has about three billion of them, whereas a virus such as SARS COV two has about 30,000.

    人間が約30億個持っているのに対し、SARS COV 2などのウイルスは約3万個。

  • Your genetic sequence can give information about your hair, eye color, sex and lineage.


  • And just like your jeans give clues about who and where you come from.


  • Scientists can use a virus genome sequence to help explain where that virus originated as well.


  • An ancestry test for viruses, if you will.


  • We hummed in on the parts of the virus that we thought were unique, and it might play a role in the evolution of the virus, but also in the pathogenesis of it.


  • And a couple of things stood out pretty quickly when we started to compare with the other Corona viruses that have come before.


  • That's Robert Garry, a professor of microbiology and immunology at Tulane University.


  • Along with his colleagues, he used the virus sequence to try and understand where SARS cov two came from.

    彼は同僚とともに、ウイルスの配列を用いて、SARS cov 2がどこから来たのかを解明しようとしました。

  • They first looked at the virus's backbone.


  • That's the whole genomic structure unique to each virus.


  • Like a viral template simplified the backbone for SARS cov two, and it's 30,000 nucleotide looks a little bit like this.

    SARS cov 2のバックボーンを簡略化したウイルスのテンプレートのようなもので、3万ヌクレオチドで、ちょっとした形をしています。

  • Each section is responsible for a part of the virus.


  • For example, this one is responsible for the spike proteins you may have seen lining the virus shell, so it may not come as a surprise that to engineer a virus in a lab you would need to start with a backbone.


  • But to manufacture from scratch the backbone of a virus that can also cause disease is almost impossible.


  • I mean, people just don't know enough about what makes the virus pathogenic to be able to symbol that.


  • How do you pick amongst all the possibilities to get to that last little bit?


  • That's going to turn it into this world wide pathogen?


  • Which sequences do you think about to put in there?


  • Simply?


  • There is just not enough knowledge about how to make a new virus that would also cause significant devastation.


  • Like SARS.


  • COV two has so creating a new deadly backbone is pretty much impossible.


  • But there is another way.


  • The novel coronavirus could have been created in a lab and that would be using an existing virus backbone or genetic sequence as a starting point with a recycled backbone.


  • Two main methods could have been used to create the new virus.


  • They could have either quickly mutated it or added and deleted parts of the existing virus.


  • But additions and deletions and a virus leave a trace that can be pointed out pretty quickly, a little bit like removing a red brick from a wall and replacing it with a black brick.


  • This is exactly what Macek Bony, an associate professor at Penn State, looked for.

    ペンシルバニア州立大学の准教授であるMacek Bony氏が探したのは、まさにこの点でした。

  • You might see an insertion that looks unusual, and you look out in nature and you see that no other viruses have genetic insertions like that.


  • We did not see any genetic insertions that not also identified in nature, so there's no evidence suggesting that it was man made or laboratory created somehow.


  • So what if they went with the other option and mutated an existing virus?


  • This is known as serial passage and acts in a similar way to selective breeding.


  • Scientists are able to mimic evolution to a degree by forcing the virus to mutate over and over again into a potentially different form.


  • This can be used to weaken a virus, which is how some vaccines have been made, or to strengthen a virus, say, by making it more transmissible.


  • But for this to work, the existing virus would have to show significant genetic similarity to the new virus.


  • In fact, they would have to be almost identical because this process only speeds up viral evolution and has a limit.


  • It's not possible to direct mutations into a completely different form.


  • Yet Gary and his team found that the backbone for SARS cov two was strictly unique, differing significantly from other Corona viruses.

    しかし、ゲイリーの研究チームは、SARS cov 2のバックボーンが厳密に独自のものであり、他のコロナウイルスとは大きく異なることを発見した。

  • For example, SARS cov the first Stars has only about a 79% genetic sequence match to SARS cov two.

    例えば、SARS cov the first Starsは、SARS cov twoと遺伝子配列が約79%しか一致していない。

  • So it's ruled out the best candidate is R 80 g 13, a bat coronavirus with a 96% gene sequence.

    そのため、遺伝子配列が96%のコウモリのコロナウイルスであるR 80 g 13が最有力候補であると断定されました。

  • Similarity 96% sounds pretty close, but in genetic terms, that's actually pretty long ways away.


  • To put it in perspective, humans and chimpanzees share 99% of the same genome, and you may have noticed there's still a large difference between the two for SARS cov two and R 80 g 13.

    因みに、人間とチンパンジーは99%のゲノムを共有していますが、SARS cov 2とR 80 g 13では、両者にまだ大きな差があることにお気づきでしょうか。

  • That 4% is the difference of about 800 nucleotides, or about 50 years of natural evolution.


  • 800 is too big a barrier.


  • You had something that was 99.5% or 99.7% similar.


  • Maybe only 20 or 30 nucleotides, you might get away with it.


  • You might be able to manufacture that doing the lab, but it just wouldn't be possible with current knowledge and existing viruses.


  • There's also another part of the gene sequence that helped Gary and his colleagues learn about the natural origins of sars-cov-2, in particular this set of nucleotides in the gene sequence.


  • You might remember those from earlier they're responsible for the virus spike proteins.


  • The pointy claw like arms lining the outside of the virus that give it its distinctive appearance and coronavirus is their name.


  • Specific viruses, including coronavirus, is use these arms to enter and take over host cells.


  • But this piece of the spike protein help tell the researchers that this virus originated in nature.


  • This set of nucleotides relates to the receptor binding domain, or RBD.

    この一連のヌクレオチドは、RBD(Receptor Binding Domain)に関するものです。

  • That's the part that latches onto the receptors on targeted cells as viruses can only survive when inside other cells.


  • This is a vital section that you would have to focus on if you were to make a virus in a lab, Gary and his team found.


  • The RBD has evolved specifically to bind to the human cell a C to a receptor usually used to help regulate blood pressure, but it's the way it's so successfully binds to the A C two receptor that is crucial.

    RBDは、通常は血圧を調整するために使用されるヒト細胞のa C to a受容体に結合するように特別に進化しましたが、A C 2受容体にうまく結合する方法が重要なのです。

  • You see, when a scientist tests what aspects would make a virus more potent, they run models through computer simulations.


  • But when researchers put this sequence through those simulations, they found that sars-cov-2 RBD shouldn't be successful at all.

    しかし、この配列をシミュレーションしてみると、「sars-cov-2 RBD」は全く成功しないはずであることがわかりました。

  • And what actually caused poor efficiency and transmission, which we know is not the case by working in the lab, working with computer, trying to figure it out.


  • I mean, they just would not have come up with this particular way to have this virus buying this receptor a very important part of the whole replication process.


  • In other words, if your goal was to make a virus to infect humans, you wouldn't have chosen this one.


  • Basically, what nature has been has come up with a solution for binding that is better than any computer and ultimately better than what any scientists could come up with.


  • So we know why.


  • Scientists confidently say Sars-cov-2 wasn't made in a lab.


  • But that's not the end of the story.


  • It's also been rumored that Sars-cov-2 was a known virus that was accidentally leaked from a lab now we can't say for certain this isn't the case, but it's highly unlikely.


  • For one, this virus wasn't sequenced before January 2020.


  • And if it was, the world would know because the Wuhan Institute of Virology was specifically looking for something like this.


  • In order to protect the world from any outbreaks, they would have come up with the SARS coronavirus.


  • That was 76% similar to the original stars.


  • One, I mean, they would have published that as fast as they could.


  • That would have been, at least in the scientific world, very big news.


  • But it's also just statistically highly unlikely.


  • So just that in nature, there literally beings of people that are having millions of encounters with these animals.


  • And, you know, we're talking about a handful.


  • A few dozen made in the whole world of scientists that go out and trap that.


  • So just on the odds of the things, that's just a minuscule chance that it was just one scientists that accidentally better themselves.


  • And that's very sophisticated laboratory setting.


  • So Sars-cov-2, whose origin is no longer a mystery but where and how it jumped in nature.


  • Well, that's a question many are still trying to answer.


  • Mhm.


Covid 19 myths have spread just about as quickly as the disease itself.



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コロナウイルスが研究室で作られたものではないことがわかる理由 (How We Know The Coronavirus Wasn’t Made In A Lab)

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    林宜悉 に公開 2021 年 03 月 25 日