Name: 遺伝子の世紀：科学のクラッシュコースの歴史 #42 (The Century of the Gene: Crash Course History of Science #42)
Uploaded: 2021-01-14T10:30:18.000Z
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副詞形分詞節

largely addressed at the molecular level—and with companies setting up labs to test how thousands

of chemicals affect living things—and with new technologies like immortalized cell lines

and somatic-cell “cloning”—humanity could finally cure all disease and live forever…

Except that didn't happen, because—as usual—the natural world is a lot more complicated

Today, we'll tell the story of the Human Genome Project.

Epistemically, the amount of information contained

within even the smallest organism is simply mind-boggling.

Molecular biologists had figured out some genetic sequences in bacteria and the viruses

That seemed like mapping every star in the universe.

Technologically, scientists in the 1950s and 60s could barely sequence DNA and RNA at all.

One major breakthrough came in 1977, when British biochemist and double Nobel Prize

winner Frederick Sanger developed a new, reliable way of decoding DNA that became known as Sanger

Sanger's method became the standard way to sequence DNA until the late 1990s, when

“next-gen,” high-throughput sequencers became available.

It's complicated, but Sanger sequencing cleverly works by chopping up an unknown sequence

of DNA, tagging them with four different fluorescent dyes that bond to the four different nucleic

bases, and then sorting out the segments by length.

You can repeat the process many times to decode an entire genome.

One of the main issues is that decoding one sequence of DNA requires lots of copies of

And copying DNA, up until the 1980s, took lots of time.

Like… weeks to months, and it was expensive… and, even

Enter American biochemist and avid surfer Kary Mullis.

In 1983, while working at the biotech firm Cetus in California, Mullis developed polymerase

This was an automated way of taking advantage of a natural process for copying DNA.

In PCR, cycles of heating and cooling alternate between melting DNA and copying it using enzymes.

PCR can make billions of copies every hour, helping scientists quickly replicate strands

Mullis and his bosses published a paper on PCR in 1985, and he went on to win the Nobel

You could say Mullis didn't fit the mold of a traditional Nobelist.

For one, he admitted to using LSD frequently in his youth.

And—for a really weird two—in 1998, Mullis wrote an autobiography denying AIDS is a thing.

Modern science doesn't rely on individuals.

By the late 1980s, some biologists began to discuss what had seemed impossible a decade

before: completely decoding the human genome.

The stated idea was to understand the different versions of genes that seem linked to cancers

in order to develop better cancer-fighting drugs.

Another goal was political: this would be the Manhattan Project of biology.

The U.S. would fund the future of medicine and attract the top biologists… hopefully

Planning began in 1988, when the U.S. National Institutes of Health, or NIH, and the Department

And the federal government created the Office, later the Center, for Human Genome Research.

The Center's first director was the famous James Watson.

But he resigned early on, and physician and geneticist Francis S. Collins

Collins, by the way, has a rock band called The Directors!

The Human Genome Project officially began on October 1st, 1990, with the goal of sequencing

a representative “working draft” of ninety percent of a human genome—a model blueprint

There was no central hub: instead, many labs participated, all over the world.

But in 1996, DNA sequencing for the draft genome finally began at six U.S. universities.

So many geneticists began by sequencing related organisms.

In 1996, an international team finished a draft sequence of Saccharomyces cerevisiae

, the yeast humans use to make beer, bread, and biotechnologies.

Although Saccharomyces is a microbe, it was still the first eukaryotic organism—with

a membrane-bound nucleus, like humans!—to have its genome sequenced.

Also in 1996, scientists revealed a “map” of sixteen thousand human genes.

Critics thought HGP would be a gargantuan waste of money.

But the project was moving much faster than predicted.

In 1997, the Center became the National Human Genome Research Institute, or NHGRI.

And then, in 1998, American biotechnologist J. Craig Venter, entered the competition.

Earlier, Venter had worked at NIH, where he became an expert in making short synthetic

bits of DNA called "Expressed Sequence Tags."

These were useful for identifying genes…

And Venter and the NIH controversially tried to patent them.

The U.S. Patent and Trademark Office said no in 1992, but this battle introduced Venter

So later, when Venter disagreed with the manner in which HGP was being managed, he decided

That's right: one dude said, I'll beat the entire United States government at science!

Venter believed that HGP should switch from reliable but slow Sanger sequencing to a much

faster but more expensive new method called shotgun sequencing.!

Sanger sequencing only works on DNA strands up to ten thousand base pairs, which is very

“Shotgunning” a genome involves fragmenting it into bits, several times in a row, and

then letting a computer try to piece the blueprint back together.

Each pass is flawed, but collectively, they add up to a whole sequence.

Venter wasn't shy about letting the other HGP leaders know they were doing their job

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遺伝子の世紀：科学のクラッシュコースの歴史 #42 (The Century of the Gene: Crash Course History of Science #42)

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