Hi, you're listening to Cultivate
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educational facility in Fort Walton Beach,
Florida.
This podcast is perfect for anyone curious
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Hi, I'm Jacie, the social media coordinator
at the Emerald Coast Science Center.
Hi, I'm Harley and educator and the
community affairs coordinator.
And hi, I'm Diane, the director.
And today we're going to talk about
an episode that is very near and
dear to my heart.
Our episode today is going to be
on National DNA Day.
So National DNA Day is an annual
global celebration of the discovery of the
DNA double helix structure.
This year is an extra special year
because people across the world on April
25, 2023, will commemorate both the 20th
anniversary of the Human Genome Project's
completion and the 70th anniversary of the
discovery of the DNA double helix.
Published in The Nature Journal, the
Human.
Genome Project is one of the greatest
scientific feats in history.
The project was a voyage of biological
discovery led by an international group of
researchers looking to comprehensively
study all the DNA known as the
genome of a select set of organisms.
Launched in October 1990 and completed 20
years ago, in April 2003, the Human
Genome Project's signature accomplishment,
generating the first sequence of the human
genome, provided fundamental information
about the human blueprint, which has since
accelerated the study of human biology and
improved the practice of medicine.
So let's talk a little bit about
the discovery of the DNA shape.
70 years ago, two scientists had a
flash of insight that changed the world.
On February 28, 1953, james Watson and
Francis Crick discovered the structure of
DNA, the now famous double helix.
On April 25, 1953, the discovery of
the structure of DNA was published in
The Nature Journal.
Their discovery helped unlock the mystery
of our genetic code, and it helped
us understand what makes us us.
Roslyn Franklin produced a crucial X ray
photograph of DNA that was used by
Watson and Crick.
Franklin is widely acknowledged as playing
a major role in the discovery of
DNA's double helix structure and, in fact,
published a paper on her findings that
accompanied Watson and Crick's research.
So let's talk a little bit about
Roslyn Franklin.
Rosalind was a British chemist and X
ray crystallographer whose work was
central to the understanding of the
molecular structure of DNA RNA, viruses,
coal and graphite.
Although her works on coal and viruses
were appreciated in her lifetime,
franklin's contributions to the discovery
of the structure of DNA were largely
unrecognized during her life, for which
she has been referred to as the
wronged heroine.
A feminist icon and the Sylvia Plath
of molecular biology.
Franklin is best known for her work
on the X ray, diffraction images of
DNA while at King's College London.
Particularly photo 51 taken by her
student, Raymond Gosling, which led to the
discovery of the DNA devil helix, for
which Francis Crick, James Watson and
Maurice Wilkins shared the Nobel Prize in
Physiology or Medicine in 1962.
Okay, so before we move on, I
have to put in my little two
cent about Roslyn Franklin, only because
I'm a science history nerd and this
is the kind of stuff that I
just absolutely love to roll around in.
So we wouldn't have known much at
all about Roslyn Franklin's contributions
to DNA if it wasn't for a
book that James Watson wrote shortly after
winning the Nobel Prize.
And the book is called The Double
Helix.
And everybody that was mentioned in the
book was supposed to have an opportunity
to read the book before they went
to publish it.
Well, by this time, Roslyn Franklin had
already passed away.
So she died of cervical cancer, which
is another reason why she wasn't included
in that Nobel Prize.
Nobel Prizes are only given to three
individuals in any discipline and also
they are not handed out posthumously.
So because she had already passed away
when they went ahead to go and
give out the Nobel Prize in 1962,
that's why she wasn't included on it.
So in his book, he just rips
her to shreds.
And even James Crick and Maurice Wilkins
read the book and they were like,
this is not exactly the way things
played out.
And honestly, I think it's more like
maybe Watson knew that he couldn't have
done it without her work and so
he just decides to totally to go
for her and in order to make
it seem like, yeah, I'm the one
that did all of this, but he
couldn't, he absolutely could not.
They would not have had access to
the insights that they, quote, had it
not been for being able to see
photo 51, which Roslyn Franklin did not
show to him, but her lab partner,
or he's not her lab partner because
they had kind of an antagonistic
relationship.
But Maurice Wilkins had showed Watson and
Crick because Crick and Wilkins had been
friends for a number of years.
So Maurice Wilkins fed all of Roslyn
Franklin's data to Watson and Crick and
that's how they were able to come
up with the, quote, insight, that eureka
moment.
And also it was a lot of
other people's work.
So when they went to go publish
the article in the journal Nature to
talk about how they had discovered what
the structure was, they realized that
Franklin had never published her work and
her X ray crystallography work.
So then they couldn't explain how they
came up with what they did unless
her work was also published.
And they did.
Three papers were published in the same
issue of the journal Nature.
Watson and Cricks was published first,
then the second paper, and the last
paper to be published was Roslyn
Franklin's.
So that way it made her work
appear like she was confirming what Watson
and Crick said, as opposed to actually
her work being the foundation for what
Watson and Crick had done.
So she had been severely maligned.
And I'm happy to say that over
the course of the years, more about
her has come to like and I
think that she is finally getting the
recognition that she deserves for all of
the work that she did.
And when she went into this lab
at King's College, she was, like, 31
years old.
She was a female.
It was right after World War II.
She was Jewish, and she wasn't even
allowed to eat lunch in the lunchroom
because it was for men only.
So, I mean, she really fought a
lot of battles, and she was a
very driven individual and very, very
focused on her work, which kind of
put people off, because they didn't expect
that in a woman.
Exactly.
Anyway, so I just had to give
some love to Roslyn Franklin, fight for.
Her one more time.
Yeah, exactly.
Put it out there that she was
a rock star.
So now we're getting ready to talk
about another rock star in the field
of genetics and DNA, also another one
that had been completely overlooked until
somebody wrote a book about her.
But this is henrietta lax.
And there was an incredible book by
Rebecca Sclud called the immortal life of
henrietta lax.
And her contribution didn't really get the
recognition that it deserved until that
book came out.
So if you haven't read that book,
I highly recommend that you read the
book because it's an excellent, excellent
story.
So, in 1951, at 31 years old,
henrietta Lax died from an aggressive form
of cervical cancer only ten months after
seeking treatment at John Hopkins for what
she felt was a knot in her
womb.
During her treatment at the hospital,
samples of her cancerous tissues were
taken from her cervix, and these cells
went on to become the immortal cell
line known as the Helicells.
The HeLa cells are immortal as they
have an overactive version of the enzyme
telomerase that prevents the shortening of
the chromosome telomeres and so prevents
cellular aging and cell death.
HeLa cells can also proliferate abnormally
fast, even in comparison to other cancer
cells, and have the ability to contaminate
other cell lines.
So up until that point, they had
tried to grow human cells outside of
the body to use for testing, and
they hadn't had any luck at all
until they had come across these cells.
Now, Henrietta Lax was black, and at
the time, in the 1950s, john Hopkins
had a ward that was for people
that were black.
And so a lot of those patients
weren't paying patients.
And so they didn't have an issue
with taking these cells because they kind
of looked at it as a form
of paying for the work that they
were having done, because they weren't
paying patients now bioethics is
completely different.
A lot of that having come out
of the fact that they had taken
her cells.
In John Hopkins defense, they never
charged anyone else, they made no money
off of her cells and they sent
her cells out to everywhere in the
world.
They have been used like everywhere in
every type of major medical research that
there is.
Everybody uses the HeLa cells.
So much so that John Hopkins is
building a brand new building right now
and it is going to be named
after Henry Adelax.
They understand that things have changed
over the years and they didn't recognize
her contribution in the manner that they
should have and so now they are
trying to fix that because we are
still using the HeLa cells in all
of this research.
So a couple of areas that it
has made huge contributions to is in
polio eradication.
So Jonas Salk developed a polio vaccine
in the early 1950s but he was
struggling away to find to test N
field trials and he was using Rhesus
monkey cells at the time but they
were really expensive for a large scale
study.
And so in 1952 he was able
to use the HeLa cells and continue
his polio vaccine research on those as
well using the HeLa cells we have
also learned a lot more about how
to improve cell culture practices because
we did say that the HeLa cells
could also contaminate other cells.
So now we know that we need
to use certain procedures like what types
of containers to put them in, how
to have sterile rooms, how to handle
them so that they don't contaminate and
they don't get contaminated.
So this is again a lot of
general standard operating procedures in
cellular biology that we have learned
through the use of the Helocells and
some other things.
The idea of us having 23 chromosomes
came from the use of HeLa cells.
Previously, they believed that we had had
24 chromosomes.
But by using the HeLa cells to
research this, they determined that we
have 23 chromosomes.
And then genome mapping.
And that kind of goes into the
human genome project as well, but also
genome mapping in order to help us
to find what the genes are, where
they're located and who is responsible for
protein production and what areas are just
parts of junk DNA.
And then the last one that has
become a really big help has also
been the HPV vaccine, the human papilloma
virus vaccination.
And this is shots now that young
girls can get in order to help
them not develop this type.
It can develop into cervical cancer and
so this could help reduce the cervical
cancer rates by 70% by having the
HPV vaccination and this also came from
the HeLa cells.
So she has very, very far reaching
implications and it was kind of just
like a random thing.
I can remember if you read the
book or you listen to the story
about her.
It talks about the researchers when they
come in, like, the next day, and
these cells are proliferating and they're
growing like, whoa, hey, that's never
happened before.
Oh, my gosh, this is crazy.
So she is definitely one of those
people that has had a huge influence
on the lives of every single person
moving forward.
All right, what we're going to talk
about next is Jennifer Duna and Emmanuel
Sherpinier.
Jennifer Duna is an American biochemist
who has done pioneering work in CRISPR
gene editing that's CRISPR and made other
fundamental contributions to biochemistry
and genetics.
Emmanuel Charbenier is a French professor
and researcher in microbiology genetics
and biochemistry.
In 2022, they received the Nobel Prize
in chemistry for the development of a
method of genome editing through CRISPR.
This was the first science Nobel Prize
ever won by two women only.
CRISPR gene editing is a genetic
engineering technique in molecular biology
by which the genomes of living organisms
may be modified.
It is based on a simplified version
of the bacterial CRISPR CAS Nine antiviral
defense system.
By delivering the CAS Nine nuclease
complex with a synthetic guide RNA or
gRNA into a cell, the cell's genome
can be cut at a desired location,
allowing existing genes to be removed and
or new ones added in vivo.
It can be used in the creation
of new medicines, agricultural products,
and genetically modified organisms, or as
a means of controlling pathogens and
pests.
It also has possibilities in the treatment
of inherited genetic diseases as well as
diseases arising from somatic mutations
such as cancer.
In 2012, Duna and Sharpene were the
first to propose that CRISPR CAS Nine
enzymes from bacteria that control
microbiome immunity could be used for
programmable editing of genomes, which has
been called one of the most significant
discoveries in the history of biology.
Since then, Duna has been a leading
figure in what is referred to as
the CRISPR revolution for her fundamental
work in leadership in developing CRISPR
mediated genome editing.
And you guys remember we had two
female rats that were donated to us
at about the same time in 2020
when they announced the Nobel Prizes.
We named them Jen and Emma after
Jennifer Downett and Emmanuel Sharpignier.
Yeah, because that was I forgot such
a cool thing to have.
It was really woman only.
Yes, it was.
CRISPR also had a huge impact on
sickle cell patients.
Sickle cell anemia is a well known
disease affecting millions of people
worldwide and is the most common blood
disorder in the United States.
This is identified around 100 years ago,
and sickle cell anemia was the first
disease that was proven to have a
molecular cause and has been widely
researched.
Sickle cell anemia is a genetic blood
disorder that affects hemoglobin, the
oxygen transporting molecule in red blood
cells.
Sickle cell disease causes the body to
produce hemoglobin S, an abnormal form of
the molecule that distorts the shape of
the red blood cells and disrupts their
function.
These rigid, distorted cells obstruct
blood vessels and inhibit circulation,
causing severe pain and recurrent
infections.
Sickle cell anemia is caused by the
mutation of a single base in the
DNA sequence of the bGlobin gene HBB.
In healthy individuals, position six of
the resulting amino acid sequence is
glutamic acid gag.
However, in sickle cell anemia patients,
this is substituted for Avalene, then
resulting in GTG.
This mutation results in the formation of
hemoglobin S, the disease associated form
of the protein.
Treatment options for sickle cell anemia
are currently limited.
Patients typically require frequent blood
transfusions, and medications are
typically recommended to relieve the pain
attacks or reduce their frequency.
Some medications can promote fetal
hemoglobin HBF production to replace the
faulty adult hemoglobin, however, they
carry associated health risks.
Antibiotics are often prescribed to
patients in order to prevent frequent
bacterial infections, particularly in
children.
A transplantation of bone marrow from a
healthy donor is also an approach, but
it has significant challenges, including
identifying a suitable donor, immune,
rejection of the transplant, and graft
versus host disease, which is also known
as Gbhd.
So as sickle cell disease is caused
by a genetic mutation, it is a
perfect candidate for CRISPR mediated gene
therapy.
In 2020, there were CRISPR trials to
see if sickle cell disease and beta
thalassemia could be treated.
Using what is known as CTX One
therapy.
This trial extracted hematopoietic stem
cells from the bone marrow of two
patients, one with sickle cell disease and
one with beta thalassemia.
The BCL one one, a gene in
the cells, was the CRISPR edited in
order to restore HBF before cells were
reintroduced into the patients one year
after treatment.
The results of the trial have been
extremely promising.
Both patients displayed increased levels
of HBF with blood and bone marrow
cells, maintaining high levels of allelic
editing and no need for subsequent blood
transfusions.
While there appear to be some side
effects of the treatment, all have been
treatable.
Victoria Gray, the patient who had sickle
cell disease, says her life has been
transformed.
In March, she was in London to
describe her landmark experience at the
Third International Summit on Human Genome
editing.
The summit brought together more than 400
scientists, doctors, patients,
bioethicists, and others from around the
world to air the promise of gene
editing as well as host a lot
of questions that the technology is
raising.
I would just recommend.
There's a great book called The Gene
by Siddharthur Mukherjee, and he kind of
goes into the whole entire history of
DNA, starting with Darwin, to mendel, to
where we are now and written very,
very well in very layman terms.
So that's a great book if you
just want to learn a little bit
more about it.
Every book that he writes has been
fantastic.
His latest book is called The Cell.
So he treats the cell in basically
the same way, like the total history
of the cell and all the different
parts and pieces reside within a cell.
There is another good book about Jennifer
Daldna, and it's called The Code Breakers,
and it talks about her and Emmanuel
Sharpignier's work in discovering and
developing CRISPR techniques.
So that's another great book.
And then just this morning, when I
was riding the bike at the gym,
I rewatched the Nova episode of photo
51.
And that goes into a great detail
about the discovery of the DNA structure
and sort of like the worldwide battle
and race that was going on to
figure out who was going to be
the first person to elucidate the
structure of DNA.
So that's a great episode.
So I highly recommend that one as
well.
All right, that's all for this episode
today.
We will see you guys in two
weeks, and thank you for listening.
Thank you for listening.
Thank you.
Bye.
Thanks for listening to this week's
episode of Cultivate Curiosity.
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