- Good afternoon, everyone.
It's a wonderful pleasure to
be here on our home campus,
and I just feel like I've
got my extended family
here in the room.
I have to tell you that when
I moved to Berkeley in 2002,
I was recruited here from Yale University
by some of the distinguished
people in this room actually.
And I knew I was moving
to an exciting place.
I've been very happy at Yale,
but I knew this was
sort of opening the door
to a lot of new exciting
opportunities and research.
What I didn't think about at the time,
but I've come to appreciate,
especially in recent years and
you'll see in this lecture,
is that our great
university is much more than
any individual department.
So, I'm fortunate to work in
two great departments here,
but there's so many ways
that this university
has now contributed to my thinking
about the future of genome editing,
where it's going in a
societal sense, a legal sense,
and an ethical and moral sense
in addition to all of the opportunities
in clinical medicine,
agriculture, et cetera.
So, I feel like I am so
lucky to be at a place that
has been fostering my intellectual growth
in all of those different realms.
And I think this lectureship
in honor of Dr. Elberg
certainly is very
fitting in the sense that
he is someone who has inspired many of us,
reading about his life and
his work here at Berkeley
is just sort of, to me, epitomizes why
Berkeley is such a great
place to have the opportunity
to work and work with such great students.
So, that's my little trivia to Berkeley.
And what I wanna do today
is I'm gonna tell you
a story really about some research
that started here at Berkeley with
just a collaboration among colleagues,
and then an international partnership
with Emmanuelle Charpentier
that led in an unexpected direction.
And it produced some science that has
profound implications going
forward in different areas of,
of course in medicine and agriculture,
but also makes us really think about
what it means to be human
and what it means to have
the power to manipulate
the very code of life.
And I wanna get into some
of that today with you.
I'll talk for, hoping to
talk for about 40 minutes,
and then I wanna save a
generous amount of time
for discussion at the end.
So, to get into this,
I wanted to introduce
the topic of genome editing
by pointing out that
a lot of times in science,
and this something I love
about being a scientist,
we do experiments in the lab
because we have an idea about something.
We have something we wanna test,
and the result isn't something
you could've predicted.
It takes your work in
an unexpected direction.
And that was exactly the case
for the work that led to
the CRISPR-Cas9 method
for genome editing,
because this was a project that began as
a curiosity-driven
experiment to understand
how bacterial fight viral infection,
something that might sound rather esoteric
to folks in the room, and
yes it is, in many ways.
But it was something
that I was curious about.
And through that research
that we did in partnership
with various colleagues,
this led through an understanding
of this bacterial immune system
that allowed it to be adapted
as something very different,
namely a tool for
manipulating the DNA sequences
in any type of cell or organism.
And this really started with
a conversation that I had
with a colleague here at
Berkeley, Jillian Banfield.
And this is one of the
great things about Cal.
Jill called me one day, it was
probably around 2006 or so,
and she said, "Jennifer,
I don't really know you.
"We don't really know each
other, but you're doing
"the type of research that I
think could be very interesting
"for something that I've
stumbled across in my own work."
And she proceeded to explain to me that
she studied the DNA isolated
from different kinds of bacteria
and the viruses that infect
those bugs in the environment.
And she'd come across
something very mysterious,
that was intriguing,
and that was the fact that many bacteria
in their chromosomes,
and this is a diagram that illustrates
the circular chromosome of
a typical bacterial cell,
many bacteria have a sequence
of DNA in the chromosome
that is a storage site for sequences
of DNA sequences that come from viruses
that infect those cells.
And these DNA sequences
have a distinctive pattern
of repetitive elements that
flank unique bits of DNA
that are stored from viruses,
and they were called CRISPRs.
So when you see the acronym CRISPRs,
even if you don't know what
it actually stands for,
now you know that it really represents,
it's an acronym that is describing
this repetitive DNA element
that is a genetic
vaccination card for bacteria
where they store records
of past infection.
And what Jill wondered was
whether these sequences
might in fact be a signature
of a bacterial immune system,
a way bacteria could
prevent future infection
by those viruses.
And one clue to this was
that many of these organisms
in addition to having these
repetitive CRISPR sequences,
they also had CRISPR-associated
genes that encoded proteins
of unknown function at the time,
that were nonetheless always
inherited with CRISPR arrays.
So it had the look of some
kind of conserved system
that might have evolved over time
to do something very specific.
And what we now know,
and this is really based on
work that was done initially
by a scientist working
in the dairy industry,
we're studying the kinds of bacteria
that are used to culture
yogurt and make cheese,
is that in bugs that have a CRISPR system,
they in fact can adapt to viruses
and protect themselves
from future infection.
And here's how it works.
So this is a cartoon of a bacterial cell.
And if that lucky has a
CRISPR system in the genome,
then whet it gets infected by a virus
which injects its DNA into the cell
and starts to make all of the molecules
that are necessary to make viruses,
this cell can in fact acquire
a little sequence of DNA from the virus
and store it in the CRISPR
array in the genome.
And then the cell makes little
copy of that CRISPR array
in a form of a molecule called RNA.
It's a genetic cousin of DNA,
so it provides the zip code
for the system to recognize
viruses that might have
a matching DNA sequence.
And those RNA molecules
combine with proteins
encoded by the Cas genes to
form surveillance complexes
that utilize the RNA sequence,
the letters in the RNA,
to find matching sights in DNA molecules.
And when those matches are
found, then the Cas proteins
are able to cut up that
foreign DNA and get rid of it.
So it's a great way for bugs
to adapt to viral infection.
And the amazing thing about
these pathways is that
Jill Banfield's work
and others who are working in this field,
very small field at the time,
were in fact uncovering
many different examples
of these CRISPR pathways.
It's not one immune
system, but in fact many.
And I wanted to show
you this great picture
from Jill's lab.
These are two members of Jill's lab,
including Christine He,
who is a joint post doc between our labs.
And what these lucky lab
members get to do in their work
is go out on field trips like this
and they collect samples of ground water,
samples of soil, and they are
able to filter those samples,
and isolate the bacteria
that might be growing
in those environments,
and then the DNA from
those bugs is sequenced
and used to look for new
examples of CRISPR systems,
as well as lots of other
kinds of interesting pathways
that these bugs might be using.
So it's a field that's
known as metagenomics.
And it's really interesting
because we often don't even know
what these bugs are.
They've never been
identified by scientists
or cultured in a laboratory.
And nonetheless, by doing this
kind of metagenomic research,
you can get a lot of information
about the lifestyles of these organisms.
And so, this kind of work has uncovered
many different flavors of
CRISPR-Cas immune systems,
and I'm showing you here at
slide that just illustrates
in cartoon fashion the collection
of different kinds of
CRISPR-Cas enzymes and proteins
that are a part of these pathways.
And I just want you to notice that
overall we can divide these
systems into two categories
known as Class 1 and Class 2.
And the thing that
really distinguishes them
is the fact that the Class 1
systems consist and require
multiple proteins that provide
protection from viruses,
whereas the Class 2 systems
each consist of a single
large gene that encodes a big protein
that's responsible for protecting cell.
So, rather than requiring
a whole set of protein,
one protein does everything
to protect the cell.
And so, it was really that
sort of thinking about this
difference in these types
of CRISPR systems in nature
that led to a partnership
that I established
with Emmanuelle Charpentier's
lab back in 2011
to investigate the function
of a particular gene,
a gene encoding a protein known as Cas9.
And we were both at a conference together.
We're scientists who came from
different parts of the world,
and our science had,
you know, we were coming
from very, very different
scientific backgrounds.
But when we met a conference, we realized
that we were both interested
in the same question.
What is the function of this Cas9 protein?
It seemed a like a fascinating,
must be a really interesting protein
if it could provide this kind
of programmable protection
against viruses.
And that embarked my
lab and Emmanuelle's lab
on a wonderful collaboration
to answer this question.
Two scientists working
with us, Martin Jinek,
a post doc here at Berkeley
in my lab at the time,
and Krzysztof Chylinski
in Emmanuelle's lab
working in Vienna at the time,
figured out that Cas9 is an amazing enzyme
that has the ability to
recognize segments of DNA
at sites that match a 20-letter
sequence in the guide RNA.
And remember that this
would be a RNA molecule
coming from and derived from integrated
pieces of DNA in the CRISPR locus
that record a past viral infection.
So, by definition, these
RNAs are able to recognize
matching DNAs that come
from those viruses.
And so, in this cartoon right
here, I hope you can see that,
you can see the laser pointer.
This piece of RNA provides the
address for DNA recognition.
And when the protein,
which is shown in blue,
recognizes that segment of DNA,
it's able to unwind the DNA duplex,
and then two chemical
centers in the protein
generate a double-stranded
break in the DNA.
And that's really how it works.
So, in bacteria, when
that break is generated,
the bacterial cell is able
to quickly then degrade
those ends of the DNA.
And if that's a piece of viral DNA,
then the virus goes away.
And importantly, by doing
these biochemical experiments
where we had purified the Cas9 protein
and we're figuring out what
were the essential components
for this RNA-guided DNA
recognition and cutting,
Martin and Krzysztof figured out
that the system requires
a second kind of RNA,
this little molecule here
shown in red, called the tracr,
which creates a structure
for binding to Cas9.
So, in the laboratory, it was
essential have both of these
types of RNA molecules present with Cas9
for targeted recognition
and cutting DNA to work,
and we quickly show that
that's true also in cells.
Now Martin Jinek, being
a terrific biochemist,
was very interested in kind of the minimal
components of the system,
and he was busily kind of figuring out
what the essential parts of
these RNA molecules might be
and he realized that you
could actually link together
the part of the RNA that
provides the address label
with the part of the RNA
that provides the handle
for Cas9 assembly.
And this created what we call
the single guide form of the RNA
that in a single molecule could provide
both the ability to bind to DNA
and the ability to recruit
this Cas9 protein for cleavage.
And when we did this experiment
and saw that this single-guide RNAs
could easily be altered on this end
to recognize different
places in a DNA sequence,
whether that DNA molecule
was a very short molecule
tested in the test tube
or whether it was an entire
chromosome of a cell,
we realized that our work that had started
as a curiosity-driven project
to understand the bacterial immune system
had the potential to go in a very exciting
and very new direction.
And that's because by introducing
a targeted break to DNA,
it could be possible to
trigger genetic changes
to be made to the DNA in the process
of repairing that break.
And that's because in many
other labs around the world,
really over the past several decades,
people had been studying
the process of DNA repair,
especially in human cells
where misrepair of DNA
can lead to cancer and other problems,
and so there's lots of interest
and understand how this works.
And it was appreciated that in our cells
and in plant cells and other
kinds of animals and plants,
when double-stranded
breaks occurred to the DNA,
rather than leading to rapid degradation
like happens in bacteria,
instead, the cells can
recognize that break and fix it.
And they repair it by either introducing
a very small disruption to the DNA
and the process of pasting
those ends back together
or by integrating a new
segment of genetic information
if a template DNA molecule
is available in the cell,
something that is easy for scientists
to introduce in a research setting.
And so by doing this, you could actually,
if you had a way to introduce
a targeted break to a genome,
you could actually carry out
something that at the time
was called genome engineering.
You could literally
change the DNA sequence
at a particular place by inducing the cell
to make that change in the
process of repairing DNA.
And I wanted to show you a
video that was created by
a wonderful colleague and scientist
at University of Utah for us, Janet Iwasa,
that shows how this works when we
put these molecules into human cell.
So when we go into the cell,
of course the DNA in a human
cell is inside the nucleus.
It's packaged as chromatin,
so it's wound around histone proteins.
And amazingly, the Cas9
enzyme can use its guide RNA
to find a matching sequence
of DNA in the genome.
And when that match occurs,
the protein is able to unwind the DNA.
It forms a hybrid with the RNA,
little helix inside the protein.
And then the DNA is cleaved,
and the broken end is handed off
to other enzymes in the cell
that can repair the break by
in this example, inserting a new segment
of genetic information.
So it's a very powerful tool.
And amazingly, after we publish this work
in the summer of 2012, very quickly,
labs around the world
started to adopt this method
for genome engineering.
And quickly, that word
turned into genome editing,
because we all realize
that with this technology,
it became much easier now to change
the sequence of DNA
precisely and accurately.
And it really became a democratizing tool
that allowed labs to do experiments
that in the past would've been prohibitive
for various reasons, whether
due to expense or time,
or just technical difficulty.
Now, suddenly those kinds
of experiments became
a lot easier.
And so, just to, for those
of you in the room that
if you're not reading the
scientific literature every day,
just to give a sense of what's happened
over the past few years,
this technology just took
off incredibly quickly.
And I wanted to just
show you an illustration,
this is actually from the
Elsevier Journal website,
just showing the numbers of publications
over the last few years
with different technologies
for genome editing.
And so, before there was CRISPR,
there were tools for altering genomes
that were based on having
to engineer proteins
that could cut DNA precisely,
and these are shown in
these three examples here,
and these were adopted initially.
But once the CRISPR
technology became available,
it really took over.
And the reason is that it's
just a lot simpler and faster
to be able to change a molecule
that provides the address label
for a single protein, Cas9,
is the same in everybody's experiment,
whether they're working with human cells,
or wheat cells, or zebra
fish, or anything else.
They just have to change
the address label,
this RNA molecule, something that is
relatively trivial to do with
molecular biology methods.
And so, for me, as a biochemist
and a structural biologist,
this experience of doing this work
and then sort of being part of this
revolution really that's happening
where we have a new technology
that's incredibly enabling
has been very exciting and
also incredibly challenging.
And I wanted to share
with you just a few things
that we've been working on in the lab
and just very briefly tell you
some of the questions
that we're still asking
in the laboratory and trying
to understand the answers to,
and then I really wanna dive
in to where this is all going
in terms of what's going to happen.
How is this going to affect
of our lives in the future,
and what do we do about it?
How do we think about it?
And so, to start with a little bit
of the science that we're doing.
So, we've always been fascinated
with how molecules work.
And I still find that every
morning when I wake up,
that's usually the first thing on my mind,
is I'm thinking about experiments
that I've been discussing
with the members of my lab
and our collaborators and our colleagues,
and wondering what are the
results of those experiments.
And one of the things that
we've bene puzzling over
is really understanding the mechanism
by which this Cas9 enzyme
is able to function
as an RNA-guided protein.
So, think about it, this is
an incredible molecule, right?
Because it's a protein that
has this little address label.
And somehow, by mechanism
that is still being dissected,
it's able to interact
with the DNA in a cell
so precisely that it find a
20-letter sequence in the DNA
out of all the billions
of base pairs in a DNA,
three billion for example
in the human genome,
and it finds that 20-letter stretch.
And most of the time, it
does it pretty accurately,
and it makes a cut in the DNA.
and so how does that work?
And so we've been studying this
using a variety of techniques,
including X-ray crystallography,
electron microscopy.
Those are techniques that show us
the structure of molecules and
what they actually look like,
as well as all sorts of ways of
probing the behavior of these molecules,
whether it's in the test tube in the lab
or whether it's actually in living cells.
And that work has showed that
this is actually a 3D
printed model of Cas9.
It's based on a
crystallographic structure,
and it was actually solved by my
former post doc Martin Jinek,
who is now a professor at
the university of Zurich.
And what this shows is the white protein,
which is the white part
of the model here, Cas9,
with its guide RNA, the orange molecule,
that's the address label,
holding onto a DNA molecule
that is unwound inside the protein,
so that it can make this
precise set of base pairs
with the RNA.
So there's a transient RNA-DNA helix
that forms inside Cas9.
When that occurs, the
proteins has a sensor
that now triggers cutting of the DNA.
We understand now a lot about
how that works by a lot of,
and I could have several
hours to tell you all of this,
but this is really all of the
work that's been over the
last six years in our lab
by a whole collection of
undergraduates, graduate students,
post docs and technicians
who've been able to
sort of tease apart how
this actually works.
And I want to show you another.
This is just a representation
of a structure of a related
enzyme called Cas12.
It's also an RNA-guided
DNA-cleaving protein
that's a member of the
related CRISPR-Cas system.
And this just shows you how this,
again, this protein is structured
so that it holds onto the
orange molecule, the guide RNA.
And as the DNA traverses the protein,
it unwinds inside the enzyme
to allow access to each strand
of that DNA double helix,
so that cutting can occur.
Now these proteins amazingly
are able to open up
the DNA duplex, but they do it
without any external energy source.
They somehow coax apart those DNA strands,
and that's a fundamental question
that we're still puzzling over.
How does that work?
Because it's critical for the mechanism
of these enzymes that they
are able to gain access
to the DNA helix, and not only that,
unwind the duplex so that it can be cut.
And one of the things that's
emerged from our research
over the last few years is
that these types of proteins,
and I'll show you this example for Cas9,
our enzymes, they're able
to change their shape.
They're sort of like shape shifters.
And this is an example that shows
a comparison of different crystallographic
structures that we have of Cas9.
And the animation starts
with the protein alone,
morphing to this shape that it forms
when it binds to the guiding RNA.
Once that occurs, there's
a channel in the protein
that is available for binding to DNA.
So that's a really big rearrangement
of the protein structure.
And once DNA binds in
this central channel,
there's an additional
rearrangement of the protein
to accommodate that RNA-DNA helix.
And then finally, this part
of the enzyme right here,
this yellow piece, swings into position
so that it can actually cut the DNA.
This was initially a model
for how Cas9 might work
as sort of a construct in our minds
for how it might work,
but we've been able to
test all of these steps
using different chemicals methods.
And we now feel very confident
that this model is correct,
that this is really an
enzyme that's designed
to grab on to DNA, disrupt
the helix probably in part
by changing the shape of the enzyme
that pries apart those DNA strands,
and then only when it's engaged
with a correct matching sequence
that matches the guiding RNA
does the cleaver position
itself to actually make a cut
on the DNA.
So it's really an amazing little molecule.
So, I wanted to talk now about
what this kind of tool is enabling.
And I'm gonna focus on
three different aspects
of applications of genome editing.
I wanna talk a little bit about
applications in public health,
application in agriculture,
and then, finally,
applications in biomedicine.
Because one of the amazing
things about genome editing,
if you think about it,
every living thing that
we know on our planet
has a nucleic acid that encodes
the genetic information.
And for cells, that's DNA.
So given a tool like this,
it turns to that this is a technology
that is enabling in many
different areas of biology.
And so people of course have been
thinking about how you might use a tool
that allows changes to be made to DNA
precisely ad accurately.
How do you use that in ways
that are going to solve
real world problems?
And what's so interesting is that
it's allowed incredibly
creative an interesting things
to be either done or to
get into the pipeline,
but also raises, I think,
some very profound changes
in terms of the societal
implications of this work,
and ethical,
you know, the sort of ethical
issues that are coming up,
as well as issues of equity
and how we think about
a technology that's moving
so quickly in the laboratory.
And you saw with that chart
I showed you of publications.
I think the last time I typed
CRISPR-Cas9 into PubMed,
which is our search, sort
of the library of medicine,
I came up with close
to 10,000 publications
just in the last two years.
So, it just gives you a
sense of how exponential
the growth has been in
the use of this tool,
but that's moving so
much faster I would say
than any of the grappling
with these kinds of
challenges that we're doing.
And so this is why it's so important
to have people thinking about this
and get it engaging and
what it means to have
a way to literally
control the code of life
and to control the evolution
of organisms, including ourselves.
So, in public health, so one
of the things that's happened
is that people have
appreciated that you could use
the CRISPR-Cas system in ways
that will have a clinical impact
but not necessary involve using
genome editing directly in people.
And this is an example here where
scientists are using gene editing
to later the DNA of animals like pigs
that are envisioned to be
good organ donors for humans
and using it in two ways.
One is to remove endogenous
viruses from the pig DNA
that could otherwise
potentially infect humans
that received organs
donated by these animals.
And the other is to make
the organs in these animals
more human-like,
so they're less likely to
induce an immune reaction.
And that's actually work that's going on
both in academic labs and
also in companies now.
So that scenario where,
this is something that
I mean a few years ago
I wouldn't have every imagined,
something we were involved in
having that kind of effect.
And yet this work is moving
forward really quite quickly.
And I think that most people would agree
that this is an exciting
potential application of this
that could solve a real problem,
which is the scarcity of organs
that are necessary for donations.
And then another area of
interest in public health
si an area where I would say
there are both very
interesting opportunities
but also some real ethical challenges,
and that's in an area
that we call gene drives.
Maybe some of you have
seen this in the media.
In fact, there was just a
story recently on MPR about
gene drives in mosquitoes.
And I just wanted to very briefly
explain what a gene drive is.
And it's basically a way of
introducing a generic trait
very quickly through a
population of organisms,
and it requires an efficient way
of integrating genetic
information into the genomes
of these organisms.
And this is a diagram that is adapted from
an article, recent
articles in Science News,
that just show show this
works in an insect population.
So, normal inheritance works like this
where we have traits that
are in each of the parents
and they have progeny,
and those traits are inherited
generally in a sort of
what's called Mendelian fashion.
that a trait in his animal
doesn't take over the population.
It's simply inherited
according to this lineage.
But if we have a gene drive in place,
and this is something that can be enabled
with a gene-editing
technology like CRISPR-Cas9,
now we have a way that if this animal
has not only a particular genetic trait,
but that trait is coupled
to the gene editor,
then every time it gets into an animal,
it will tend to get into
animals that don't have
that genetic trait.
As we follow this through this population,
and you can see that very quickly,
virtually all of the organisms have
this particular genetic trait.
We're no longer relying
on Mendelian inheritance.
Why would this be useful?
Well, people envisioned that you could
use such a technology
to control the spread of
mosquito-borne diseases by
creating animals in the wild
that are either unable
to spread the disease
or are steril for example,
which might lead eventually to
extinction of the population
if you took it to that extent.
And so there's I think
both incredible excitement
about the potential for this,
but also a growing recognition
that this could have profound
impacts in the environment
that need to be evaluated,
and we need to be very careful about
taking steps that might
be difficult to reverse
once they get unleashed.
So that's one of the
kinds of challenges that
a technology like gene editing
is now bringing to the fore.
I wanted to also speak about agriculture.
So, in agriculture, I personally think
that this is probably the area where
gene editing will have
the widest global impacts
in the near term because
everybody has to eat,
and there's lots of research being done
to alter plant properties that will
allow plants to resist
drought, to resist disease
potentially to be more nutritious,
and to do that using gene editing
so that genes can be
very precisely altered
without requiring years of reading,
as well as all of the genetic variations
that typically go along with traditional
breeding approaching for plants.
This is an example from a research lab
at Cold Spring Harbor
Laboratory, Zach Lippman,
who published a paper
showing that you could use
the CRISPR-Cas9 system
essentially as a rheostat
to dial up or down the numbers of fruits
that are produced by
plants such as tomatoes.
And he's done a lot of work on this,
showing that he's really
impacting the genome
at a place that is highly conserved
across different kinds of plants.
So you could start imagine
being able to control
crop production in many
different kinds of crops
using this sort of strategy
which sounds very exciting.
And there's work that was
done at Penn State University
by another academic research group
that was able to use CRISPR-Cas9
to knock out one gene,
a single gene, made a one-gene disruption
that creates a trait in these mushrooms
that prevents them from turning brown
when you cut them open.
And so, this was sort of a novelty
when they initially did this.
But again, the idea is that it demonstrate
how straightforward it now is,
at least in some settings, agriculturally,
to make these kinds of
targeted changes to plants.
And the big question
is, or a big question,
is how we all feel about that.
How do we feel about going
to our local farmer's market
or grocery store and picking
some mushrooms that have been
edited this way?
Are people going to accept
that or resist that?
And I've discovered that
depending on the country
that you live in, the answer
is gonna be different,
at least from an environmental,
governmental perspective.
Because in the United States,
the US Department of
Agriculture has decided that
any kind of gene editing that
leads to genetic knock out,
not introducing new genetic information,
is not to be regulated,
and it's not considered as
genetically modified organism
because it doesn't
contain any foreign DNA.
But if we go over to
Europe, it's very different.
In Europe, the ruling has come
down in the last few months
that organisms such as the mushroom
would be considered a
genetically modified organism.
Those would be regulated very strictly
or perhaps not even allowed
on the market there.
So, we're at this very interesting moment
where countries are having
to grapple with this,
and it will affect global markets for
products that are produced from,
everything from home farmers to
big commercial farming operations.
And then finally, I just wanna turn to
biomedical applications,
and this is actually a slide
from some of our own work.
So, one of the amazing
things about gene editing
is that even labs like mine
that are very firmly in the cap of
working on purified molecules
and thinking about mechanisms
have been enabled to do things
that we could've never
imagined doing in the past.
This is actually an
experiment done by a recently
graduated or departed
post doc, Brett Staahl,
who was able to show that he could make
modified forms of CRISPR-Cas9,
this little molecule diagrammed here,
and inject them into the brains of mice
that had been tagged with
a gene that turns red
when the DNA is edited precisely.
So that's a very nice marker
that tells us when and where
cells in the brain have
received a DNA edit.
You can see here that in this experiment
when these Cas9 molecules were injected
in two places in the mouse brain,
we got a fairly large volume of cells
that received a precise DNA edit.
And we're excited about this
because we're actually now
working with people at UCSF
to ask whether we can use this strategy
to treat neurodegenerative disease
and also to deliver molecules into tumors
that could be beneficial
for cancer patients,
something that a few years
ago I wouldn't have imagined
that I would be involved
in exciting work like that.
And then there's also
potential to do things
that are outside of directly delivering
gene editing into patients
that involve detection
of disease-causing DNA,
and this is using CRISPR-Cas
molecules as a diagnostic,
something that several students in my lab
pioneered really with their careful work,
understanding the real, some
of the sort of side functions
of these Cas proteins really,
and then recognizing that those activities
could be harnessed as diagnostics.
So those kinds of applications sound
like things that I think
all of us would agree
are worth moving forward
and don't really have
ethical challenges beyond
sort of the normal lens
we might think about for
developing therapeutics.
But what about editing the human germline?
This is an idea that really
came up very, very early
in the whole field of gene editing,
because people recognize that
if you could make changes
to what's called the germline,
that means in embryos or eggs or sperm,
you could actually
introduce genetic changes
that would become part
of an entire organism.
And not only that, they become heritable.
So they can be passed on
to figure generations.
And this was actually, this picture
was on the cover of The
Economist a few years ago
under the banner, Editing Humanity.
And they had a whole sort of article
imagining what would happen
if you could actually do this.
And so, just to explain this
a little bit more clearly,
I just wanna point out
for those of you that are not scientists
that we can really define
fundamentally two kinds
of genome editing.
One is called somatic cell editing,
and that means making changes to
say the brains of patients
or any other cells or tissues
in a particular organisms that
are not part of the germline,
they don't get transmitted
to future generations.
Versus what's called germline editing
which involves making heritable changes.
And once those changes are introduced,
it could be very difficult
to unchange them.
And so, those really become
then part of the whole lineage
of that organisms and all
of its future progeny.
And just to show you
sort of how this works.
So the idea is that you
could take a fertilized egg,
and this is actually
an example from our own
Russell Vance who's works here
at Berkeley in immunology.
So, he was one of the
early labs to adopt this
for germline editing in mice.
And this is an experiment in
his lab where they took a,
you see a pipette tip
coming in from the left.
It's holding onto a fertilized mouse egg,
still at the single-cell stage.
And you see a needle
coming in from the right
that's injecting the
gene-editing molecules.
And they go into the
cell, they edit the DNA,
and then as the cell
divides and makes more cells
and it forms an embryo,
then all of those cells
inherit that change to the DNA.
And so, back in 2015 really,
I guess it was even earlier than that.
So, 2014, I started talking
with a number of my colleagues
here at Berkeley about this,
and I found myself lying awake many nights
thinking about the potential
for this technology
that I've been involved in developing
being utilized in this fashion.
And I started to feel very
uncomfortable about it,
because it seem to raise a
lot of fundamental questions
about not only who we are as human beings,
but also things like eugenics
and societal inequities,
something we're talking a lot about now,
and who decides who would have the access
or ability to use that
kind of genome editing,
and is it right to use it all?
And so, with some
encouragement from colleagues,
we started through the Innovative
Genomics Institute here.
We held a small meeting
up in the Napa Valley
in January of 2015 to
discuss this question.
And that led to a much larger meeting
sponsored by the national
academies of science in the US,
the UK, and China to discuss this,
and ultimately resulted into
a report that was released
now almost about two
years ago, shown here,
about human genome editing,
and in particular human germline editing,
what did it mean, who
should be able to use this,
and what were the criteria for proceeding
if some scientist wanted
to use this type of,
had this idea for using this
application in human embryos.
Even then, it all seemed kind of...
It sort of seemed a little
bit science fictiony to me.
And I knew the potential is real,
but I sort of maybe was a
bit under the illusion that
scientists around the world
would respect the guidelines
that were put forward by this report.
But then,
around the end of November of last year,
I received an email,
it was I think the day after Thanksgiving,
with the subject line, Babies Born.
And the email was from this fellow,
He Jiankui, who is a scientist in China,
who I had encountered on a few occasions.
I didn't know him well.
In fact, he visited
Berkeley a couple of times.
And he told me through his email
that he had been involved
in a clinical study
where they used CRISPR-Cas9
to make changes to the genome of babies
who had actually been born.
As circumstance would have it,
we were actually all
on our way to Hong Kong
for the second international meeting
on human germline editing.
It was apparent to me
that his intension was
to announce his work at this conference,
and that's exactly what happened.
And I'm sure all of you,
unless you've been asleep
for the past few months,
have probably seen articles about this,
because it's been written
about quite a lot.
And it's really brought to
the fore this question of
using CRISPR-Cas9 or any
other gene editing technology
to alter the DNA of humans
in a heritable fashion.
And I just wanted to,
just so that you are aware
of what was actually done,
I mean we will discuss it a little bit.
I wanted to show you this picture,
which was actually from the Twitter feed
of a colleague of ours, Sean Ryder,
at the University of Massachusetts
who did a really nice service
to the scientific community
of going in and analyzing very carefully
the actual claimed DNA
edits that He Jiankui
reported completing in these
twin girls that were born.
And what Sean Ryder showed is that
although the stated purpose
of this application of
germline editing in these girls
was to remove a gene called
CCR5 or disruptors gene
that's responsible for,
that allows HIV virus to infect cells.
So, his stated purpose was to
give these girls protection
against future HIV infection,
something that sounds reasonable.
It turns out that the actual
edits that were introduced
into these girls are changes to the DNA
that have actually never
been seen in humans
at a detailed level.
These exact edits have never...
These changes have never
been observed in humans.
And in fact, they've never
been tested in animals.
And so, at the top is the
unmodified sequence of the gene.
This shows a naturally occurring deletion
called delta 32 that's been
observed in a few people,
and was the tip off that this was a gene
encoding a receptor protein for HIV,
but down here are the
actual genetic changes
that were created by He
Jiankui in these twin girls.
And what you can see is that these
do not look like this, right?
And so even if you don't
look at the details there,
you can see that they're different.
And so that means that what he did
was to actually make changes to the DNA,
and then implant those resulting embryos
so that they resulted in
pregnancies and live births
such that the resulting
people, these young girls,
have changes to their DNA
that have never been tested.
It's really a profound
thing to think about.
And I can tell you that when
I was sitting in the audience
at that meeting in Hong
Kong, I literally had...
the hairs on my neck were standing up,
because it seems so horrifying,
really, what had been done.
And I think that we're at a point now
where we have to think
about how to move forward,
and I wanted to put this up
to point out that the
World Health Organization
recently announced that they have convened
an international form of scientists
to really think hard about
where we go from here,
given that human germline
editing is now a reality.
And frankly, it appears not
that difficult to have done,
because this He Jiankui
is not an MD, for example,
and he was able to find various partners
to help him do his work.
We clearly as a scientific community
need to be thinking about
what's the next step here,
and this forum is charged
with putting in place
some more detailed
requirements I would say,
perhaps even regulations
that would be necessary
if anyone in the future wants
to proceeded down this path.
And the national academies in the US are
doing the same thing.
They're also in the
process of putting together
an international forum to look at this.
There've also been calls for moratoria
on this kind of application,
and maybe we'll have a discussion
about this a little bit,
and I have views on this.
And I'm just gonna close by
pointing out three things.
First of all, we're now in an era where
we have powerful editing tools
for changing DNA sequences
precisely and accurately
that are both advancing
science at a pace that is
really, really incredibly exciting,
but also raises these profound questions
that we really must grapple
with as we move forward.
Secondly, as I just said,
to really advance genome
editing to the next level,
we're gonna have to understand better,
I think, how it works and how
to control its activities.
When I say control, I
mean both in a chemical
but also in a societal sense.
And then we have to really think hard
about what kinds of
regulations should be in place
that will support science
and allow the science to advance
as quickly as possible
to solve real problems,
but will also, at the
same time, limit risk.
And I'm gonna just stop there,
thank people that I've had
the pleasure to work with.
This is my almost current group.
Some of these folks have
already left the lab.
This was taken a few months ago,
but wonderful students at every level
that have been working
with me over the years,
great colleagues here at Berkeley,
both scientific colleagues,
and also Emmanuelle Charpentier of course,
but also colleagues who are
helping us to think hard
about these ethical changes.
And then finally, any
scientific laboratories
dependent on funding to do our work.
And we are extremely grateful
for all of these organizations
for supporting our work.
Thanks a lot.
(audience applauding)
- So, it's a pleasure.
First, thank you for that
extraordinary talk and (faintly speaking).
We have microphones that will
circulate in the audience,
so please raise your hand if
you'd like to ask a question
and wait until the microphone gets to you.
This gentleman right back here.
- [Audience Member] So
you talked a lot about
regulations that need to be done
for the CRISPR-Cas9 system.
There are obviously,
there have been two sides.
One has been to sort of,
just some people would like
to say just completely outlaw
CRISPR technology and research
which you know would be pretty detrimental
to the potential the technology has,
or would also be probably being effective.
And then there's the other side who
wants to completely let lose
with the technology
and the research which,
again, would raise a
lot of ethical dilemmas.
So, what do you think is
the sort of sweet spot
in regulation-wise for
a way to respectfully approach
this technology ethically
and morally?
- Yeah, that's the so-called
$65,000 question, right?
(laughs)
You put your finger on it,
I think that's the challenge.
My personal view is that
it's probably not enough
to just say, as some people like...
There's an article by
Steven Pinker, for example,
at one point in the Boston Globe that said
bioethicis should get out of the way
and scientist should
do whatever they want.
I think that's going too far,
but I think that we need
to be thoughtful about
putting place appropriate guidelines
and frankly I would say regulations that
really establish a set of principles
where there's some price to be
paid if you cross that line.
And the changes is always how to do that.
And of course science is global now.
It's very hard to imagine
quite how we would regulate
or maybe enforce regulations globally,
but the good news is that
there are a lot of smart
dedicated people that are starting to
really grapple with that challenge,
including our own senator,
Dianne Feinstein, who is looking into this
and contacted as at the IGI recently
about legislation that she's,
or at least a statement
that she's considering
putting forward for
consideration and the senate.
So, I think we have to
be just very thoughtful
and thinking about how we put in place
a set of very clear requirements
that might turn into
regulations ultimately.
- Yes in the back.
Please wait for the microphone.
- [Audience Member] There
were news articles that said
that scientists are trying to bring back
extinct animals such as the woolly mammoth
using the CRISPR technology.
So I had a couple of questions.
So what stage is that research at?
And secondly, if that succeeds,
then what would the pros
and cons of that be?
- Well, yeah, so the
De-extinction Movement
is I think what you're referring to.
And it sounds exciting.
I think it's probably more in the realm
of science fiction
right now in my opinion.
Some of my colleagues like George Church
who's doing this work might disagree,
but I think the likelihood of being able
to actually bring back woolly mammoths
is gonna be challenging and
I'm not sure what the habitat would be
for those animals, too.
It's a bit hard to imagine quite
where we're gonna put them.
But you raise a great question.
I've talked to other colleagues who have
maybe less grandiose plans
for the de-extinction
but nonetheless want to explore this.
So, there are people
that are thinking about
could you bring back the
carrier pigeon, for example, or
could you engineer
birds to have properties
or were extent in animals
that have now gone extinct.
And so I think it's, again,
the way I think about it is
what a wonderful tool for doing research
and trying to understand
the evolutionary relationships
between organisms,
but I don't think we're on
the verge of Jurassic Park.
- Yes, here, please.
Please while you're waiting
to get the microphone,
please keep your hand up.
It'll be a little easier to
get the microphone to you.
- [Alex] Thank you.
My name is Alex.
Thank you for a really interesting talk.
So I think there's definitely
some cultural differences
between different countries
that are going to make
regulation very challenging just because
regulations in one country might not match
regulations in another country,
whether they're producing
them currently or not.
And so, as an outcome,
I think it's feasible
that there's a scenario where
this technology is going to be used
to add a germline stem cells
very quickly and for a while
somewhere where we might
not be able to control.
And so, you being so
involved in this technology,
how do you think our government
and our scientific culture
is dealing with the
potential outcome of that.
There are precautions of,
assuming that it will happen
and that it's already happening,
what are some of the steps
that our government is
taking that you might know of
that would actually deal
with this in some way?
- Well, I'll just mention three things.
I think hopefully everyone
heard that question.
It's just about how do
you think about regulation
in a global, in a global
sort of culture of science.
And given that individual
countries are gonna be approaching
this potentially quite differently,
I think for me it comes down to
starting with the community of scientist.
I think that engaging that
community to think together as...
That's why I think having
these international forums
is so valuable to put in
place what are seen as
essential requirements for any use of,
for example, human germline
editing by folks in the future,
and then using that as a basis for both
government regulations,
but also frankly for the behavior of
journal editors, let's say,
people who are involved
in making decisions
about what kinds of
science gets published.
And there's a lot of discussion about
should, like in this case of He Jiankui,
he wrote a couple of scientific
articles about his work
that have not yet appeared in
the peer-reviewed literature.
Should they be published or
should they not be published?
There's debate on both sides.
But I think that...
I think the scholarly
journals will play a big role
in disseminating information
and also deciding what kind of work
is worthy of being published
in those sorts of forums.
And then I guess the third piece is really
doing a lot more engagement
of people that are outside
of the scientific community.
It's a big challenge because people are...
I think, you know, everybody is busy,
and CRISPR sounds maybe scary
and maybe it sounds complicated and so,
but I think it's really key that we
have ways of communicating.
I've been experimenting at the IGI,
at the Innovative Genomics Institute.
We now have an artist
and residence program.
We have artists that have just arrived
that are gonna be helping
to work with scientists
to illustrate their work
and explain it in a more
maybe accessible fashion.
And we do a lot of
interaction with screenwriters
and science fiction writers
and people like that
who are probably gonna be doing much more
to disseminate information than any of us
individual scientist will be able to do.
So I think working outside of
our traditional comfort zones
is also gonna be key.
- Thank you.
Yes, here, please.
- [Audience Member] I'm not a member
of the scientific community.
I'm a political scientist,
so I'm interested in public policy
and you talked about balancing regulation
and limiting risk.
That's pretty straightforward.
He's working on that?
The concept of unintended consequences.
Let's take those two little girls
with the intent of
eliminating HIV vulnerability.
What's going on with grappling
with unintended consequences of this work?
- Yeah. It's a great question.
The unintended consequences
are potentially profound.
Unfortunately right now,
I only have more questions
than answers about that.
I think all of us at the meeting
in Hong Kong and since then
have been wondering what's being done
to follow up on the health of those girls,
to monitor their progression
as they start to grow up.
How do we try to understand, as you said,
with the unintended consequences of the
genetic changes that they received
and how those genes that were potentially,
apparently disrupted might be affecting
other aspects of their health
beyond susceptibility to HIV infection?
And then more broadly, how do
we think about going forward?
I can tell you that
there's tremendous interest
in human germline editing.
You might be surprised
or maybe wouldn't be,
but I'm contacted almost
daily by people that have
questions about it, even
people that want to do it,
and are trying to figure out
how and where and when
they can get access to it.
So, it's not gonna go away.
And so, I think the broader question is,
how do we approach unintended consequences
of this type of genome
editing in the future,
and there's no easy answer there.
I'm not quite sure how you do experiments
to figure that out.
It's a tough question.
- [Moderator] Yes please.
Right over here.
Yes.
- [Audience Member] Sorry.
So you mentioned earlier
that CRISPR is mostly very accurate.
How does it fail?
Would this failing mean it's sticking that
section of DNA somewhere it shouldn't
or it just can't find
the piece of DNA it's trying to untangle
and it proverbially gives up?
- Right, yeah.
Thank you for that question,
because it's really important.
It fails or it induces
what we call of target changes to DNA
when it engages on a place in the genome
that doesn't maybe perfectly
match the guide RNA sequence,
and that does happen with some frequency.
The frequency of that really
turns out to depend greatly on
the way these molecules are
actually introduced into cells,
the amount of the editor
that it's in the cell,
the time that it stays active in the cell
and all of those sorts of things.
So, it's been a very
active area of research
over the last few years to investigate
off target editing, and how does it work,
and how do we prevent it.
There've been a lot of advances
I would say in the
technology that make me think
that today that's not really
a bottle neck going forward
even for clinical use.
It's not to say that we ignore it,
but we have to pay attention
to the accuracy of the editor,
but there are better and better ways
of both monitoring that,
as well as modified
forms of these proteins
that are even more accurate.
I think the other way to
think about your question
is what about...
And this kinda gets back
to this earlier question
about unintended consequences.
What about edits that are
happening as we intend,
but they lead to a genetic alteration
that has an undesired
or unintended outcome?
So you altered the gene
that you intended to alter,
but it has an unpredictable
or undesired outcome,
and that's a lot harder
to figure out how to test to control for.
- [Moderator] Yes, over
here toward the front.
Please keep your hand up.
Yeah.
Yes.
- [Audience Member] Thank
you for representation.
I'm from a startup community,
so I'd like to hear your view on
how you see the responsibility
and the role of the startups
and venture capital in the ecosystem.
I know that there are so many money
coming to gene editing.
Are you seeing a positive trend
or do you see some risk like startup
or like venture capital
come into this space?
- I had a bit of difficulty
hearing the question.
Were you able to hear it?
- [Moderator] I didn't catch it either.
- Can you just repeat?
Sorry,
- Hi, can you hear me?
Okay, so yeah, I have question about the
how you see the load and
responsibility of startup
and also venture capitals.
There are many money now
coming into that space,
so I wonder if how you see it's positive
or negative trend.
- You're touching on a
very important point,
and that is the...
I didn't get a chance
to talk about it today,
but there's a tremendous
interest in the biotech
and investor communities in
gene editing as a technology
that will enable all sorts
of commercial opportunities.
That's on one hand very exciting
and I think will lead
to important advances,
especially in sort of the
outcomes of this tool.
But at the same time,
it does raise challenges
especially for things like
conflicts of interest, right?
Because people like me
and many of my colleagues
are involved in some of those companies,
and so you could imagine conflicts arising
between the research that we're doing
and the business opportunities
or models of those companies.
So I think it's just
something that we have to be
very cognizant of and paying
very close attention to.
It starts with transparency
about engagements we all have.
But I also think that I wanna
point out that I think there's
very exciting ways of advancing
technology that involve
partnering between
academics and companies.
This is something I really
didn't know anything about,
until a few years ago.
My work had never had any commercial
implications whatsoever in the past,
but I've had to kinda learn about this.
Again, I benefited from a
lot of experts here at Cal
who I've been able to talk to about
different aspects of these
kinds of partnerships.
But I think that there are times when
there is research being
done in academic labs
that has potential commercially
but is going in the direction that
really couldn't be
explored by an academic lab
because we don't have the resources
and frankly we maybe don't have the
desire or the expertise to take the work
in that kind of direction.
So by partnering with companies,
I think we can do things together
that neither party would
be able to do alone.
So I think the challenge is to
look for those opportunities
and always maintaining
transparency necessary to
try to avoid conflicts.
- [Moderator] So I'd like to go back
over here to the quadrant.
- [Audience Member] Hi,
my question was about
what you discuss earlier.
You show that there were
mutations edits that
He Jiankui made to the genome where
where human edits that
had never before been seen
in the human population.
And I was sort of wondering
how you deal with the
consequences of that where,
I mean, obviously,
they've been edited now,
but these are human
beings and they could live
30, 50, a hundred years,
and obviously the genome isn't static
and there's often mutations.
And so, I was wondering,
number one, how you deal with
mutations in a genome that
is different than what
is in the normal population.
And then also if those
children decide to have
their own children,
you now have a lineage of
genetically modified humans that
we've introduced into the population
like how you deal with that going forward
and how that affects sort of
the whole human population.
- Right.
So take the second question first,
I think it's important to appreciate that
introducing a trait like that into
the whole human population
would take a really long time.
I think that's not going to happen.
But you're right that those children now
could pass this trait on to their kids
and it becomes part of
their family lineage.
So, going forward, it will
be essential to, I think,
to monitor these girls'
health as they mature,
and try to figure out how,
as in your first question,
how stable are these edits
and what impact does that genetic
change to their DNA have on their health,
not only in terms of their
susceptibility to infection,
because of the change that could affect
the function of their immune cells,
but also might affect other
aspects of their health.
There's some publications now
and some papers out very
recently that suggests
that the gene that was
edited in these girls,
in addition to affecting
their susceptibility
to HIV infection,
might also affect other
aspects of neural function,
and might in fact be in some
way beneficial to their health.
And so, that will have to
be assessed going forward.
And I think that would have
to be done, in my opinion,
by a third party group external to.
It wouldn't be appropriate
for that to be monitored by,
for the monitoring to be done by the
scientist that actually
did the work, right?
It would need to be done by a third party.
Will that happen?
It's hard to say.
- [Moderator] Toward the front.
Yes, this gentleman right here.
(faintly speaking)
- [Audience Member] Thank you.
I'd like to touch on
eugenics for a minute.
And given the really dark history
in this state in particular,
do you envision the government taking
a harsh stance early on
or do you envision it being
left open to the marketplace?
How do you kind of envision that aspect
of the technology moving forward?
- Well, I guess I imagined that
it's likely to move forward
analogous to the way that
in vitro fertilization
has unfolded.
So, I'm old enough to remember when
my parents would sit at
the dinner table at night
and debate the morality
of test tube babies,
and talk about was it right for people to
be conceived in a test tube.
It seemed really weird.
But then over time, we
had family and friends
who benefited from IVF, and
many other people as well,
and Louise Brown grew up
and she seem to be fine.
So, overtime in a very kind
of grassroots way almost.
People came to accept that technology.
I almost wonder if we'll
see a similar thing
with human germline editing,
that it'll perhaps start to
be used in some IVF clinics,
I hope under much more
stringent regulatory guidelines
than has happened in this first instance.
If those uses results and
perceived the benefits
to kids and to families,
then you could imagine
that that will start to be
more widely adapted.
Now, does that mean that we're
entering into an era of eugenics?
I don't really see that
likely to be happening.
I think that it's probably gonna be more
sporadically utilized.
And I would hope that
initial uses are limited to
real medical need,
rather than what we might
consider to be enhancements.
(faintly speaking)
- [Moderator] Off to the side, yes please.
- [Audience Member] How close are we to
kind of like curing single-gene diseases
like Huntington's that
you're talking about,
and how would you translate
from in the lab to human?
And also, what are the difficulties,
both in the policy side and
the scientific communities,
and just like healthcares
area, like profit-driven?
- So I think your question is about,
you said how closer
are we to being able to
correct a single gene mutation.
Was that your question?
We're already there.
I mean it's amazing,
but we're already there.
So, I can give you just a
couple of fast examples.
I mean, right now in animals,
in mice, it's been possible to
introduce genetic changes that correct
a disease of the liver.
That's been done in a couple of cases.
Eric Olson at the University
of Texas recently published
data showing that in a dog model
of Duchenne muscular dystrophy
you could actually
introduce genetic changes
that alleviated the
phenotype of that disease,
which is it's a crippling
muscular degenerative disorder,
which was really a profound sort of...
He showed these results
at a scientific conference
a few months back and I think
everybody in the room was
just kind of stunned, right?
But how do we go from
that where we are now
with that kind of application in animals
and certainly in all kinds of stem cells
and cells in the laboratory?
How do we go from that to
actually having a treatment
that will be available
and useful for curing patients?
And this is where the expertise
of many folks in the room
goes far beyond what I know,
but you know it's certainly gonna involve
things like we have to
figure out how to deliver
gene editing molecules in the cells
that sort of a scientific
and technical challenge.
But then there's the challenge of the cost
of that kind of treatment.
How affordable will that be?
Who pays for it?
Is this gonna be covered by an insurance
and how do we decide that?
And then who gets accessed to it?
If these are, for
example, patients that are
afflicted with sickle cell disease,
I think we're on the verge of having a
strategy that will actually be curative.
For sickle cell disease,
that's tremendous,
but there's a hundred thousand
people in the US alone
that are afflicted, and then
there's many, many people
in Sub-Saharan Africa that are afflicted.
And so, how do we ensure
that there's sort of
an equitable distribution
of a technology like that
and potentially a cure?
These are profound questions,
and I think they have to be tackled.
Again, there's sort of no easy answers.
- [Moderator] Well, the
microphone is up here.
(faintly speaking)
- [Audience Member] So,
I had a question about
food regulation.
You just discussed how basically
the removal of genes from
food genomes is not
regulated by the US FDA.
Why did they make that judgement,
and do you think that the
removal of a certain gene
can have unintended consequences that
they aren't accounting for?
- Right, so my understanding
of that decision by the US
department of Agriculture is that
they basically look at
genetic changes that are made to a plant,
and they decided that if
there's no introduction
of foreign DNA, then
effectively you could argue that
that genetic knock out is something that
could happen naturally.
You could have plant breeders
you could knock out a gene.
It might take a really long time,
but they could get there through natural,
there could be a natural
process towards that
genetic knockout.
Whereas a knock in where a
new foreign gene, let's say,
that's not been in that
plant before is introduced,
that's much harder to imagine
how that can happen naturally.
So I think that was sort of the
basis of making that decision.
And you might wonder,
well, how come in Europe,
the decision went a different direction?
And I think it's because in Europe
they define genetic
modification according to
just the technology manipulation itself.
If this plant was manipulated
with some kind of a tool
like a gene editing tool,
even if you ended up with
exactly the same plant
at the end of the experiment,
it would still be called
genetically modified
because it went through that process
of being exposed to the technology.
Does that make sense?
It's just different ways of defining
what we consider genetic modification.
But as you can see,
these are all, in a way,
very subjective kinds of decisions.
And I think they're really
gonna come down, in many cases,
to what all of us,
as the consumers of those
potential products really want.
Do people want to have access
to those plant products
that are a product of
genetic manipulation or not.
And my personally feeling there is that
if you think about how
traditional plant breeding works,
it involves mutagenizing plants
and you get lots of random changes to DNA,
and then you simply select
for plants thar have desired traits.
Who knows what other genetic changes
are coming along for the ride,
and as you know, it results
in things like roses
that don't smell nice anymore because
those genes have been lost
in the process of removing
thorns, things like that.
So, I think we have to just,
again, be very thoughtful about
what kind of regulation
we might advocate for,
given the realities of
how the technology works.
- [Moderator] This
gentleman here on the aisle.
- [Adan] Hi, good evening.
My name is Adan Hill.
I'm a former candidate
for Berkeley City Council,
representing this area.
Like many of the constituents
here, I have concerns
about the dual use applicability,
as well as the bioweaponry
available with CRISPR technology.
But I'm curious, has there been any trials
of CRISPR technology with 5G technology?
And what are the circumstances
of cellular radiation
using this technology to
enhance the genome structure?
Thank you.
- Okay, I didn't entirely understand
the details of your question,
but I think you're generally asking about
dual use of genome editing technology
which basically means the
potential for the technology
to be used both for the public
good, but also for harm.
I've had a lot of discussions
about this with people.
We've had a number of visits from
government agencies that
have come to Berkeley
and talked with me and other folks,
as well as our colleagues
around the country
about this question.
I feel that gene editing is,
it's sort of no different than
other technologies that have
the potential to do good and bad.
They have to be monitored
carefully for sure.
I think one of the
challenges with gene editing
and hopefully you took this
away from my talk is that
it's widely available.
It's really easy for
people to get a hold of it.
It's not something you
can lock away in a box.
Even if we wanted to get rid
of it, and I think we don't,
but even if we wanted to say
we're not gonna let scientists
use this anymore for
certain kinds of things,
it's gonna be very very
hard to actually do that.
So I think more effective is gonna be
really just being very
transparent about uses that are
contemplated and getting
the scientific community
to really engage and thinking about
how to work together to
encourage the culture of responsible use.
It's not a perfect solution
but I think it's a good start.
- [Moderator] Rexel, could you
please hand the microphones
to this gentleman
straight across from here?
Down that row, yep.
Thank you.
- [Audience Member] Thank you.
Dr. Doudna, thank you so
much for all your work.
My question is this.
If you know the gene that is a cause
of a particular disease,
and the specific context happens to be
retinal degenerative disease,
and you're able to edit out
the defective part of the gene,
where does the healthy gene
that you're going to replace come from?
If that's an intelligent question.
And then secondly, am I correct that
the CRISPR has two aspects,
precluding the transfer or the inheritance
of a gene that's defective
by editing it out,
but also the ability to get
the new gene, corrected gene,
to express itself so you might
have some immediate effect
in that person?
Thank you very much.
- Yeah, those are both
really great questions,
and the first question is about where...
So, I showed this
example of a piece of DNA
being inserted into a genome
in the process of repairing a break
introduced by this CRISPR-Cas9 protein.
Where does that DNA come from?
That's a great question.
Basically, there's two sources.
One is from the cell itself,
so you probably know that
there are two alleles,
two copies of every
gene in a deployed cell.
And so, you could imagine a scenario where
one of those alleles is
caught by CRISPR-Cas9,
especially if it has a
change in the sequence
that allows specific recognition,
and then you could have
repair by the other allele.
So that's one possibility,
and that's actually been
demonstrated in animals
to be a pathway for a DNA repair.
But in many cases, especially
if we were gonna use
this kind of strategy clinically,
scientists can actually introduce
that DNA repair template
into cells externally.
So they can introduce it
in a virus, for example,
or just some other kind of piece of DNA
that gets introduced into cells
where it provides the
template for DNA repair.
So that's how that's done.
And then your other
question was, remind me,
the second question.
Yes, okay.
Right.
Right, right.
And this is also a great question,
because it really gets at this distinction
between making heritable
changes in the germline
where those changes has
become part of the individual
and can be passed onto the future
children of that individual.
But if we do the editing in sematic cells,
then that means we're
making changes to DNA
in a single individuals,
and maybe just in one
tissue of that individual.
You could imagine some day being able
to treat muscular dystrophy
in patients that have that disease
by just treating their muscle cells,
if you had a way to deliver gene editing
into just those cells.
And then you could actually,
as was done in this dog model,
you could actually turn on production
of the normal protein that's
missing in those people
and in these dogs,
and restore muscle function.
- [Moderator] Thank you, Rexel.
To the young lady with her hand up.
There, please.
- [Audience Member] I
was just raising my hand
for my friend whose arms got tired.
- [Moderator] Alright, that
sounds like a good deal.
(laughs)
Friendship at its best.
- Great.
(audience applauding)
- [Audience Member] So, I was
kinda wondering like, one,
what kind of future do you see
for CRISPR-Cas9 in just
like over-the-counter
sort of cough and cold medicine?
And I was wondering what
would happen if you tried to
defend against mutations from gene editing
by using more gene editing
to put the genes back
how they original were.
- Thank you.
Both of those, again, are
really great questions.
So, how soon are we gonna
see over-the-counter
gene editing?
And I have two answers to that.
One is that we already have that today
if we're not talking about
editing people, right?
Because you can actually,
scientists can go to
a non-profit organization called Addgene.
And for a very inexpensive, very low cost,
they can get access to these
gene-editing molecules,
and they can start doing
experiments in their labs.
In that sense, it's sort
of is over-the-counter.
How soon will that be
you're going to the store and you have a
headache, and you need to buy CRISPR-Cas9?
No, not very soon for lots of reasons,
and it's probably a good thing.
And then your second question was?
Remind me.
Shout it out.
- [Audience Member] Would it be possible
to counteract mutations from gene editing
with more gene editing?
- Yeah.
I think the way I would
answer that is that
I think what you're asking is
once you change the DNA in a
cell, can you change it back?
What do you do?
And so, there's lots of
interest in this right now
in the scientific community.
There's lots of people that are
thinking about that question actually.
How do we think about gene edits
and what if you wanted to turn off
a gene editor that you'd
put into cells, either...
I don't know about reversing
those genetic changes,
that might be harder,
but certainly not allowing the gene editor
to go on indefinitely,
sort of modifying DNA and cells.
And so, there's a really interesting
biological phenomenon.
It turns out that in nature,
as I kinda talked about
in the beginning of my talk,
so these CRISPR enzymes, these proteins
arose as a bacterial
adaptive immune system.
They prevent viral infection in bugs.
Well, you can imagine the viruses
don't like that very much.
And so they fight back.
And they actually make
little proteins that inhibit
the CRISPR enzymes.
So they have inhibitors,
we call these anti-CRISPRs.
And so there's kinda this
natural kinda war going on
between CRISPR proteins and
then these anti-CRISPRs.
And there's lots of
research happening right now
to understand how those work,
but also how you could actually use them
in a protective way in cells
to prevent undesirable genetic changes.
- So, thank you.
Unfortunately, the time has raced by.
We have time for just one more question.
This person in the front row.
(faintly speaking)
- [Audience Member]
Hello, thank you so much.
I was wondering, earlier
you mentioned that
pigs are being genetically engineered
to produce organs for organ donation,
and mosquitoes are being
genetically altered to
either become extinct or become sterile
in terms of spreading disease to humans,
and I was just wondering
what are your thoughts on
the implication of
altering the environment to aid in
the extension of human life expectancy.
- Well, I think in both, those examples,
and especially in the
case of a gene drive,
that could have big
implications environmentally
that could be hard to predict initially.
I think we have to proceed
with extreme caution.
I really favor careful evaluation
under very defined laboratory settings
before proceeding further.
And right now there are a
number of studies going on
in research labs to test
especially gene drives,
and then there's some controlled studies
that are planned in isolated
environmental setting
just to kinda get a sense
of how effective these will really be
in a natural population.
That's something that really
hasn't been explored yet,
but I think the key is
proceeding carefully,
and with a lot of thought
behind each step that's taken.
- Please join me in
thanking Professor Doudna.
(applauding)
