ABOUT THE SPEAKER
Jennifer Doudna - Biologist
Jennifer Doudna was part of inventing a potentially world-changing genetic technology: the gene editing technology CRISPR-Cas9.

Why you should listen

Together with her colleague Emmanuelle Charpentier of Umeå University in Sweden, Berkeley biologist Jennifer Doudna is at the center of one of today's most-discussed science discoveries: a technology called CRISPR-Cas9 that allows human genome editing by adding or removing genetic material at will. This enables fighting genetic diseases (cutting out HIV, altering cancer cells) as well as, potentially, opening the road to "engineered humans."

Because some applications of genetic manipulation can be inherited, Doudna and numerous colleagues have called for prudent use of the technology until the ethics and safety have been properly considered.

Doudna is the co-winner of the 2018 Kavli Prize in Nanoscience, along with Emmanuelle Charpentier and Virginijus Šikšnys.

More profile about the speaker
Jennifer Doudna | Speaker | TED.com
TEDGlobal>London

Jennifer Doudna: How CRISPR lets us edit our DNA

Filmed:
2,870,405 views

Geneticist Jennifer Doudna co-invented a groundbreaking new technology for editing genes, called CRISPR-Cas9. The tool allows scientists to make precise edits to DNA strands, which could lead to treatments for genetic diseases ... but could also be used to create so-called "designer babies." Doudna reviews how CRISPR-Cas9 works -- and asks the scientific community to pause and discuss the ethics of this new tool.
- Biologist
Jennifer Doudna was part of inventing a potentially world-changing genetic technology: the gene editing technology CRISPR-Cas9. Full bio

Double-click the English transcript below to play the video.

00:13
A few years ago,
0
1303
1160
00:14
with my colleague, Emmanuelle Charpentier,
1
2487
2770
00:17
I invented a new technology
for editing genomes.
2
5281
3258
00:21
It's called CRISPR-Cas9.
3
9093
2114
00:23
The CRISPR technology allows
scientists to make changes
4
11870
3576
00:27
to the DNA in cells
5
15470
1855
00:29
that could allow us
to cure genetic disease.
6
17349
2906
00:33
You might be interested to know
7
21196
1492
00:34
that the CRISPR technology came about
through a basic research project
8
22712
3784
00:38
that was aimed at discovering
how bacteria fight viral infections.
9
26520
3943
00:43
Bacteria have to deal with viruses
in their environment,
10
31340
2872
00:46
and we can think about a viral infection
like a ticking time bomb --
11
34236
3664
00:49
a bacterium has only a few minutes
to defuse the bomb
12
37924
3358
00:53
before it gets destroyed.
13
41306
1610
00:55
So, many bacteria have in their cells
an adaptive immune system called CRISPR,
14
43284
5390
01:00
that allows them to detect
viral DNA and destroy it.
15
48698
3646
01:05
Part of the CRISPR system
is a protein called Cas9,
16
53148
3968
01:09
that's able to seek out, cut
and eventually degrade viral DNA
17
57140
5949
01:15
in a specific way.
18
63113
1262
01:17
And it was through our research
19
65054
1502
01:18
to understand the activity
of this protein, Cas9,
20
66580
3657
01:22
that we realized that we could
harness its function
21
70261
2831
01:25
as a genetic engineering technology --
22
73116
3406
01:28
a way for scientists to delete or insert
specific bits of DNA into cells
23
76546
6951
01:35
with incredible precision --
24
83521
2031
01:37
that would offer opportunities
25
85576
1667
01:39
to do things that really haven't
been possible in the past.
26
87267
3072
01:43
The CRISPR technology
has already been used
27
91184
2062
01:45
to change the DNA in the cells
of mice and monkeys,
28
93270
5084
01:50
other organisms as well.
29
98378
1625
01:52
Chinese scientists showed recently
30
100527
1755
01:54
that they could even use
the CRISPR technology
31
102306
2159
01:56
to change genes in human embryos.
32
104489
2629
01:59
And scientists in Philadelphia showed
they could use CRISPR
33
107142
3143
02:02
to remove the DNA
of an integrated HIV virus
34
110309
4843
02:07
from infected human cells.
35
115176
2195
02:10
The opportunity to do this kind
of genome editing
36
118217
3131
02:13
also raises various ethical issues
that we have to consider,
37
121372
3283
02:16
because this technology can be employed
not only in adult cells,
38
124679
3968
02:20
but also in the embryos of organisms,
39
128671
2603
02:23
including our own species.
40
131298
3000
02:26
And so, together with my colleagues,
41
134767
1998
02:28
I've called for a global conversation
about the technology that I co-invented,
42
136789
4488
02:33
so that we can consider all of the ethical
and societal implications
43
141301
4540
02:37
of a technology like this.
44
145865
1724
02:40
What I want to do now is tell you
what the CRISPR technology is,
45
148056
4939
02:45
what it can do,
46
153019
1454
02:46
where we are today
47
154497
1245
02:47
and why I think we need to take
a prudent path forward
48
155766
3022
02:50
in the way that we employ this technology.
49
158812
2353
02:55
When viruses infect a cell,
they inject their DNA.
50
163085
3746
02:59
And in a bacterium,
51
167363
1476
03:00
the CRISPR system allows that DNA
to be plucked out of the virus,
52
168863
4865
03:05
and inserted in little bits
into the chromosome --
53
173752
3845
03:09
the DNA of the bacterium.
54
177621
1950
03:11
And these integrated bits of viral DNA
get inserted at a site called CRISPR.
55
179937
5350
03:18
CRISPR stands for clustered regularly
interspaced short palindromic repeats.
56
186032
5995
03:24
(Laughter)
57
192051
1001
03:25
A big mouthful -- you can see why
we use the acronym CRISPR.
58
193076
3373
03:28
It's a mechanism that allows cells
to record, over time,
59
196890
3988
03:32
the viruses they have been exposed to.
60
200902
2682
03:35
And importantly, those bits of DNA
are passed on to the cells' progeny,
61
203608
4683
03:40
so cells are protected from viruses
not only in one generation,
62
208315
4533
03:44
but over many generations of cells.
63
212872
2349
03:47
This allows the cells
to keep a record of infection,
64
215245
4285
03:51
and as my colleague,
Blake Wiedenheft, likes to say,
65
219554
2939
03:54
the CRISPR locus is effectively
a genetic vaccination card in cells.
66
222517
4956
04:00
Once those bits of DNA have been inserted
into the bacterial chromosome,
67
228572
4498
04:05
the cell then makes a little copy
of a molecule called RNA,
68
233094
4199
04:09
which is orange in this picture,
69
237317
2015
04:11
that is an exact replicate
of the viral DNA.
70
239356
4717
04:16
RNA is a chemical cousin of DNA,
71
244502
2336
04:18
and it allows interaction
with DNA molecules
72
246862
3953
04:22
that have a matching sequence.
73
250839
1999
04:25
So those little bits of RNA
from the CRISPR locus
74
253258
3909
04:29
associate -- they bind --
to protein called Cas9,
75
257191
3789
04:33
which is white in the picture,
76
261004
1935
04:34
and form a complex that functions
like a sentinel in the cell.
77
262963
4219
04:39
It searches through all
of the DNA in the cell,
78
267206
3414
04:42
to find sites that match
the sequences in the bound RNAs.
79
270644
4252
04:46
And when those sites are found --
80
274920
1635
04:48
as you can see here,
the blue molecule is DNA --
81
276579
3470
04:52
this complex associates with that DNA
82
280073
2849
04:54
and allows the Cas9 cleaver
to cut up the viral DNA.
83
282946
5302
05:00
It makes a very precise break.
84
288272
2356
05:04
So we can think of the Cas9 RNA
sentinel complex
85
292096
4400
05:08
like a pair of scissors
that can cut DNA --
86
296520
3181
05:11
it makes a double-stranded break
in the DNA helix.
87
299725
3236
05:14
And importantly,
this complex is programmable,
88
302985
3982
05:18
so it can be programmed to recognize
particular DNA sequences,
89
306991
5200
05:24
and make a break in the DNA at that site.
90
312215
3027
05:27
As I'm going to tell you now,
91
315928
1580
05:29
we recognized that that activity
could be harnessed for genome engineering,
92
317532
4776
05:34
to allow cells to make
a very precise change to the DNA
93
322332
4227
05:38
at the site where
this break was introduced.
94
326583
2472
05:41
That's sort of analogous
95
329558
1215
05:42
to the way that we use
a word-processing program
96
330797
2708
05:45
to fix a typo in a document.
97
333529
2280
05:49
The reason we envisioned using
the CRISPR system for genome engineering
98
337541
4818
05:54
is because cells have the ability
to detect broken DNA
99
342383
3619
05:58
and repair it.
100
346026
1192
05:59
So when a plant or an animal cell detects
a double-stranded break in its DNA,
101
347780
4931
06:04
it can fix that break,
102
352735
1597
06:06
either by pasting together
the ends of the broken DNA
103
354356
3527
06:09
with a little, tiny change
in the sequence of that position,
104
357907
4110
06:14
or it can repair the break by integrating
a new piece of DNA at the site of the cut.
105
362041
6283
06:21
So if we have a way to introduce
double-stranded breaks into DNA
106
369054
4973
06:26
at precise places,
107
374051
1580
06:27
we can trigger cells
to repair those breaks,
108
375655
2809
06:30
by either the disruption or incorporation
of new genetic information.
109
378488
5023
06:35
So if we were able to program
the CRISPR technology
110
383936
3242
06:39
to make a break in DNA
111
387202
2323
06:41
at the position at or near a mutation
causing cystic fibrosis, for example,
112
389549
6269
06:47
we could trigger cells
to repair that mutation.
113
395842
3505
06:52
Genome engineering is actually not new,
it's been in development since the 1970s.
114
400464
5103
06:57
We've had technologies for sequencing DNA,
115
405591
2751
07:00
for copying DNA,
116
408366
1595
07:01
and even for manipulating DNA.
117
409985
2380
07:04
And these technologies
were very promising,
118
412969
3136
07:08
but the problem was
that they were either inefficient,
119
416129
4406
07:12
or they were difficult enough to use
120
420559
2333
07:14
that most scientists had not adopted them
for use in their own laboratories,
121
422916
4802
07:19
or certainly for many
clinical applications.
122
427742
4165
07:24
So, the opportunity to take a technology
like CRISPR and utilize it has appeal,
123
432722
7000
07:32
because of its relative simplicity.
124
440101
3001
07:35
We can think of older
genome engineering technologies
125
443126
3769
07:38
as similar to having
to rewire your computer
126
446919
3659
07:42
each time you want to run
a new piece of software,
127
450602
3770
07:46
whereas the CRISPR technology
is like software for the genome,
128
454396
3764
07:50
we can program it easily,
using these little bits of RNA.
129
458184
3486
07:54
So once a double-stranded
break is made in DNA,
130
462658
3093
07:57
we can induce repair,
131
465775
2087
07:59
and thereby potentially achieve
astounding things,
132
467886
3446
08:03
like being able to correct mutations
that cause sickle cell anemia
133
471356
4159
08:07
or cause Huntington's Disease.
134
475539
2351
08:09
I actually think that the first
applications of the CRISPR technology
135
477914
3461
08:13
are going to happen in the blood,
136
481399
2269
08:15
where it's relatively easier
to deliver this tool into cells,
137
483692
4753
08:20
compared to solid tissues.
138
488469
2121
08:23
Right now, a lot of the work
that's going on
139
491905
2404
08:26
applies to animal models
of human disease, such as mice.
140
494333
3969
08:30
The technology is being used to make
very precise changes
141
498326
3269
08:33
that allow us to study the way
that these changes in the cell's DNA
142
501619
5171
08:38
affect either a tissue or,
in this case, an entire organism.
143
506814
4320
08:43
Now in this example,
144
511515
1207
08:44
the CRISPR technology
was used to disrupt a gene
145
512746
3793
08:48
by making a tiny change in the DNA
146
516563
2767
08:51
in a gene that is responsible
for the black coat color of these mice.
147
519354
4444
08:56
Imagine that these white mice
differ from their pigmented litter-mates
148
524219
5018
09:01
by just a tiny change at one gene
in the entire genome,
149
529261
4667
09:05
and they're otherwise completely normal.
150
533952
1990
09:07
And when we sequence the DNA
from these animals,
151
535966
2891
09:10
we find that the change in the DNA
152
538881
2626
09:13
has occurred at exactly the place
where we induced it,
153
541531
3142
09:16
using the CRISPR technology.
154
544697
1762
09:19
Additional experiments
are going on in other animals
155
547662
2724
09:22
that are useful for creating models
for human disease,
156
550410
4095
09:26
such as monkeys.
157
554529
1603
09:28
And here we find
that we can use these systems
158
556156
3226
09:31
to test the application of this technology
in particular tissues,
159
559406
3802
09:35
for example, figuring out how to deliver
the CRISPR tool into cells.
160
563232
5073
09:40
We also want to understand better
161
568329
2148
09:42
how to control the way
that DNA is repaired after it's cut,
162
570501
3627
09:46
and also to figure out how to control
and limit any kind of off-target,
163
574152
5681
09:51
or unintended effects
of using the technology.
164
579857
3237
09:56
I think that we will see
clinical application of this technology,
165
584356
6150
10:02
certainly in adults,
166
590530
1512
10:04
within the next 10 years.
167
592066
1603
10:05
I think that it's likely
that we will see clinical trials
168
593693
3134
10:08
and possibly even approved
therapies within that time,
169
596851
3429
10:12
which is a very exciting thing
to think about.
170
600304
2713
10:15
And because of the excitement
around this technology,
171
603041
2501
10:17
there's a lot of interest
in start-up companies
172
605566
3293
10:20
that have been founded
to commercialize the CRISPR technology,
173
608883
4762
10:25
and lots of venture capitalists
174
613669
1489
10:27
that have been investing
in these companies.
175
615182
2572
10:31
But we have to also consider
176
619242
1573
10:32
that the CRISPR technology can be used
for things like enhancement.
177
620839
3622
10:36
Imagine that we could try
to engineer humans
178
624485
3044
10:39
that have enhanced properties,
such as stronger bones,
179
627553
4435
10:44
or less susceptibility
to cardiovascular disease
180
632012
4071
10:48
or even to have properties
181
636107
1511
10:49
that we would consider maybe
to be desirable,
182
637642
2399
10:52
like a different eye color
or to be taller, things like that.
183
640065
4441
10:57
"Designer humans," if you will.
184
645942
1846
11:00
Right now, the genetic information
185
648780
2390
11:03
to understand what types of genes
would give rise to these traits
186
651194
4493
11:07
is mostly not known.
187
655711
1733
11:09
But it's important to know
188
657468
1246
11:10
that the CRISPR technology gives us a tool
to make such changes,
189
658738
4285
11:15
once that knowledge becomes available.
190
663047
2507
11:18
This raises a number of ethical questions
that we have to carefully consider,
191
666651
4111
11:22
and this is why I and my colleagues
have called for a global pause
192
670786
4215
11:27
in any clinical application
of the CRISPR technology in human embryos,
193
675025
4746
11:31
to give us time
194
679795
1151
11:32
to really consider all of the various
implications of doing so.
195
680970
4377
11:37
And actually, there is an important
precedent for such a pause
196
685743
3843
11:41
from the 1970s,
197
689610
1319
11:42
when scientists got together
198
690953
1864
11:44
to call for a moratorium
on the use of molecular cloning,
199
692841
3830
11:48
until the safety of that technology
could be tested carefully and validated.
200
696695
5955
11:55
So, genome-engineered humans
are not with us yet,
201
703506
5140
12:00
but this is no longer science fiction.
202
708670
2647
12:04
Genome-engineered animals and plants
are happening right now.
203
712179
4365
12:09
And this puts in front of all of us
a huge responsibility,
204
717069
4053
12:13
to consider carefully
both the unintended consequences
205
721146
4577
12:17
as well as the intended impacts
of a scientific breakthrough.
206
725747
4046
12:22
Thank you.
207
730190
1152
12:23
(Applause)
208
731366
4000
12:31
(Applause ends)
209
739572
1163
12:33
Bruno Giussani: Jennifer, this is
a technology with huge consequences,
210
741535
3894
12:37
as you pointed out.
211
745453
1151
12:38
Your attitude about asking for a pause
or a moratorium or a quarantine
212
746628
5172
12:43
is incredibly responsible.
213
751824
2020
12:46
There are, of course,
the therapeutic results of this,
214
754733
2548
12:49
but then there are the un-therapeutic ones
215
757305
2150
12:51
and they seem to be the ones
gaining traction,
216
759479
2180
12:53
particularly in the media.
217
761683
1246
12:54
This is one of the latest issues
of The Economist -- "Editing humanity."
218
762953
4166
12:59
It's all about genetic enhancement,
it's not about therapeutics.
219
767143
3819
13:03
What kind of reactions
did you get back in March
220
771541
2282
13:05
from your colleagues in the science world,
221
773847
2017
13:07
when you asked or suggested
222
775888
1358
13:09
that we should actually pause this
for a moment and think about it?
223
777270
3316
13:13
Jennifer Doudna: My colleagues
were actually, I think, delighted
224
781054
3001
13:16
to have the opportunity
to discuss this openly.
225
784079
2245
13:18
It's interesting that as I talk to people,
226
786348
2346
13:20
my scientific colleagues
as well as others,
227
788718
2468
13:23
there's a wide variety
of viewpoints about this.
228
791210
2310
13:25
So clearly it's a topic that needs
careful consideration and discussion.
229
793544
3674
13:29
BG: There's a big meeting
happening in December
230
797242
2215
13:31
that you and your colleagues are calling,
231
799481
1976
13:33
together with the National Academy
of Sciences and others,
232
801481
2767
13:36
what do you hope will come
out of the meeting, practically?
233
804272
3292
13:39
JD: Well, I hope that we can air the views
234
807588
2366
13:41
of many different individuals
and stakeholders
235
809978
3600
13:45
who want to think about how to use
this technology responsibly.
236
813602
4292
13:49
It may not be possible to come up with
a consensus point of view,
237
817918
3102
13:53
but I think we should at least understand
238
821044
1993
13:55
what all the issues are as we go forward.
239
823061
1972
13:57
BG: Now, colleagues of yours,
240
825057
1406
13:58
like George Church,
for example, at Harvard,
241
826487
2079
14:00
they say, "Yeah, ethical issues basically
are just a question of safety.
242
828590
3436
14:04
We test and test and test again,
in animals and in labs,
243
832050
2654
14:06
and then once we feel it's safe enough,
we move on to humans."
244
834728
3916
14:10
So that's kind of the other
school of thought,
245
838668
2581
14:13
that we should actually use
this opportunity and really go for it.
246
841273
3148
14:16
Is there a possible split happening
in the science community about this?
247
844445
3778
14:20
I mean, are we going to see
some people holding back
248
848247
2460
14:22
because they have ethical concerns,
249
850731
1794
14:24
and some others just going forward
250
852549
1687
14:26
because some countries under-regulate
or don't regulate at all?
251
854260
3296
14:29
JD: Well, I think with any new technology,
especially something like this,
252
857580
3845
14:33
there are going to be
a variety of viewpoints,
253
861449
2785
14:36
and I think that's
perfectly understandable.
254
864258
3341
14:39
I think that in the end,
255
867623
1512
14:41
this technology will be used
for human genome engineering,
256
869159
4951
14:46
but I think to do that without careful
consideration and discussion
257
874134
4317
14:50
of the risks and potential complications
258
878475
2937
14:53
would not be responsible.
259
881436
1539
14:54
BG: There are a lot of technologies
and other fields of science
260
882999
2979
14:58
that are developing exponentially,
pretty much like yours.
261
886002
2771
15:00
I'm thinking about artificial
intelligence, autonomous robots and so on.
262
888797
4033
15:05
No one seems --
263
893199
1167
15:06
aside from autonomous warfare robots --
264
894390
2508
15:08
nobody seems to have launched
a similar discussion in those fields,
265
896922
4705
15:13
in calling for a moratorium.
266
901651
1410
15:15
Do you think that your discussion may
serve as a blueprint for other fields?
267
903085
4071
15:19
JD: Well, I think it's hard for scientists
to get out of the laboratory.
268
907180
3519
15:22
Speaking for myself,
269
910723
1153
15:23
it's a little bit
uncomfortable to do that.
270
911900
2616
15:26
But I do think that being involved
in the genesis of this
271
914540
3914
15:30
really puts me and my colleagues
in a position of responsibility.
272
918478
3856
15:34
And I would say that I certainly hope
that other technologies
273
922358
3430
15:37
will be considered in the same way,
274
925812
2646
15:40
just as we would want to consider
something that could have implications
275
928482
3398
15:43
in other fields besides biology.
276
931904
1927
15:45
BG: Jennifer, thanks for coming to TED.
277
933855
1952
15:47
JD: Thank you.
278
935831
1261
15:49
(Applause)
279
937116
3693

▲Back to top

ABOUT THE SPEAKER
Jennifer Doudna - Biologist
Jennifer Doudna was part of inventing a potentially world-changing genetic technology: the gene editing technology CRISPR-Cas9.

Why you should listen

Together with her colleague Emmanuelle Charpentier of Umeå University in Sweden, Berkeley biologist Jennifer Doudna is at the center of one of today's most-discussed science discoveries: a technology called CRISPR-Cas9 that allows human genome editing by adding or removing genetic material at will. This enables fighting genetic diseases (cutting out HIV, altering cancer cells) as well as, potentially, opening the road to "engineered humans."

Because some applications of genetic manipulation can be inherited, Doudna and numerous colleagues have called for prudent use of the technology until the ethics and safety have been properly considered.

Doudna is the co-winner of the 2018 Kavli Prize in Nanoscience, along with Emmanuelle Charpentier and Virginijus Šikšnys.

More profile about the speaker
Jennifer Doudna | Speaker | TED.com

Data provided by TED.

This site was created in May 2015 and the last update was on January 12, 2020. It will no longer be updated.

We are currently creating a new site called "eng.lish.video" and would be grateful if you could access it.

If you have any questions or suggestions, please feel free to write comments in your language on the contact form.

Privacy Policy

Developer's Blog

Buy Me A Coffee