CRISPR-driven research; philanthropies have granted millions more
to support scientists working on cures for genetic diseases; and in
China, at least seven human clinical trials are moving forward. But it
all started when a small group of scientists, working in collaboration,
stumbled on an organic biological process that had existed for millennia. Among the leaders was molecular biologist Jennifer Doudna, who
heads the Doudna Lab at the University of California, Berkeley. She’s the
coauthor of a new book tracing CRISPR’s evolution, A Crack in Creation:
Gene Editing and the Unthinkable Power to Control Evolution. “[CRISPR]
is a great illustration of how technologies are born,” says Doudna.
“They often come about in unexpected ways.” And the outcomes can
be just as unpredictable, and dangerous—a fact that has prompted her
to become a global advocate for the responsible use of CRISPR. In this
excerpt, Doudna talks about its transformative power. —Noah Robischon
Tomatoes that can sit in the pantry slowly ripening for months without
rotting. Plants that can better weather climate change. Mosquitoes that
are unable to transmit malaria. Ultra-muscular dogs that make fearsome partners for police and soldiers. Cows that no longer grow horns.
These organisms might sound far-fetched, but in fact, they already
exist, thanks to gene editing. And they’re only the beginning. As I write
this, the world around us is being revolutionized by CRISPR, whether
we’re ready for it or not. Within the next few years, this new biotechnology will give us higher-yielding crops, healthier livestock, and more
nutritious foods. Within a few decades, we might well have genetically
engineered pigs that can serve as human organ donors—but we could
also have woolly mammoths, winged lizards, and unicorns. No, I am
It amazes me to realize that we are on the cusp of a new era in the
history of life on earth—an age in which humans exercise an unprecedented level of control over the genetic composition of the species
that coinhabit our planet. It won’t be long before CRISPR allows us to
bend nature to our will in the way that humans have dreamed of since
prehistory. When that will is directed toward something constructive,
the results could be fantastic—but they might also have unintentional
or even calamitous consequences.
The impact of gene-edited plants and animals is already being
felt in the scientific community. For example, researchers have harnessed CRISPR to generate animal models of human disease with far
greater precision and flexibility than before—not just in mice, but in
whatever animals best exhibit the disease of interest, whether it be
monkeys for autism, pigs for Parkinson’s, or ferrets for influenza. One
of the most interesting aspects of the CRISPR technology is the way
it enables the study of features unique to certain organisms, such as
limb regeneration in Mexican salamanders, aging in killifish, and
skeletal development in crustaceans. I love the notes and pictures
colleagues send me describing their CRISPR experiments—the beautiful butterfly-wing patterns whose genetic underpinnings they’ve
uncovered, or the infectious yeast whose ability to invade human
tissues they’ve dissected at the level of individual genes. These kinds
of experiments reveal new truths about the natural world and about
the genetic similarities that bind all organisms together. They’re
enormously exciting to me.
At the other end of the spectrum are gene-editing applications that
read more like science fiction than the contents of a scientific journal.
Next Innovation Agent
Researchers at South Carolina’s
Clemson University are employing CRISPR to create citrus trees
that are resistant to a disease
known as Huanglongbing, or
citrus greening, which has devastated the country’s industry
over the past decade.
Using a gene-editing tool
called TALEN, Minneapolis-based Calyxt has developed
soybeans with “an overall fat
profile similar to that of olive
oil,” Doudna writes. The company plans to launch commercial soybean oil next year.
The University of Missouri has
bred pigs that are resistant to
porcine reproductive and respiratory syndrome. “The virus
costs U.S. pork producers more
than $500 million annually,”
Doudna writes, “and reduces
production by 15%.”
Chinese scientists have applied
CRISPR to suppress the gene
that controls hair growth in
Shanbei goats, prized for their
cashmere wool. The enhanced
goats produce a third more fur
than their counterparts.
Researchers in China are
harnessing CRISPR to create
monkeys that mimic human
conditions and diseases, from
muscular dystrophy to cancer,
which would allow “scientists
to hunt for disease cures
without endangering human
lives,” Doudna writes.
A team in Australia is exploring
ways to rewrite the chicken
genome to eliminate the proteins that cause egg allergies
in humans. The new eggs could
be used in foods and vaccines.
Since CRISPR’s discovery, scientists around the world have
been finding new ways to apply gene editing to plants and
animals. Here are some of the developments Doudna tracks
in A Crack in Creation.