MAY 2019. DISCOVER 29T
ranslucent sperm wriggle slowly across
a sepia-toned laptop screen. Normally
they’re much faster, the embryologist
tells me, but these little guys are slogging
through a gooey liquid that slows them down. It
makes them easier to catch.
A skinny, hollow needle enters the scene from
screen right and approaches a swimmer. The
device sucks it inside, tail first. Its tiny, round body
remains visible inside the clear sperm vacuum.
The screen blinks to a new scene. The sperm
disappear and are replaced by much larger, free-
floating eggs. Human eggs.
Another instrument arrives on screen, nudging
one of the eggs until it floats away like a gently
bumped beach ball. After another try, the finger-
like device successfully grabs an egg, using gentle
suction to hold it in place.
The producer of this show is researcher Nuria
Marti-Gutierrez, who sits at the microscope near
the screen, never taking her eyes off her quarry as
her hands maneuver between a half-dozen knobs
and dials. The process she’s running is invisible to
the naked eye. Each of these acts plays out in a clear
droplet on the microscopic stage.
Off screen, the sperm vacuum makes a quick
pit stop to grab an additional solution beforeappearing again, poised and ready. In a moment,
the egg will be injected not only with sperm but
with a dose of CRISPR-Cas9, a DNA editing
system that allows scientists to cut out a gene seg-
ment and replace it with another. If all goes well,
the CRISPR system will cause this single-celled
human embryo to repair a disease-causing muta-
tion in its DNA.
This lab, at Oregon Health and Science
University (OHSU) in Portland, is the only group
in the U.S. to publish this kind of research in
human embryos. The scientists are researching
human gene editing in hopes of curing specific
inherited diseases. Since their claims in 2017 to
have successfully repaired embryos that had a
disease-causing mutation, they’ve faced backlash
from skeptical scientists and opponents of human
gene editing. Now, after a Chinese researcher
announced the birth of gene-edited twin girls in
late 2018, they will have even more hurdles to clear
before they can bring their technology to clinics.TWINS BORN
Perhaps no one was more surprised at the
news that gene-edited babies had been born
in China than the OHSU team at the Center
for Embryonic Cell and Gene Therapy, led byA RESEARCH TEAM IN OREGON HOPES
GENE EDITING TECHNOLOGY WILL PUT
AN END TO INHERITED DISEASES.REPAIRING
THE FUTURE
BY ANNA GROVES