ety isn’t aware of it,” says Kagimoto. “Don’t get me wrong,
though—if we do anything, we’ll do it with the consensus of
Although he has patented his inventions, Hayashi so
far hasn’t been willing to join a company. He says that last
November, Japanese venture capitalists asked him to start
one to make human eggs. “I refused. I refused because I can’t
do it yet. Mainly it’s because it’s technically di;cult,” he says.
“But it’s also too immature to contribute to society.” Surveys
in Japan show about 30 percent of people accept the idea of
children from lab-made gametes. Support is highest for use
by couples who have tried IVF and failed.
Some investors see far wider possibilities. If eggs could
be made from human iPS cells, the supply would potentially
be limitless, perhaps leading to what is sometimes called
“embryo farming.” Kagimoto remarked on one of the images
in Hayashi’s publications. It is a picture taken through a
microscope of dozens of lab-made mouse eggs floating in a
drop of water.
In that case, genetic sequencing could be used to inspect
each embryo, allowing people to choose the “best” ones—
those with desirable genes or without undesirable ones, like
those associated with a risk of schizophrenia. This is the scenario predicted by Greely, the legal scholar, who argues that
parents would choose artificial reproduction over sexual
reproduction if they had enough to gain. “If you have 1,000
eggs, then you can make choices,” Kagimoto says.
BRAVE NEW WORLD
During the Boston stem-cell meeting, students strained from
the doorways to hear presentations on the ethical issues
raised by new reproductive technologies. From the podium,
Daley cited Aldous Huxley’s 1932 book Brave New World,
which described a society that controlled reproduction and
incubated children in centralized facilities. The picture
Huxley drew was dystopian but also “prescient,” said Daley. It
Daley believes scientific advances will allow for scenarios not unlike the one Huxley described. In addition to the
Japanese e;orts to create gametes, some scientists have created “gastruloids”—self-assembling blobs of cells that look,
and behave, much like human embryos. At the same time,
researchers are pressing on nature from the other direction.
In February, doctors in Philadelphia removed fetal lambs
from their mothers and kept each alive until birth inside a
transparent fluid-filled sac known as an artificial uterus. The
combination of these technologies points to a day when the
entire reproduction process, from conception to birth, can
“One only has to speculate how
long it is going to be before we
can gestate animals entirely
ectogenetically, entirely ex utero.
So the question then becomes:
Can you draw the line?”