Gene-Edited Animals as Trailblazers

By Jon Holmlund


The Chinese researcher who says he edited the genes of two recently-born twin girls is named He.  He’s not a deity, that’s just his name.  (I don’t think it’s pronounced with a long “e,” by the way.)  His motivation appears to have been to be the first, to show that He could really do it. 

While scorn is mostly being heaped on He, this work has been going on in livestock for a long time, in attempts to make animals with leaner meat, or more meat, or ones that are disease-resistant, or more tolerant to hot or cold weather, or ones that have softer or more durable fur for shearing and making into cloth.  Or, cattle could be altered so they don’t have horns, and don’t have to be dehorned after birth.

Proponents consider this work to be just like crossbreeding, only a lot faster.  That’s an oversimplification, of course, since cross-breeding follows naturally occurring processes of genetic modification, not the synthetic editing of specific genes, but for the moment that’s beside the point.  The agriculture industry is keenly interested in it—the potential could be large.  Some governments want to push it.  Which ones?  You guessed it—China—but also the US, as part of the current administration’s efforts to reduce regulation and foster innovation.

Reportedly, some of these animals’ meat has been tested, and found safe.  (No claim, yet, that it’s delicious.)  But nothing commercial, at least not yet in the U.S.

One problem, though:  the animals have unpredicted other abnormalities.  Some pigs edited to be meatier also had an extra vertebra in their spines.  Some rabbits similarly edited had unusually large tongues.  And the edited animals often don’t make it to live birth, or even implant into adult females to cause pregnancy.  The process sometimes uses cloning to create the animal embryos in the first place, and it’s speculated that the cloning process, not the specific gene editing, is causing the problems with pregnancy.  But that’s not for certain.

In recent decades there has been a hue and cry over the safety of genetically modified plant foods, but they appear to be safe for human consumption, and they don’t fundamentally alter the biosphere.  The meat or milk or fur of genetically engineered animals would seem likely to be safe for human use, also, and if the animals really are created just for human use, some bizarre deformities may not be so objectionable.

Of course, that prompts questions of animal use and welfare that require more than a short blog post.  But in the case of humans, we would anticipate living with and caring for gene-edited offspring.  We would not be producing them solely for use or consumption.  Or would we—for example, for organs to transplant?  Probably not.

Proponents of limiting the use of artificial human reproductive techniques sometimes argue that it is good for children to be received as gifts, and that, rather than being “ordered to specification,” their specific characteristics be welcomed as something of a surprise.  I suppose that off-target effects of heritable human gene editing could prove to be surprises, indeed.

One scientist quoted in the general press says that, regarding editing animals, ‘if we don’t try, we will never learn.” Another, an animal advocate, says, again about the animal work, “I think it would be an understatement to say we should be more cautious…I think we’ve already gone over the line with animals, and now humans.”

For sure, and now, with humans, a major question will be, how will we regard and handle the mistakes?

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