Open season for gene-editing animals

With the recent FDA approval of genetically modified salmon as safe for human consumption, the gene-editing animal industry has been given a massive boost, despite ethical reservations. The new techniques have reduced the cost and increased the ease of genetically engineering DNA, leading to positive breakthroughs including malaria-proof mosquitoes and swine fever resistant pigs. Also in development are breeding animals for the food chain, including gene-edited pigs that can be fattened with less food, and more tender and meat-yielding Brazilian beef cattle. However, with no stated regulation from the FDA, public perceptions and approval may be the deciding factor whether the gene-editing industry reaches its potential as farmers will be wary of consumer rejection. 

SIOUX CENTER, Iowa — Other than the few small luxuries afforded them, like private access to a large patch of grass, there was nothing to mark the two hornless dairy calves born last spring at a breeding facility here as early specimens in a new era of humanity’s dominion over nature.

But unlike a vast majority of their dairy brethren, these calves, both bulls, will never sprout horns. That means they will not need to undergo dehorning, routinely performed by farmers to prevent injuries and a procedure that the American Veterinary Medical Association says is “considered to be quite painful.”

Instead, when the calves were both just a single cell in a petri dish, scientists at a start-up company called Recombinetics used the headline-grabbing new tools of gene editing to swap out the smidgen of genetic code that makes dairy cattle have horns for the one that makes Angus beef cattle have none. And the tweak, copied into all of their cells through the normal machinery of DNA replication, will also be passed on to subsequent generations.

“It’s pretty cool,” said Micah Schouten, the calves’ caretaker, looking at his charges.

The uproar over the new ease and precision with which scientists can manipulate the DNA of living things has centered largely on the complicated prospect of editing human embryos. But with the federal government’s approval last week of a fast-growing salmon as the first genetically altered animal Americans can eat, a menagerie of gene-edited animals is already being raised on farms and in laboratories around the world — some designed for food, some to fight disease, some, perhaps, as pets.