ABOVE: Genome-edited bull Buri (top row) was mated with six female horned cows (middle row) and sired six calves (bottom row).
FROM FIGURE 2 OF NAT BIOTECHNOL, DOI:10.1038/S41587-019-0266-0, 2019.
A genetically edited bull successfully passed down to his offspring a gene that scientists had introduced into his genome as an embryo so that he would not grow horns as an adult, scientists reported Monday (October 7) in Nature Biotechnology. The six calves—which, at two years of age, are perfectly healthy, the researchers report—are expected to lack the dangerous horns that are often removed from dairy cows in a process that is labor-intensive, costly, and dangerous itself.
Four of the calves also inherited a bit of the plasmid that had ferried the hornless gene, called POLLED, into the bull’s genome. The unintended presence of foreign DNA has derailed their route to market in Brazil and the US.
“We’ve demonstrated that healthy hornless ...