Edited animals are in the news this week. Wired dedicates its cover story to “A more human livestock industry, brought to you by CRISPR,” focusing on experiments being done at the University of California, Davis. Alison Van Eenennaam is trying to alter sexual traits in cattle by targeting a single gene called SRY. The science is still difficult, however, and US regulations uncertain.

“The engineering debate killed my career. Now, this editing debate has the potential to kill my students,” Van Eenennaam says. That would be a pity because the egg and dairy industries might end the carnage of males by controlling sex determination in animals. 

Nature runs a different story, one of bulls producing semen from another male. These surrogate fathers had their own sperm production edited out and received sperm-producing stem cells from donors.

“The goal is to spread genes for desirable traits, such as disease resistance or heat tolerance, through a population of animals in fewer generations than is possible with conventional breeding.” And also to aid efforts to conserve species for which semen storage is difficult, as Heidi Ledford explains.

Scientists are also interested in creating surrogate hens making eggs from another mother, for production or conservation goals.

Regulatory uncertainties and a lack of funding, however, are already pushing some US reproductive biologists and their edited animals abroad, into more open-minded countries such as Brazil and Argentina.