The Future is CRISPR

Alison Van Eenennaam, a professor at the University of California, Davis, has a few very pregnant patients to look after this fall and into the new year. These patients require some extra care, as they’re carrying experimental fetuses. 

Van Eenennaam, a professor of animal biotechnology, implanted embryos this spring in a herd of cattle, which carry the SRY gene. The fetuses—all female—will develop male characteristics, growing beefier and faster than females without the gene, something that would benefit cattle producers, says Van Eenennaam, who runs the Animal Genomics and Biotechnology Laboratory at UC Davis. 

The embryos were created from the semen of a bull named Cosmo. The SRY gene he passed on wasn’t developed through classic selective breeding, however, but a technology seemingly appropriated from science fiction—CRISPR/Ca9. The technology accelerates trait development by facilitating the precise deletion, insertion or modification of genes. It can also “turn off” or inactivate genes that make animals susceptible to some diseases, says Van Eenennaam. By inserting the SRY gene into chromosome 17 when Cosmo was an early-stage embryo, the gene became something he now passes on to all offspring, no matter the sex. 

The technology received the Nobel Prize in Chemistry 2020, igniting a flurry of research as scientists explored its potential to change plant and animal DNA. With a growing global population of eight billion and the demand for animal protein soaring, new technologies are needed to make agriculture more efficient while reducing its enormous environmental impact. CRISPR promises a genetic revolution, with advocates hopeful that it can address disease prevention, food security and a reduction of methane, the