The only way they'll know is by injecting some of them into mouse eggs. (discovermagazine.com)
In the study, 72 percent of nearly 3,000 mouse egg cells survived. (scientificamerican.com)
To do so, a team led by neuroscientist David Holtzman of Washington University in St. Louis injected genes for human apoE3 or apoE4, which is about a third as common, into fertilized mouse eggs. (sciencemag.org)