Adult bi-paternal offspring generated through direct modification of imprinted genes in mammals

https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(25)00005-0?utm_campaign=morning_rounds&utm_medium=email&_hsenc=p2ANqtz-_sb7bubYg26slaJuOqlBDdC7TUs0xUg-ZawsZ1UXwb0ntR7cgy5frimgwuId7-pIvVGshrbLRnvoslkEDaGRwBjYO3gw&_hsmi=344625380&utm_content=344625380&utm_source=hs_email The first mice with two dads have reached adulthood There’s been so much news on the “chaos” beat this week that I just had to share this: Scientists in China have successfully engineered “bi-paternal” mice (those with two male parents) that have lived until adulthood, according to a study published yesterday in Cell Stem Cell. Previous attempts have been complicated due to genetic imprinting abnormalities that lead to defects, which the authors say is a major barrier to these types of experiments. But in this study, researchers individually modified 20 key imprinting genes using multiple different methods to combat that issue. It’s cool science (that MIT Technology Review explains in more detail) but don’t forget the caveats: These are mice, not humans, or even primates. Also: Most of these embryos didn’t even make it to birth — only seven mice made it that far out of 164 embryos. Not all of those seven made it to adulthood either, and those that did often had altered growth, a shortened lifespan, and were sterile. https://www.technologyreview.com/2025/01/28/1110613/mice-with-two-dads-crispr/?utm_campaign=morning_rounds&utm_medium=email&_hsenc=p2ANqtz-_Vbfz3cakm6LrKBZZ9sBJPW1nnLwoLloxm2d0UnsvUapPlbBk5CSa9Q3KjxnvlIcbf6f3w9L5h4skIae26pT8TrWUp5g&_hsmi=344625380&utm_content=344625380&utm_source=hs_email