Researchers at the CAS Institute of Zoology were able to produce healthy mice with two mothers that went on to have normal offspring of their own. Mice from two fathers were also born but only survived for a couple of days. To produce healthy bimaternal mice, Qi ZHOU and colleagues used haploid embryonic stem cells (ESCs); after deleting three imprinting regions of the genome, they injected them into eggs from another female mouse. They produced 29 live mice from 210 embryos. The mice were normal, lived to adulthood, and had babies of their own. Twelve live mice with two genetic fathers were produced from haploid ESCs containing only a male parent’s DNA where seven key imprinted regions were deleted. The edited haploid ESCs were then injected, along with sperm from another male mouse, into an enucleated egg cell creating an embryo containing only genomic DNA from two male parents. These embryos were transferred along with placental material to surrogate mothers.These pups survived only 48 hours after birth.

CAS news release, October 18, 2018