The mice with two mothers went on to produce offspring of their own

Chinese scientists have created healthy baby mice with two mothers and no father, pushing back the barriers to same-sex reproduction in humans.

Mice that had two fathers were also born but survived for only a couple of days. The work hinged on using genetic editing techniques to tackle “genomic imprinting” — a mechanism in mammals that means DNA must usually be present from a mother and father to create healthy offspring.

Experts said that the concept was intriguing for its possible application to human reproduction. They warned, however, of formidable ethical concerns and technical challenges.

Across much of nature it is possible to create animals using only genetic material from females but in mammals a sperm must usually meet an egg. Each brings with it