Same-sex mice have babies

Baby mice have been made with two mums and no dad, say researchers at the Chinese Academy of Sciences.
It took a substantial feat of genetic engineering to break the rules of reproduction.
The scientists said the “bimaternal” (two mammas) animals were healthy and went on to have pups of their own.
But there was bad news on the all-male front. Mice with double-dads were attempted, but died within days of being born.
The researchers were trying to answer fundamental questions about why we have sex.
Mammals, including us, can make babies only through sexual reproduction – aka you need an egg from mum and a sperm from dad.
But the rest of the natural world doesn’t play by the same rules; some female fish, reptiles, amphibians and birds can go it alone.
Welcome to the bizarre world of virgin births known officially as parthenogenesis.
The aim of the Chinese researchers was to work out which rules of reproduction they needed to break to make baby mice from same-sex parents.
That in turn helps understand why the rules are so important.
“It’s an interesting paper… they’re trying to work out what you would have to do to turn us into turkeys,” said Prof Robin Lovell-Badge at the Francis Crick Institute.
In short, with a lot of cutting-edge science.
It was easier with double mums. The researchers took an egg from one mouse and a special type of cell – a haploid embryonic stem cell – from another.
Both contained only half the required genetic instructions or DNA, but just bringing them together wasn’t enough.
The researchers had to use a technology called gene editing to delete three sets of genetic instructions to make them compatible (more on that later).
The double-dad approach was slightly more complicated.
It took a sperm, a male haploid embryonic stem cell, an egg that had all of its own genetic information removed and the deletion of seven genes to make it all work.