Growing animals like navel oranges
Mice created without fathers
By Paul Rincon
BBC News Online science staff
Scientists have created two female mice without fertilising the eggs they grew from, the journal Nature says.
The eggs had two sets of chromosomes from two female mice, rather than one from the mother and one from the father as in a fertilised embryo.
The phenomenon, called parthenogenesis, never occurs naturally in mammals.
Some researchers say the procedures may be applied to stem cell research, but the scientists who carried out the work say it would not yet work in humans.
Mammal difference
Tomohiro Kono and colleagues switched off a key gene in the donor eggs which affected imprinting - a barrier to parthenogenesis in mammals.
"Insects can reproduce by parthenogenesis. Even chickens can be made to reproduce by parthenogenesis. I wanted to find out why mammals are different," Dr Kono of Tokyo University of Agriculture, Japan, told BBC News Online.
Let me take this opportunity to say the outlook current in most humans is such that I really hope a lot of what's under development takes a long, long, long time…time on an evolutionary scale, perhaps…to come to fruition.