Mice born in Japan from female genes

Scientista in Japan have demonstrated for the first time how mammals can reproduce without a male, leading to the birth of apparently health...

Scientista in Japan have demonstrated for the first time how mammals can reproduce without a male, leading to the birth of apparently healthy baby mice by mixing two sets of female genes inside an egg.

Experts said that it will be a long time before men are relegated to the role of bystanders in human reproduction. But the latest experiments suggest that laboratory tricks can essentially eliminate the need for fertilisation — at least in mice.

Two female mice were created in the experiments at Japan’s Tokyo University of Agriculture. One of the mice, named ‘‘Kaguya’’, has been raised to adulthood, has mated normally and has given birth to a litter of pups free of any obvious birth defects.

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The results were reported today in the journal Nature. Female-only reproduction, known as parthenogenesis, is common in the insect and reptile worlds, but there is no evidence yet that it can happen in humans or other primates. Among the practical hurdles — one of the sets of female-derived mouse genes came from a very early-stage egg not readily found in an adult human.

The experiments were designed to reveal the biology of ‘‘genetic imprinting’’, in which seemingly identical DNA sequences in male and female genes function differently depending on biochemical signals or ‘‘imprints’’ that come along with the DNA. —(NYT)