Nobel laureate David Baltimore of Caltech speaks to reporters at the National Academy of Sciences international summit on human gene editing, on Tuesday in Washington, D.C. Hundreds of scientists and ethicists from around the world debating how to deal with technology that makes it easy to edit the human genetic code.
Along with sperm, the in vitro procedure adds fresh mitochondria extracted from less mature cells in the same woman's ovaries. The hope is to revitalize older eggs with these extra "batteries." But the FDA still wants proof that the technique works and is safe.
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The size of the brain of a chimpanzee (right) is considerably smaller than that of a human brain. Probably multiple stretches of DNA help determine that, geneticists say.
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Being able to insert the two man-made letters into DNA, alongside the usual four-letter alphabet, could teach old cells new tricks and lead to better drugs, researchers say.
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Botulism bacteria, or Clostridium botulinum, grow in poorly preserved canned foods, especially meat and fish. The microbe's toxin could be lethal as a bioweapon.
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