The genes in mitochondria, which are the powerhouses in human cells, can cause fatal inherited disease. But replacing the bad genes may cause other health problems.
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In 2010, scientists plopped the genetic material of one Mycoplasma bacterium into another type to create the self-replicating cells shown above. Six years later, they've come out with an even simpler synthetic organism that has fewer genes.
Thomas Deerinck, NCMIR/Science Source
An image of researchers at Oregon Health & Science University removing the nucleus from the mother's cell before it's inserted into the donor's egg cell.
Courtesty of Oregon Health & Science University
Watson, now 84, says sequencing helped explain his past sensitivity to certain drugs. But he didn't want to know everything his sequenced genome revealed about his health future.
Courtesy of Cold Spring Harbor Laboratory