Genes Not From Germs, Researchers Report

Humans did not acquire genes directly from bacteria as previously thought, American researchers reported in the June 21 issue of Nature. One of the big surprises of the sequencing of the human genetic code, apart from the relatively small number of genes we have and how little we differ from other organisms, was that 223 of our genes seemed to have come from bacteria.

But researchers at pharmaceutical giant GlaxoSmithKline’s research center in Pennsylvania have “debugged” the theory. They say new research shows that those 223 genes did not transfer directly to humans from bacteria but came from common ancestors hundreds of millions of years ago. “All the genes that we share with the bacteria can be traced back to much older organisms,” said James Brown, an evolutionary biologist at the company.

Brown believes the finding is important because it shows it is unlikely that infectious bacteria or genetically modified organisms (GMOs) could transfer genes to humans, which should ease some fears about GMOs.

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Compiled by Times medical writer Thomas H. Maugh II