Genetic Pickup: Did animals get brain genes from bacteria?
By John Travis
Reviving a controversy about whether animals have acquired key genes from bacteria, a study suggests that microbes have provided genes that now play vital roles in brain-cell signaling and other forms of cell-to-cell communication. The genes implicated encode enzymes required for the metabolism and synthesis of crucial brain chemicals, including dopamine, serotonin, melatonin, and histamine.
“These enzymes did not evolve [in animals]. They were picked up, as a shortcut,” contends David C. Klein of the National Institute of Child Health and Human Development in Bethesda, Md.