The ability to identify self and non-self enables cells in more sophisticated animals to ward off invading infections, but it is critical to even simpler organisms such as the social amoebae Dictyostelium discoideum.
Dictyostelium exists as a single cell when times are good, but when starved, the cells aggregate and become multi-cellular fruiting bodies with a dead stalk and live spores that allow the cells to survive and pass on genes. When the social amoeba aggregates, it prefers to do so with "kin," the cells that are genetically most like it.
Now researchers at Baylor College of Medicine have identified the genetic "lock and key" that enable the amoeba to tell kin from non-kin. A report on their work appears online in Science Express).
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