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Saturday, January 22, 2011

Science: Clever Amoebas Farm Their Favorite Food: Bacteria

The amoeba, Dictyostelium discoideum, is also known as a slime mould, but scientists who work with it sometimes use the more affectionate name of Dicty. Dicty spends most of its time as a single cell, oozing through the undergrowth in search of bacteria to eat. When they run out of prey, the amoebas unite to form a many-celled mobile slug. When the slug finds a good spot, it stretches upwards to form a ball at the end of a stalk. The ball is loaded with spores, which eventually blow free on the wind. When they land, they hatch into new amoebae and the life cycle begins again.

Scientists pieced together Dicty's life cycle decades ago, but it still carries surprises. Debra Brock from Rice University captured 35 wild amoebas from Virginia and Minnesota and found that a third of them carried bacteria in their slugs and spores. The bacteria hail from a number of different species, and half of these are found on Dicty's menu. When the spores land in new locations, their bacterial cargo start to multiply, which provides the amoebae with food.

For more, see Clever Amoebas Farm Their Favorite Food: Bacteria by Ed Yong, January 19, 2011 at Discover Magazine blogs.

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