Lectins modulate the microbiota of social amoebae

Abstract

Sticky bacteria tolerated as future food Dictyostelium discoideum amoebae consume bacteria until the supply is exhausted. Then the amoeba cells clump together into a “slug” and initiate a complex multicellular reproductive phase. Specialized cells within aggregates rid the slug of any extracellular bacteria. However, some strains of amoeba tolerate live, intracellular bacteria. Dinh et al. discovered that these carrier strains bear surface lectins that bind Klebsiella bacteria, promote cell entry, and prevent the bacteria from being immediately digested. These bacteria then provide a future food source. Moreover, the internalized bacteria transfer DNA into the amoeba nucleus, resulting in transient genetic transformation. Science , this issue p. 402