Adaptive Evolution of an sRNA That Controls Myxococcus Development

摘要

Noncoding small RNA (sRNA) molecules regulate gene expression networks in all domains of life (1,2), but inferences regarding (he roles of sRNAs in adaptive evolution have been indirect Here, we show that a spontaneous adaptive mutation in the bacterium Myxococcus xanthus restored a defective social trait, multicellular fruiting body development, by deactivating a previously unknown sRNA, Pxr. We also show that Pxr acts as a pivotal regulatory checkpoint that blocks Myxococcus development until nutrients have been depleted.