Transcriptional changes when Myxococcus xanthus preys on Escherichia coli suggest myxobacterial predators are constitutively toxic but regulate their feeding

Abstract

Predation is a fundamental ecological process, but within microbial ecosystems the mechanisms of predation remain poorly understood for most predators. We investigated transcriptome changes associated with the predation of Escherichia coli by the ‘wolf-pack’ myxobacterial predator Myxococcus xanthus using mRNA sequencing. While large-scale changes in gene expression were observed in the prey organism, exposure to prey altered the expression of only a small number of genes in the predator (osmoregulation genes). It seems that predator genes required for prey killing are expressed constitutively, and the predator instead responds to the death throes of the prey – more reminiscent of a web-building spider than a wolf-pack. This study provides a framework for further investigations into the gene regulatory changes associated with microbial predation, which will inform future efforts to exploit the antimicrobial activity of predators in the control of problem prey microbes.