Deletion of an sRNA primes development in a multicellular bacterium

TL;DR

Deleting an sRNA called Pxr in Myxococcus xanthus changes how the bacteria develop into fruiting bodies, even when nutrients are available.

Contribution

The study identifies genes regulated by Pxr and reveals a new developmental regulator, pxrA, in myxobacteria.

Findings

Over half of the genes affected by Pxr deletion are linked to development, including critical regulators.

Pxr positively regulates genes involved in metabolic processes during growth.

The gene pxrA is identified as a Pxr target essential for multicellular development.

Abstract

Small non-coding RNAs (sRNAs) regulate gene expression of many biological processes. During growth, some myxobacteria produce an sRNA—Pxr—that blocks fruiting-body development, an aggregative multicellular process typically triggered by starvation. Deleting the pxr gene allows Myxococcus xanthus to develop despite nutrient availability, but Pxr binding targets and the genes regulated by Pxr remain unknown. Here, after showing that Pxr controls the temporal dynamics of development, we compare the transcriptomes of vegetative M. xanthus cells possessing vs. lacking pxr. Over half of the genes impacted by pxr deletion are linked to development, including known and previously undiscovered critical regulators. Pxr also positively regulates genes associated with general metabolic processes. Our study discovers phenotypic effects of Pxr regulation with ecological importance, identifies the suite of genes this sRNA controls during vegetative growth and reveals a previously unknown developmental regulator. These findings provide insights into the molecular mechanism controlling myxobacterial development.

•The sRNA Pxr influences the temporal dynamics of fruiting-body formation•Pxr regulates many metabolic genes during growth•Pxr influences developmental gene expression, including the master regulator fruA•The gene pxrA is a Pxr target critical to multicellular development

The sRNA Pxr influences the temporal dynamics of fruiting-body formation

Pxr regulates many metabolic genes during growth

Pxr influences developmental gene expression, including the master regulator fruA

The gene pxrA is a Pxr target critical to multicellular development

Biological sciences; Molecular biology; Microbiology

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