An RNA-centric view on gut Bacteroidetes.

Bacteria employ noncoding RNAs to maintain cellular physiology, adapt global gene expression to fluctuating environments, sense nutrients, coordinate their interaction with companion microbes and host cells, and protect themselves against bacteriophages. While bacterial RNA research has made fundamental contributions to biomedicine and biotechnology, the bulk of our knowledge of RNA biology stems from the study of a handful of aerobic model species. In comparison, RNA research is lagging in many medically relevant obligate anaerobic species, in particular the numerous commensal bacteria comprising our gut microbiota. This review presents a guide to RNA-based regulatory mechanisms in the phylum Bacteroidetes, focusing on the most abundant bacterial genus in the human gut, spp. This includes recent case reports on riboswitches, an mRNA leader, - and -encoded small RNAs (sRNAs) in spp., and a survey of CRISPR-Cas systems across Bacteroidetes. Recent work from our laboratory now suggests the existence of hundreds of noncoding RNA candidates in , the emerging model organism for functional microbiota research. Based on these collective observations, we predict mechanistic and functional commonalities and differences between sRNAs and those of other model bacteria, and outline open questions and tools needed to boost Bacteroidetes RNA research.

© 2020 Daniel Ryan et al., published by De Gruyter, Berlin/Boston.