Spatially segregated transcription and translation in cells of the endomembrane-containing bacterium Gemmata obscuriglobus

Eukaryotic (plant and animal) cells possess a nuclear membrane that separates the two stages of gene expression (transcription and translation), whereas prokaryotic (bacteria and archaea) cells lack the nuclear membrane barrier to colocated transcription and translation. However, cells of the bacterium Gemmata obscuriglobus possess extensive intracellular membranes, resulting in superficially eukaryote-like cellular complexity. We have found that a substantial amount of G. obscuriglobus translation is uncoupled from transcription, broadening our understanding of the spatial organization of bacterial gene expression, which currently is based entirely on a handful of model species. This broader understanding provides a useful background for consideration of the evolutionary development of eukaryotic cellular complexity and how it led to decoupled processes of gene expression in eukaryotes.