1. Intragenic DNA inversions expand bacterial coding capacity
- Author
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Rachael B. Chanin, Patrick T. West, Ryan M. Park, Jakob Wirbel, Gabriella Z. M. Green, Arjun M. Miklos, Matthew O. Gill, Angela S. Hickey, Erin F. Brooks, and Ami S. Bhatt
- Subjects
Article - Abstract
Bacterial populations that originate from a single bacterium are not strictly clonal. Often they contain subgroups that have distinct phenotypes. One way that bacteria generate this heterogeneity is through phase variation: enzyme-mediated, reversible inversion of specific intergenic regions of genomic DNA. These DNA inversions can flip the orientation of promoters within otherwise isogenic populations, impacting fitness and survival. We developed and applied bioinformatic approaches that enabled the discovery of thousands of previously undescribed phase-variable regions in prokaryotes using long-read datasets. We identified ‘intragenic invertons’, a surprising new class of invertible elements found entirely within genes, across the prokaryotic tree of life. Intragenic invertons allow a single gene to encode two or more versions of a protein by flipping a DNA sequence within the gene, thereby increasing coding capacity without increasing genome size. We experimentally characterize specific intragenic invertons in the gut commensalBacteroides thetaiotaomicron, presenting a ‘roadmap’ for investigating this gene-diversifying phenomenon.One-Sentence SummaryIntragenic DNA inversions, identified using long-read sequencing datasets, are found across the prokaryotic tree of life.
- Published
- 2023