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. 2024 Oct 25;386(6720):414-420.
doi: 10.1126/science.adj9504. Epub 2024 Oct 24.

A ubiquitous mobile genetic element changes the antagonistic weaponry of a human gut symbiont

Madeline L Sheahan  1   2 , Katia Flores  1   2 , Michael J Coyne  1   2   3 , Leonor García-Bayona  1   2   3 , Maria Chatzidaki-Livanis  3 , Andrea Q Holst  3   4 , Rita C Smith  1 , Anitha Sundararajan  1 , Blanca Barquera  5   6   7 , Laurie E Comstock  1   2   3
Affiliations

A ubiquitous mobile genetic element changes the antagonistic weaponry of a human gut symbiont

Madeline L Sheahan et al. Science. .

Abstract

DNA transfer is ubiquitous in the human gut microbiota, especially among species of the order Bacteroidales. In silico analyses have revealed hundreds of mobile genetic elements shared between these species, yet little is known about the phenotypes they encode, their effects on fitness, or pleiotropic consequences for the recipient's genome. In this work, we show that acquisition of a ubiquitous integrative conjugative element (ICE) encoding a type VI secretion system (T6SS) shuts down the native T6SS of Bacteroides fragilis. Despite inactivating this T6SS, ICE acquisition increases the fitness of the B. fragilis transconjugant over its progenitor by arming it with the new T6SS. DNA transfer causes the strain to change allegiances so that it no longer targets ecosystem members with the same element yet is armed for communal defense.

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Conflict of interest statement

Competing interests: Authors declare that they have no competing interests.

Update of

References

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