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bioRxiv · 10.1101/2020.05.06.055103

Phage recombination drives evolution of spore-forming Bacilli

Dragos, A.·B, P.·Hasan, Z.·Lenz-Strube, M.·Kempen, P. J.·Maroti, G.·Kaspar, C.·Bischofs, I. B.·Kovacs, A. T.
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Abstract

Phages are the main source of within-species bacterial diversity and drivers of horizontal gene transfer, but we know little about the mechanisms that drive genetic diversity of these mobile genetic elements (MGEs). Recently, we showed that a sporulation selection regime promotes evolutionary changes within SP{beta} prophage of Bacillus subtilis, leading to direct antagonistic interactions within the population. Herein, we reveal that under a sporulation selection regime, SP{beta} recombines with low copy number phi3Ts phage DNA present within the B. subtilis population. Recombination results in a new prophage occupying a different integration site, as well as the spontaneous release of virulent phage hybrids. Analysis of Bacillus sp. strains suggests that SP{beta} and phi3T belong to a distinct cluster of unusually large phages inserted into sporulation-related genes that are equipped with a spore-related genetic arsenal. Comparison of Bacillus sp. genomes indicates that similar diversification of SP{beta}-like phages takes place in nature. Our work is a stepping stone toward empirical studies on phage evolution, and understanding the eco-evolutionary relationships between bacteria and their phages. By capturing the first steps of new phage evolution, we reveal striking relationship between survival strategy of bacteria and evolution of their phages.

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Dragos, A., B, P., Hasan, Z., Lenz-Strube, M., Kempen, P. J., Maroti, G., Kaspar, C., Bischofs, I. B., Kovacs, A. T.. 2020-05-07. Phage recombination drives evolution of spore-forming Bacilli. https://doi.org/10.1101/2020.05.06.055103

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