Coevolving Plasmids Drive Gene Flow and Genome Plasticity in Host-Associated Intracellular Bacteria

Author(s)
Stephan Köstlbacher, Astrid Horn, Tamara Halter, Daryl Domman, Matthias Horn
Abstract

Plasmids are important in microbial evolution and adaptation to new environments. Yet, carrying a plasmid can be costly, and long-term association of plasmids with their hosts is poorly understood. Here, we provide evidence that the Chlamydiae, a phylum of strictly host-associated intracellular bacteria, have coevolved with their plasmids since their last common ancestor. Current chlamydial plasmids are amalgamations of at least one ancestral plasmid and a bacteriophage. We show that the majority of plasmid genes are also found on chromosomes of extant chlamydiae. The most conserved plasmid gene families are predominantly vertically inherited, while accessory plasmid gene families show significantly increased mobility. We reconstructed the evolutionary history of plasmid gene content of an entire bacterial phylum over a period of around one billion years. Frequent horizontal gene transfer and chromosomal integration events illustrate the pronounced impact of coevolution with these extrachromosomal elements on bacterial genome dynamics in host-dependent microbes.

Organisation(s)
Department of Microbiology and Ecosystem Science
External organisation(s)
University of Cambridge, University of New Mexico
Journal
Current Biology
Volume
31
Pages
346-357
No. of pages
15
ISSN
0960-9822
DOI
https://doi.org/10.1016/j.cub.2020.10.030
Publication date
11-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
106012 Evolutionary research, 106014 Genomics, 106022 Microbiology
Keywords
ASJC Scopus subject areas
General Agricultural and Biological Sciences, General Biochemistry,Genetics and Molecular Biology, General Neuroscience
Portal url
https://ucrisportal.univie.ac.at/en/publications/3e57de2e-760e-49ab-9033-2027d46b0e4a