Cargando…

Selective advantages favour high genomic AT-contents in intracellular elements

Extrachromosomal genetic elements such as bacterial endosymbionts and plasmids generally exhibit AT-contents that are increased relative to their hosts’ DNA. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes such as a mutational bias towards increased A+T....

Descripción completa

Detalles Bibliográficos
Autores principales: Dietel, Anne-Kathrin, Merker, Holger, Kaltenpoth, Martin, Kost, Christian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519830/
https://www.ncbi.nlm.nih.gov/pubmed/31034469
http://dx.doi.org/10.1371/journal.pgen.1007778
_version_ 1783418673084497920
author Dietel, Anne-Kathrin
Merker, Holger
Kaltenpoth, Martin
Kost, Christian
author_facet Dietel, Anne-Kathrin
Merker, Holger
Kaltenpoth, Martin
Kost, Christian
author_sort Dietel, Anne-Kathrin
collection PubMed
description Extrachromosomal genetic elements such as bacterial endosymbionts and plasmids generally exhibit AT-contents that are increased relative to their hosts’ DNA. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes such as a mutational bias towards increased A+T. Here we show experimentally that an increased AT-content of host-dependent elements can be selectively favoured. Manipulating the nucleotide composition of bacterial cells by introducing A+T-rich or G+C-rich plasmids, we demonstrate that cells containing GC-rich plasmids are less fit than cells containing AT-rich plasmids. Moreover, the cost of GC-rich elements could be compensated by providing precursors of G+C, but not of A+T, thus linking the observed fitness effects to the cytoplasmic availability of nucleotides. Accordingly, introducing AT-rich and GC-rich plasmids into other bacterial species with different genomic GC-contents revealed that the costs of G+C-rich plasmids decreased with an increasing GC-content of their host’s genomic DNA. Taken together, our work identifies selection as a strong evolutionary force that drives the genomes of intracellular genetic elements toward higher A+T contents.
format Online
Article
Text
id pubmed-6519830
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-65198302019-05-31 Selective advantages favour high genomic AT-contents in intracellular elements Dietel, Anne-Kathrin Merker, Holger Kaltenpoth, Martin Kost, Christian PLoS Genet Research Article Extrachromosomal genetic elements such as bacterial endosymbionts and plasmids generally exhibit AT-contents that are increased relative to their hosts’ DNA. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes such as a mutational bias towards increased A+T. Here we show experimentally that an increased AT-content of host-dependent elements can be selectively favoured. Manipulating the nucleotide composition of bacterial cells by introducing A+T-rich or G+C-rich plasmids, we demonstrate that cells containing GC-rich plasmids are less fit than cells containing AT-rich plasmids. Moreover, the cost of GC-rich elements could be compensated by providing precursors of G+C, but not of A+T, thus linking the observed fitness effects to the cytoplasmic availability of nucleotides. Accordingly, introducing AT-rich and GC-rich plasmids into other bacterial species with different genomic GC-contents revealed that the costs of G+C-rich plasmids decreased with an increasing GC-content of their host’s genomic DNA. Taken together, our work identifies selection as a strong evolutionary force that drives the genomes of intracellular genetic elements toward higher A+T contents. Public Library of Science 2019-04-29 /pmc/articles/PMC6519830/ /pubmed/31034469 http://dx.doi.org/10.1371/journal.pgen.1007778 Text en © 2019 Dietel et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Dietel, Anne-Kathrin
Merker, Holger
Kaltenpoth, Martin
Kost, Christian
Selective advantages favour high genomic AT-contents in intracellular elements
title Selective advantages favour high genomic AT-contents in intracellular elements
title_full Selective advantages favour high genomic AT-contents in intracellular elements
title_fullStr Selective advantages favour high genomic AT-contents in intracellular elements
title_full_unstemmed Selective advantages favour high genomic AT-contents in intracellular elements
title_short Selective advantages favour high genomic AT-contents in intracellular elements
title_sort selective advantages favour high genomic at-contents in intracellular elements
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519830/
https://www.ncbi.nlm.nih.gov/pubmed/31034469
http://dx.doi.org/10.1371/journal.pgen.1007778
work_keys_str_mv AT dietelannekathrin selectiveadvantagesfavourhighgenomicatcontentsinintracellularelements
AT merkerholger selectiveadvantagesfavourhighgenomicatcontentsinintracellularelements
AT kaltenpothmartin selectiveadvantagesfavourhighgenomicatcontentsinintracellularelements
AT kostchristian selectiveadvantagesfavourhighgenomicatcontentsinintracellularelements