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Dating phototrophic microbial lineages with reticulate gene histories

Phototrophic bacteria are among the most biogeochemically significant organisms on Earth and are physiologically related through the use of reaction centers to collect photons for energy metabolism. However, the major phototrophic lineages are not closely related to one another in bacterial phylogen...

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Autores principales: Magnabosco, C., Moore, K. R., Wolfe, J. M., Fournier, G. P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5873394/
https://www.ncbi.nlm.nih.gov/pubmed/29384268
http://dx.doi.org/10.1111/gbi.12273
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author Magnabosco, C.
Moore, K. R.
Wolfe, J. M.
Fournier, G. P.
author_facet Magnabosco, C.
Moore, K. R.
Wolfe, J. M.
Fournier, G. P.
author_sort Magnabosco, C.
collection PubMed
description Phototrophic bacteria are among the most biogeochemically significant organisms on Earth and are physiologically related through the use of reaction centers to collect photons for energy metabolism. However, the major phototrophic lineages are not closely related to one another in bacterial phylogeny, and the origins of their respective photosynthetic machinery remain obscured by time and low sequence similarity. To better understand the co‐evolution of Cyanobacteria and other ancient anoxygenic phototrophic lineages with respect to geologic time, we designed and implemented a variety of molecular clocks that use horizontal gene transfer (HGT) as additional, relative constraints. These HGT constraints improve the precision of phototroph divergence date estimates and indicate that stem green non‐sulfur bacteria are likely the oldest phototrophic lineage. Concurrently, crown Cyanobacteria age estimates ranged from 2.2 Ga to 2.7 Ga, with stem Cyanobacteria diverging ~2.8 Ga. These estimates provide a several hundred Ma window for oxygenic photosynthesis to evolve prior to the Great Oxidation Event (GOE) ~2.3 Ga. In all models, crown green sulfur bacteria diversify after the loss of the banded iron formations from the sedimentary record (~1.8 Ga) and may indicate the expansion of the lineage into a new ecological niche following the GOE. Our date estimates also provide a timeline to investigate the temporal feasibility of different photosystem HGT events between phototrophic lineages. Using this approach, we infer that stem Cyanobacteria are unlikely to be the recipient of an HGT of photosystem I proteins from green sulfur bacteria but could still have been either the HGT donor or the recipient of photosystem II proteins with green non‐sulfur bacteria, prior to the GOE. Together, these results indicate that HGT‐constrained molecular clocks are useful tools for the evaluation of various geological and evolutionary hypotheses, using the evolutionary histories of both genes and organismal lineages.
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spelling pubmed-58733942018-03-31 Dating phototrophic microbial lineages with reticulate gene histories Magnabosco, C. Moore, K. R. Wolfe, J. M. Fournier, G. P. Geobiology Original Articles Phototrophic bacteria are among the most biogeochemically significant organisms on Earth and are physiologically related through the use of reaction centers to collect photons for energy metabolism. However, the major phototrophic lineages are not closely related to one another in bacterial phylogeny, and the origins of their respective photosynthetic machinery remain obscured by time and low sequence similarity. To better understand the co‐evolution of Cyanobacteria and other ancient anoxygenic phototrophic lineages with respect to geologic time, we designed and implemented a variety of molecular clocks that use horizontal gene transfer (HGT) as additional, relative constraints. These HGT constraints improve the precision of phototroph divergence date estimates and indicate that stem green non‐sulfur bacteria are likely the oldest phototrophic lineage. Concurrently, crown Cyanobacteria age estimates ranged from 2.2 Ga to 2.7 Ga, with stem Cyanobacteria diverging ~2.8 Ga. These estimates provide a several hundred Ma window for oxygenic photosynthesis to evolve prior to the Great Oxidation Event (GOE) ~2.3 Ga. In all models, crown green sulfur bacteria diversify after the loss of the banded iron formations from the sedimentary record (~1.8 Ga) and may indicate the expansion of the lineage into a new ecological niche following the GOE. Our date estimates also provide a timeline to investigate the temporal feasibility of different photosystem HGT events between phototrophic lineages. Using this approach, we infer that stem Cyanobacteria are unlikely to be the recipient of an HGT of photosystem I proteins from green sulfur bacteria but could still have been either the HGT donor or the recipient of photosystem II proteins with green non‐sulfur bacteria, prior to the GOE. Together, these results indicate that HGT‐constrained molecular clocks are useful tools for the evaluation of various geological and evolutionary hypotheses, using the evolutionary histories of both genes and organismal lineages. John Wiley and Sons Inc. 2018-01-31 2018-03 /pmc/articles/PMC5873394/ /pubmed/29384268 http://dx.doi.org/10.1111/gbi.12273 Text en © 2018 The Authors. Geobiology Published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Articles
Magnabosco, C.
Moore, K. R.
Wolfe, J. M.
Fournier, G. P.
Dating phototrophic microbial lineages with reticulate gene histories
title Dating phototrophic microbial lineages with reticulate gene histories
title_full Dating phototrophic microbial lineages with reticulate gene histories
title_fullStr Dating phototrophic microbial lineages with reticulate gene histories
title_full_unstemmed Dating phototrophic microbial lineages with reticulate gene histories
title_short Dating phototrophic microbial lineages with reticulate gene histories
title_sort dating phototrophic microbial lineages with reticulate gene histories
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5873394/
https://www.ncbi.nlm.nih.gov/pubmed/29384268
http://dx.doi.org/10.1111/gbi.12273
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