Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation

<p>Abstract</p> <p>Background</p> <p>One mechanism to account for robustness against gene knockouts or knockdowns is through buffering by gene duplicates, but the extent and general correlates of this process in organisms is still a matter of debate. To reveal general t...

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Main Authors: Vogel Christine, Marcotte Edward M, Hannay Kevin
Format: Article
Language:English
Published: BMC 2008-12-01
Series:BMC Genomics
Online Access:http://www.biomedcentral.com/1471-2164/9/609
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author Vogel Christine
Marcotte Edward M
Hannay Kevin
author_facet Vogel Christine
Marcotte Edward M
Hannay Kevin
author_sort Vogel Christine
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>One mechanism to account for robustness against gene knockouts or knockdowns is through buffering by gene duplicates, but the extent and general correlates of this process in organisms is still a matter of debate. To reveal general trends of this process, we provide a comprehensive comparison of gene essentiality, duplication and buffering by duplicates across seven bacteria (<it>Mycoplasma genitalium, Bacillus subtilis, Helicobacter pylori, Haemophilus influenzae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Escherichia coli</it>), and four eukaryotes (<it>Saccharomyces cerevisiae </it>(yeast), <it>Caenorhabditis elegans </it>(worm), <it>Drosophila melanogaster </it>(fly), <it>Mus musculus </it>(mouse)).</p> <p>Results</p> <p>In nine of the eleven organisms, duplicates significantly increase chances of survival upon gene deletion (P-value ≤ 0.05), but only by up to 13%. Given that duplicates make up to 80% of eukaryotic genomes, the small contribution is surprising and points to dominant roles of other buffering processes, such as alternative metabolic pathways. The buffering capacity of duplicates appears to be independent of the degree of gene essentiality and tends to be higher for genes with high expression levels. For example, buffering capacity increases to 23% amongst highly expressed genes in <it>E. coli</it>. Sequence similarity and the number of duplicates per gene are weak predictors of the duplicate's buffering capacity. In a case study we show that buffering gene duplicates in yeast and worm are somewhat more similar in their functions than non-buffering duplicates and have increased transcriptional and translational activity.</p> <p>Conclusion</p> <p>In sum, the extent of gene essentiality and buffering by duplicates is not conserved across organisms and does not correlate with the organisms' apparent complexity. This heterogeneity goes beyond what would be expected from differences in experimental approaches alone. Buffering by duplicates contributes to robustness in several organisms, but to a small extent – and the relatively large amount of buffering by duplicates observed in yeast and worm may be largely specific to these organisms. Thus, the only common factor of buffering by duplicates between different organisms may be the by-product of duplicate retention due to demands of high dosage.</p>
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spelling doaj.art-2167602d9f1a41e3af490ae8568cb09c2022-12-22T01:20:00ZengBMCBMC Genomics1471-21642008-12-019160910.1186/1471-2164-9-609Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservationVogel ChristineMarcotte Edward MHannay Kevin<p>Abstract</p> <p>Background</p> <p>One mechanism to account for robustness against gene knockouts or knockdowns is through buffering by gene duplicates, but the extent and general correlates of this process in organisms is still a matter of debate. To reveal general trends of this process, we provide a comprehensive comparison of gene essentiality, duplication and buffering by duplicates across seven bacteria (<it>Mycoplasma genitalium, Bacillus subtilis, Helicobacter pylori, Haemophilus influenzae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Escherichia coli</it>), and four eukaryotes (<it>Saccharomyces cerevisiae </it>(yeast), <it>Caenorhabditis elegans </it>(worm), <it>Drosophila melanogaster </it>(fly), <it>Mus musculus </it>(mouse)).</p> <p>Results</p> <p>In nine of the eleven organisms, duplicates significantly increase chances of survival upon gene deletion (P-value ≤ 0.05), but only by up to 13%. Given that duplicates make up to 80% of eukaryotic genomes, the small contribution is surprising and points to dominant roles of other buffering processes, such as alternative metabolic pathways. The buffering capacity of duplicates appears to be independent of the degree of gene essentiality and tends to be higher for genes with high expression levels. For example, buffering capacity increases to 23% amongst highly expressed genes in <it>E. coli</it>. Sequence similarity and the number of duplicates per gene are weak predictors of the duplicate's buffering capacity. In a case study we show that buffering gene duplicates in yeast and worm are somewhat more similar in their functions than non-buffering duplicates and have increased transcriptional and translational activity.</p> <p>Conclusion</p> <p>In sum, the extent of gene essentiality and buffering by duplicates is not conserved across organisms and does not correlate with the organisms' apparent complexity. This heterogeneity goes beyond what would be expected from differences in experimental approaches alone. Buffering by duplicates contributes to robustness in several organisms, but to a small extent – and the relatively large amount of buffering by duplicates observed in yeast and worm may be largely specific to these organisms. Thus, the only common factor of buffering by duplicates between different organisms may be the by-product of duplicate retention due to demands of high dosage.</p>http://www.biomedcentral.com/1471-2164/9/609
spellingShingle Vogel Christine
Marcotte Edward M
Hannay Kevin
Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
BMC Genomics
title Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
title_full Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
title_fullStr Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
title_full_unstemmed Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
title_short Buffering by gene duplicates: an analysis of molecular correlates and evolutionary conservation
title_sort buffering by gene duplicates an analysis of molecular correlates and evolutionary conservation
url http://www.biomedcentral.com/1471-2164/9/609
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