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Garushyants SK, Sane M, Selifanova MV, Agashe D, Bazykin GA, Gelfand MS. Mutational Signatures in Wild Type Escherichia coli Strains Reveal Predominance of DNA Polymerase Errors. Genome Biol Evol 2024; 16:evae035. [PMID: 38401265 PMCID: PMC10995721 DOI: 10.1093/gbe/evae035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 02/26/2024] Open
Abstract
While mutational processes operating in the Escherichia coli genome have been revealed by multiple laboratory experiments, the contribution of these processes to accumulation of bacterial polymorphism and evolution in natural environments is unknown. To address this question, we reconstruct signatures of distinct mutational processes from experimental data on E. coli hypermutators, and ask how these processes contribute to differences between naturally occurring E. coli strains. We show that both mutations accumulated in the course of evolution of wild-type strains in nature and in the lab-grown nonmutator laboratory strains are explained predominantly by the low fidelity of DNA polymerases II and III. By contrast, contributions specific to disruption of DNA repair systems cannot be detected, suggesting that temporary accelerations of mutagenesis associated with such disruptions are unimportant for within-species evolution. These observations demonstrate that accumulation of diversity in bacterial strains in nature is predominantly associated with errors of DNA polymerases.
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Affiliation(s)
- Sofya K Garushyants
- A.A. Kharkevich Institute for Information Transmission Problems, RAS, Moscow, Russia
| | - Mrudula Sane
- National Centre for Biological Sciences, Bengaluru, India
| | - Maria V Selifanova
- Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Deepa Agashe
- National Centre for Biological Sciences, Bengaluru, India
| | - Georgii A Bazykin
- A.A. Kharkevich Institute for Information Transmission Problems, RAS, Moscow, Russia
| | - Mikhail S Gelfand
- A.A. Kharkevich Institute for Information Transmission Problems, RAS, Moscow, Russia
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology (Skoltech), Moscow, Russia
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2
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Kruchinin AA, Kamzeeva PN, Zharkov DO, Aralov AV, Makarova AV. 8-Oxoadenine: A «New» Player of the Oxidative Stress in Mammals? Int J Mol Sci 2024; 25:1342. [PMID: 38279342 PMCID: PMC10816367 DOI: 10.3390/ijms25021342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/13/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024] Open
Abstract
Numerous studies have shown that oxidative modifications of guanine (7,8-dihydro-8-oxoguanine, 8-oxoG) can affect cellular functions. 7,8-Dihydro-8-oxoadenine (8-oxoA) is another abundant paradigmatic ambiguous nucleobase but findings reported on the mutagenicity of 8-oxoA in bacterial and eukaryotic cells are incomplete and contradictory. Although several genotoxic studies have demonstrated the mutagenic potential of 8-oxoA in eukaryotic cells, very little biochemical and bioinformatics data about the mechanism of 8-oxoA-induced mutagenesis are available. In this review, we discuss dual coding properties of 8-oxoA, summarize historical and recent genotoxicity and biochemical studies, and address the main protective cellular mechanisms of response to 8-oxoA. We also discuss the available structural data for 8-oxoA bypass by different DNA polymerases as well as the mechanisms of 8-oxoA recognition by DNA repair enzymes.
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Affiliation(s)
- Alexander A. Kruchinin
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- National Research Center, Kurchatov Institute, Kurchatov sq. 2, 123182 Moscow, Russia
| | - Polina N. Kamzeeva
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
| | - Dmitry O. Zharkov
- Department of Natural Sciences, Novosibirsk State University, 1 Pirogova St., 630090 Novosibirsk, Russia;
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Andrey V. Aralov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
| | - Alena V. Makarova
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- National Research Center, Kurchatov Institute, Kurchatov sq. 2, 123182 Moscow, Russia
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3
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Horton JS, Taylor TB. Mutation bias and adaptation in bacteria. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37943288 DOI: 10.1099/mic.0.001404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
Genetic mutation, which provides the raw material for evolutionary adaptation, is largely a stochastic force. However, there is ample evidence showing that mutations can also exhibit strong biases, with some mutation types and certain genomic positions mutating more often than others. It is becoming increasingly clear that mutational bias can play a role in determining adaptive outcomes in bacteria in both the laboratory and the clinic. As such, understanding the causes and consequences of mutation bias can help microbiologists to anticipate and predict adaptive outcomes. In this review, we provide an overview of the mechanisms and features of the bacterial genome that cause mutational biases to occur. We then describe the environmental triggers that drive these mechanisms to be more potent and outline the adaptive scenarios where mutation bias can synergize with natural selection to define evolutionary outcomes. We conclude by describing how understanding mutagenic genomic features can help microbiologists predict areas sensitive to mutational bias, and finish by outlining future work that will help us achieve more accurate evolutionary forecasts.
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Affiliation(s)
- James S Horton
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, BA2 7AY, UK
| | - Tiffany B Taylor
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, BA2 7AY, UK
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Schroeder JW, Hurto RL, Randall JR, Wozniak KJ, Timko TA, Nye TM, Wang JD, Freddolino PL, Simmons LA. RNase H genes cause distinct impacts on RNA:DNA hybrid formation and mutagenesis genome wide. SCIENCE ADVANCES 2023; 9:eadi5945. [PMID: 37494439 PMCID: PMC10371020 DOI: 10.1126/sciadv.adi5945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/23/2023] [Indexed: 07/28/2023]
Abstract
RNA:DNA hybrids compromise replication fork progression and genome integrity in all cells. The overall impacts of naturally occurring RNA:DNA hybrids on genome integrity, and the relative contributions of ribonucleases H to mitigating the negative effects of hybrids, remain unknown. Here, we investigate the contributions of RNases HII (RnhB) and HIII (RnhC) to hybrid removal, DNA replication, and mutagenesis genome wide. Deletion of either rnhB or rnhC triggers RNA:DNA hybrid accumulation but with distinct patterns of mutagenesis and hybrid accumulation. Across all cells, hybrids accumulate strongly in noncoding RNAs and 5'-UTRs of coding sequences. For ΔrnhB, hybrids accumulate preferentially in untranslated regions and early in coding sequences. We show that hybrid accumulation is particularly sensitive to gene expression in ΔrnhC cells. DNA replication in ΔrnhC cells is disrupted, leading to transversions and structural variation. Our results resolve the outstanding question of how hybrids in native genomic contexts cause mutagenesis and shape genome organization.
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Affiliation(s)
- Jeremy W. Schroeder
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Rebecca L. Hurto
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Justin R. Randall
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Katherine J. Wozniak
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Room 743E, Houston, TX 77030, USA
| | - Taylor A. Timko
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Taylor M. Nye
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jue D. Wang
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI 53706, USA
| | - Peter L. Freddolino
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Lyle A. Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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Goodall DJ, Warecka D, Hawkins M, Rudolph CJ. Interplay between chromosomal architecture and termination of DNA replication in bacteria. Front Microbiol 2023; 14:1180848. [PMID: 37434703 PMCID: PMC10331603 DOI: 10.3389/fmicb.2023.1180848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023] Open
Abstract
Faithful transmission of the genome from one generation to the next is key to life in all cellular organisms. In the majority of bacteria, the genome is comprised of a single circular chromosome that is normally replicated from a single origin, though additional genetic information may be encoded within much smaller extrachromosomal elements called plasmids. By contrast, the genome of a eukaryote is distributed across multiple linear chromosomes, each of which is replicated from multiple origins. The genomes of archaeal species are circular, but are predominantly replicated from multiple origins. In all three cases, replication is bidirectional and terminates when converging replication fork complexes merge and 'fuse' as replication of the chromosomal DNA is completed. While the mechanics of replication initiation are quite well understood, exactly what happens during termination is far from clear, although studies in bacterial and eukaryotic models over recent years have started to provide some insight. Bacterial models with a circular chromosome and a single bidirectional origin offer the distinct advantage that there is normally just one fusion event between two replication fork complexes as synthesis terminates. Moreover, whereas termination of replication appears to happen in many bacteria wherever forks happen to meet, termination in some bacterial species, including the well-studied bacteria Escherichia coli and Bacillus subtilis, is more restrictive and confined to a 'replication fork trap' region, making termination even more tractable. This region is defined by multiple genomic terminator (ter) sites, which, if bound by specific terminator proteins, form unidirectional fork barriers. In this review we discuss a range of experimental results highlighting how the fork fusion process can trigger significant pathologies that interfere with the successful conclusion of DNA replication, how these pathologies might be resolved in bacteria without a fork trap system and how the acquisition of a fork trap might have provided an alternative and cleaner solution, thus explaining why in bacterial species that have acquired a fork trap system, this system is remarkably well maintained. Finally, we consider how eukaryotic cells can cope with a much-increased number of termination events.
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Affiliation(s)
- Daniel J. Goodall
- Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | | | | | - Christian J. Rudolph
- Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, United Kingdom
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6
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Schroeder JW, Hurto RL, Randall JR, Wozniak KJ, Timko TA, Nye TM, Wang JD, Freddolino PL, Simmons LA. RNase H genes cause distinct impacts on RNA:DNA hybrid formation and mutagenesis genome-wide. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539860. [PMID: 37214986 PMCID: PMC10197577 DOI: 10.1101/2023.05.08.539860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
RNA:DNA hybrids such as R-loops affect genome integrity and DNA replication fork progression. The overall impacts of naturally occurring RNA:DNA hybrids on genome integrity, and the relative contributions of ribonucleases H to mitigating the negative effects of hybrids, remain unknown. Here, we investigate the contributions of RNases HII (RnhB) and HIII (RnhC) to hybrid removal, DNA replication, and mutagenesis genome-wide. Deletion of either rnhB or rnhC triggers RNA:DNA hybrid accumulation, but with distinct patterns of mutagenesis and hybrid accumulation. Across all cells, hybrids accumulate most strongly in non-coding RNAs and 5'-UTRs of coding sequences. For Δ rnhB , hybrids accumulate preferentially in untranslated regions and early in coding sequences. Hybrid accumulation is particularly sensitive to gene expression in Δ rnhC ; in cells lacking RnhC, DNA replication is disrupted leading to transversions and structural variation. Our results resolve the outstanding question of how hybrids in native genomic contexts interact with replication to cause mutagenesis and shape genome organization.
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Affiliation(s)
- Jeremy W. Schroeder
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI 53706
| | - Rebecca L. Hurto
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Justin R. Randall
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Katherine J. Wozniak
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Taylor A. Timko
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Taylor M. Nye
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
- Department of Molecular Microbiology and Center for Women’s Infectious Disease Research, Washington University School of Medicine, Saint Louis, MO 63110-1093, USA
| | - Jue D. Wang
- Department of Bacteriology, University of Wisconsin - Madison, Madison, WI 53706
| | - Peter L. Freddolino
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Lyle A. Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
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7
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Patton DL, Cardenas T, Mele P, Navarro J, Sung W. CDMAP/CDVIS: context-dependent mutation analysis package and visualization software. G3 (BETHESDA, MD.) 2022; 13:6887836. [PMID: 36917690 PMCID: PMC10085751 DOI: 10.1093/g3journal/jkac299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/17/2022] [Indexed: 12/15/2022]
Abstract
The Context-dependent Mutation Analysis Package and Visualization Software (CDMAP/CDVIS) is an automated, modular toolkit used for the analysis and visualization of context-dependent mutation patterns (site-specific variation in mutation rate from neighboring-nucleotide effects). The CDMAP computes context-dependent mutation rates using a Variant Call File (VCF), Genbank file, and reference genome and can generate high-resolution figures to analyze variation in mutation rate across spatiotemporal scales. This algorithm has been benchmarked against mutation accumulation data but can also be used to calculate context-dependent mutation rates for polymorphism or closely related species as long as the input requirements are met. Output from CDMAP can be integrated into CDVIS, an interactive database for visualizing mutation patterns across multiple taxa simultaneously.
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Affiliation(s)
- David L Patton
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223, USA
| | - Thomas Cardenas
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223, USA
| | - Perrin Mele
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223, USA
| | - Jon Navarro
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223, USA
| | - Way Sung
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC, 28223, USA
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8
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McLean EK, Nye TM, Lowder FC, Simmons LA. The Impact of RNA-DNA Hybrids on Genome Integrity in Bacteria. Annu Rev Microbiol 2022; 76:461-480. [PMID: 35655343 PMCID: PMC9527769 DOI: 10.1146/annurev-micro-102521-014450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
During the essential processes of DNA replication and transcription, RNA-DNA hybrid intermediates are formed that pose significant risks to genome integrity when left unresolved. To manage RNA-DNA hybrids, all cells rely on RNase H family enzymes that specifically cleave the RNA portion of the many different types of hybrids that form in vivo. Recent experimental advances have provided new insight into how RNA-DNA hybrids form and the consequences to genome integrity that ensue when persistent hybrids remain unresolved. Here we review the types of RNA-DNA hybrids, including R-loops, RNA primers, and ribonucleotide misincorporations, that form during DNA replication and transcription and discuss how each type of hybrid can contribute to genome instability in bacteria. Further, we discuss how bacterial RNase HI, HII, and HIII and bacterial FEN enzymes contribute to genome maintenance through the resolution of hybrids.
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Affiliation(s)
- Emma K McLean
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
| | - Taylor M Nye
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
- Current affiliation: Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Frances C Lowder
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
| | - Lyle A Simmons
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA;
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9
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Abstract
Bacteria are continuously exposed to numerous endogenous and exogenous DNA-damaging agents. To maintain genome integrity and ensure cell survival, bacteria have evolved several DNA repair pathways to correct different types of DNA damage and non-canonical bases, including strand breaks, nucleotide modifications, cross-links, mismatches and ribonucleotide incorporations. Recent advances in genome-wide screens, the availability of thousands of whole-genome sequences and advances in structural biology have enabled the rapid discovery and characterization of novel bacterial DNA repair pathways and new enzymatic activities. In this Review, we discuss recent advances in our understanding of base excision repair and nucleotide excision repair, and we discuss several new repair processes including the EndoMS mismatch correction pathway and the MrfAB excision repair system.
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Affiliation(s)
- Katherine J Wozniak
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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10
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Liu H, Zhang J. Testing the adaptive hypothesis of lagging-strand encoding in bacterial genomes. Nat Commun 2022; 13:2628. [PMID: 35552380 PMCID: PMC9098844 DOI: 10.1038/s41467-022-30000-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/12/2021] [Indexed: 11/24/2022] Open
Affiliation(s)
- Haoxuan Liu
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, United States
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, United States.
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11
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Abstract
How do mutational biases influence the process of adaptation? A common assumption is that selection alone determines the course of adaptation from abundant preexisting variation. Yet, theoretical work shows broad conditions under which the mutation rate to a given type of variant strongly influences its probability of contributing to adaptation. Here we introduce a statistical approach to analyzing how mutation shapes protein sequence adaptation. Using large datasets from three different species, we show that the mutation spectrum has a proportional influence on the types of changes fixed in adaptation. We also show via computer simulations that a variety of factors can influence how closely the spectrum of adaptive substitutions reflects the spectrum of variants introduced by mutation. Evolutionary adaptation often occurs by the fixation of beneficial mutations. This mode of adaptation can be characterized quantitatively by a spectrum of adaptive substitutions, i.e., a distribution for types of changes fixed in adaptation. Recent work establishes that the changes involved in adaptation reflect common types of mutations, raising the question of how strongly the mutation spectrum shapes the spectrum of adaptive substitutions. We address this question with a codon-based model for the spectrum of adaptive amino acid substitutions, applied to three large datasets covering thousands of amino acid changes identified in natural and experimental adaptation in Saccharomyces cerevisiae, Escherichia coli, and Mycobacterium tuberculosis. Using species-specific mutation spectra based on prior knowledge, we find that the mutation spectrum has a proportional influence on the spectrum of adaptive substitutions in all three species. Indeed, we find that by inferring the mutation rates that best explain the spectrum of adaptive substitutions, we can accurately recover the species-specific mutation spectra. However, we also find that the predictive power of the model differs substantially between the three species. To better understand these differences, we use population simulations to explore the factors that influence how closely the spectrum of adaptive substitutions mirrors the mutation spectrum. The results show that the influence of the mutation spectrum decreases with increasing mutational supply (Nμ) and that predictive power is strongly affected by the number and diversity of beneficial mutations.
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Context-Dependent Substitution Dynamics in Plastid DNA Across a Wide Range of Taxonomic Groups. J Mol Evol 2022; 90:44-55. [PMID: 35037071 DOI: 10.1007/s00239-021-10040-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/01/2021] [Indexed: 10/19/2022]
Abstract
The influence of neighboring base composition, or context, on substitution bias at fourfold degenerate coding sites and in intergenic regions in plastid DNA is compared across the angiosperms, gymnosperms, ferns, liverworts, chlorophytes, stramenopiles and rhodophytes. An influence of flanking base G + C content on the relative rates of transitions and transversions is observed in all lineages and extends up to four nucleotides from the site of substitution in some. Despite finding context effects in all lineages, significant differences were observed between lineages. Overall, the data suggest that context is a general factor affecting mutation bias in plastid DNA but that the dynamics of the influence have evolved over time. It is also shown that, although there are similar effects of context on substitution bias at fourfold degenerate coding sites and at sites within intergenic regions, there are also small but significant differences, suggesting that there could be some selection on some of these sites and that there could be some difference in the mutation and/or repair process between coding and noncoding DNA.
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Xue Y, Braslavsky I, Quake SR. Temperature effect on polymerase fidelity. J Biol Chem 2021; 297:101270. [PMID: 34695416 PMCID: PMC8592868 DOI: 10.1016/j.jbc.2021.101270] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/24/2021] [Accepted: 09/29/2021] [Indexed: 11/21/2022] Open
Abstract
The discovery of extremophiles helped enable the development of groundbreaking technology such as PCR. Temperature variation is often an essential step of these technology platforms, but the effect of temperature on the error rate of polymerases from different origins is underexplored. Here, we applied high-throughput sequencing to profile the error rates of DNA polymerases from psychrophilic, mesophilic, and thermophilic origins with single-molecule resolution. We found that the reaction temperature substantially increases substitution and deletion error rates of psychrophilic and mesophilic DNA polymerases. Our motif analysis shows that the substitution error profiles cluster according to phylogenetic similarity of polymerases, not the reaction temperature, thus suggesting that the reaction temperature increases the global error rate of polymerases independent of the sequence context. Intriguingly, we also found that the DNA polymerase I of psychrophilic bacteria exhibits higher polymerization activity than its mesophilic ortholog across all temperature ranges, including down to -19 °C, which is well below the freezing temperature of water. Our results provide a useful reference for how the reaction temperature, a crucial parameter of biochemistry, can affect DNA polymerase fidelity in organisms adapted to a wide range of thermal environments.
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Affiliation(s)
- Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Ido Braslavsky
- The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, California, USA; Department of Applied Physics, Stanford University, Stanford, California, USA; Chan Zuckerberg Biohub, Mission Bay, California, USA.
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DNA Replication-Transcription Conflicts Do Not Significantly Contribute to Spontaneous Mutations Due to Replication Errors in Escherichia coli. mBio 2021; 12:e0250321. [PMID: 34634932 PMCID: PMC8510543 DOI: 10.1128/mbio.02503-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Encounters between DNA replication and transcription can cause genomic disruption, particularly when the two meet head-on. Whether these conflicts produce point mutations is debated. This paper presents detailed analyses of a large collection of mutations generated during mutation accumulation experiments with mismatch repair (MMR)-defective Escherichia coli. With MMR absent, mutations are primarily due to DNA replication errors. Overall, there were no differences in the frequencies of base pair substitutions or small indels (i.e., insertion and deletions of ≤4 bp) in the coding sequences or promoters of genes oriented codirectionally versus head-on to replication. Among a subset of highly expressed genes, there was a 2- to 3-fold bias for indels in genes oriented head-on to replication, but this difference was almost entirely due to the asymmetrical genomic locations of tRNA genes containing mononucleotide runs, which are hot spots for indels. No additional orientation bias in mutation frequencies occurred when MMR− strains were also defective for transcription-coupled repair (TCR). However, in contrast to other reports, loss of TCR slightly increased the overall mutation rate, meaning that TCR is antimutagenic. There was no orientation bias in mutation frequencies among the stress response genes that are regulated by RpoS or induced by DNA damage. Thus, biases in the locations of mutational targets can account for most, if not all, apparent biases in mutation frequencies between genes oriented head-on versus codirectional to replication. In addition, the data revealed a strong correlation of the frequency of base pair substitutions with gene length but no correlation with gene expression levels.
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Abstract
Staphylococcus aureus is a common cause of both superficial and invasive infections of humans and animals. Despite a potent host response and apparently appropriate antibiotic therapy, staphylococcal infections frequently become chronic or recurrent, demonstrating a remarkable ability of S. aureus to withstand the hostile host environment. There is growing evidence that staphylococcal DNA repair makes important contributions to the survival of the pathogen in host tissues, as well as promoting the emergence of mutants that resist host defenses and antibiotics. While much of what we know about DNA repair in S. aureus is inferred from studies with model organisms, the roles of specific repair mechanisms in infection are becoming clear and differences with Bacillus subtilis and Escherichia coli have been identified. Furthermore, there is growing interest in staphylococcal DNA repair as a target for novel therapeutics that sensitize the pathogen to host defenses and antibiotics. In this review, we discuss what is known about staphylococcal DNA repair and its role in infection, examine how repair in S. aureus is similar to, or differs from, repair in well-characterized model organisms, and assess the potential of staphylococcal DNA repair as a novel therapeutic target.
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Sun J, Zhang Y, Wang M, Guan Q, Yang X, Ou JX, Yan M, Wang C, Zhang Y, Li ZH, Lan C, Mao C, Zhou HW, Hao B, Zhang Z. The Biological Significance of Multi-copy Regions and Their Impact on Variant Discovery. GENOMICS, PROTEOMICS & BIOINFORMATICS 2020; 18:516-524. [PMID: 32827758 PMCID: PMC8377240 DOI: 10.1016/j.gpb.2019.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/07/2019] [Accepted: 06/06/2019] [Indexed: 11/23/2022]
Abstract
Identification of genetic variants via high-throughput sequencing (HTS) technologies has been essential for both fundamental and clinical studies. However, to what extent the genome sequence composition affects variant calling remains unclear. In this study, we identified 63,897 multi-copy sequences (MCSs) with a minimum length of 300 bp, each of which occurs at least twice in the human genome. The 151,749 genomic loci (multi-copy regions, or MCRs) harboring these MCSs account for 1.98% of the genome and are distributed unevenly across chromosomes. MCRs containing the same MCS tend to be located on the same chromosome. Gene Ontology (GO) analyses revealed that 3800 genes whose UTRs or exons overlap with MCRs are enriched for Golgi-related cellular component terms and various enzymatic activities in the GO biological function category. MCRs are also enriched for loci that are sensitive to neocarzinostatin-induced double-strand breaks. Moreover, genetic variants discovered by genome-wide association studies and recorded in dbSNP are significantly underrepresented in MCRs. Using simulated HTS datasets, we show that false variant discovery rates are significantly higher in MCRs than in other genomic regions. These results suggest that extra caution must be taken when identifying genetic variants in the MCRs via HTS technologies.
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Affiliation(s)
- Jing Sun
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China; Center for Precision Medicine, Shunde Hospital of Southern Medical University, Foshan 528399, China
| | - Yanfang Zhang
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China
| | - Minhui Wang
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Qian Guan
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Xiujia Yang
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China
| | - Jin Xia Ou
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Mingchen Yan
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Chengrui Wang
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yan Zhang
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhi-Hao Li
- Division of Epidemiology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Chunhong Lan
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China; Center for Precision Medicine, Shunde Hospital of Southern Medical University, Foshan 528399, China
| | - Chen Mao
- Division of Epidemiology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hong-Wei Zhou
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Bingtao Hao
- Center for Precision Medicine, Shunde Hospital of Southern Medical University, Foshan 528399, China.
| | - Zhenhai Zhang
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China; Center for Precision Medicine, Shunde Hospital of Southern Medical University, Foshan 528399, China.
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17
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Schroeder JW, Sankar TS, Wang JD, Simmons LA. The roles of replication-transcription conflict in mutagenesis and evolution of genome organization. PLoS Genet 2020; 16:e1008987. [PMID: 32853297 PMCID: PMC7451550 DOI: 10.1371/journal.pgen.1008987] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Replication-transcription conflicts promote mutagenesis and give rise to evolutionary signatures, with fundamental importance to genome stability ranging from bacteria to metastatic cancer cells. This review focuses on the interplay between replication-transcription conflicts and the evolution of gene directionality. In most bacteria, the majority of genes are encoded on the leading strand of replication such that their transcription is co-directional with the direction of DNA replication fork movement. This gene strand bias arises primarily due to negative selection against deleterious consequences of head-on replication-transcription conflict. However, many genes remain head-on. Can head-on orientation provide some benefit? We combine insights from both mechanistic and evolutionary studies, review published work, and analyze gene expression data to evaluate an emerging model that head-on genes are temporal targets for adaptive mutagenesis during stress. We highlight the alternative explanation that genes in the head-on orientation may simply be the result of genomic inversions and relaxed selection acting on nonessential genes. We seek to clarify how the mechanisms of replication-transcription conflict, in concert with other mutagenic mechanisms, balanced by natural selection, have shaped bacterial genome evolution.
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Affiliation(s)
- Jeremy W. Schroeder
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - T. Sabari Sankar
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
| | - Jue D. Wang
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Lyle A. Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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18
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Ferenci T. Irregularities in genetic variation and mutation rates with environmental stresses. Environ Microbiol 2019; 21:3979-3988. [PMID: 31600848 DOI: 10.1111/1462-2920.14822] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/01/2019] [Accepted: 10/03/2019] [Indexed: 11/26/2022]
Abstract
The appearance of new mutations is determined by the equilibrium between DNA error formation and repair. In bacteria like Escherichia coli, stresses are thought shift this balance towards increased mutagenesis. Recent findings, however, suggest a very uneven relationship between stress and mutations. Only a subset of stressful environments increase the net rate of mutation and different forms of nutritional stress (such as oxygen, carbon or phosphorus limitations) result in markedly different mutation rates after similar reductions in growth rate. Moreover, different stresses result in altered mutational spectra, with some increasing transposition and others increasing indel formation. Single-base substitution rates are lower with some stresses than in unstressed bacteria. Indeed, changes to the mix of mutations with stress are more widespread than a marked increase in net mutation rate. Much remains to be learned on how environments have unique mutational signatures and why some stresses are more mutagenic than others. Even beyond stress-induced genetic variation, the fundamental unresolved question in the stress-mutation relationship is the adaptive value of different types of mutations and mutation rates; is transposition, for example, more advantageous under anaerobic conditions? It remains to be investigated whether stress-specific genetic variation impacts on evolvability differentially in distinct environments.
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Affiliation(s)
- Thomas Ferenci
- School of Life and Environmental Sciences, University of Sydney, New South Wales, 2006, Australia
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19
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Dapas M, Sisk R, Legro RS, Urbanek M, Dunaif A, Hayes MG. Family-Based Quantitative Trait Meta-Analysis Implicates Rare Noncoding Variants in DENND1A in Polycystic Ovary Syndrome. J Clin Endocrinol Metab 2019; 104:3835-3850. [PMID: 31038695 PMCID: PMC6660913 DOI: 10.1210/jc.2018-02496] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 04/17/2019] [Indexed: 02/07/2023]
Abstract
CONTEXT Polycystic ovary syndrome (PCOS) is among the most common endocrine disorders of premenopausal women, affecting 5% to15% of this population depending on the diagnostic criteria applied. It is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. PCOS is highly heritable, but only a small proportion of this heritability can be accounted for by the common genetic susceptibility variants identified to date. OBJECTIVE The objective of this study was to test whether rare genetic variants contribute to PCOS pathogenesis. DESIGN, PATIENTS, AND METHODS We performed whole-genome sequencing on DNA from 261 individuals from 62 families with one or more daughters with PCOS. We tested for associations of rare variants with PCOS and its concomitant hormonal traits using a quantitative trait meta-analysis. RESULTS We found rare variants in DENND1A (P = 5.31 × 10-5, adjusted P = 0.039) that were significantly associated with reproductive and metabolic traits in PCOS families. CONCLUSIONS Common variants in DENND1A have previously been associated with PCOS diagnosis in genome-wide association studies. Subsequent studies indicated that DENND1A is an important regulator of human ovarian androgen biosynthesis. Our findings provide additional evidence that DENND1A plays a central role in PCOS and suggest that rare noncoding variants contribute to disease pathogenesis.
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Affiliation(s)
- Matthew Dapas
- Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ryan Sisk
- Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Richard S Legro
- Department of Obstetrics and Gynecology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Margrit Urbanek
- Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Center for Reproductive Science, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Andrea Dunaif
- Division of Endocrinology, Diabetes, and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, New York
| | - M Geoffrey Hayes
- Division of Endocrinology, Metabolism, and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Department of Anthropology, Northwestern University, Evanston, Illinois
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20
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Kuzminov A. Half-Intercalation Stabilizes Slipped Mispairing and Explains Genome Vulnerability to Frameshift Mutagenesis by Endogenous "Molecular Bookmarks". Bioessays 2019; 41:e1900062. [PMID: 31379009 DOI: 10.1002/bies.201900062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/06/2019] [Indexed: 01/11/2023]
Abstract
Some 60 years ago chemicals that intercalate between base pairs of duplex DNA were found to amplify frameshift mutagenesis. Surprisingly, the robust induction of frameshifts by intercalators still lacks a mechanistic model, leaving this classic phenomenon annoyingly intractable. A promising idea of asymmetric half-intercalation-stabilizing frameshift intermediates during DNA synthesis has never been developed into a model. Instead, researchers of frameshift mutagenesis embraced the powerful slipped-mispairing concept that unexpectedly struggled with the role of intercalators in frameshifting. It is proposed that the slipped mispairing and the half-intercalation ideas are two sides of the same coin. Further, existing findings are reviewed to test predictions of the combined "half-intercalation into the slipped-mispairing intermediate" model against accumulated knowledge. The existence of potential endogenous intercalators and the phenomenon of "DNA bookmarks" reveal ample possibilities for natural frameshift mutagenisis in the cell. From this alarming perspective, it is discussed how the cell could prevent genome deterioration from frameshift mutagenesis.
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Affiliation(s)
- Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, B103 CLSL, 601 South Goodwin Ave, Urbana, IL, 61801-3709, USA
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21
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de Paz AM, Cybulski TR, Marblestone AH, Zamft BM, Church GM, Boyden ES, Kording KP, Tyo KEJ. High-resolution mapping of DNA polymerase fidelity using nucleotide imbalances and next-generation sequencing. Nucleic Acids Res 2019; 46:e78. [PMID: 29718339 PMCID: PMC6061839 DOI: 10.1093/nar/gky296] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 04/12/2018] [Indexed: 02/06/2023] Open
Abstract
DNA polymerase fidelity is affected by both intrinsic properties and environmental conditions. Current strategies for measuring DNA polymerase error rate in vitro are constrained by low error subtype sensitivity, poor scalability, and lack of flexibility in types of sequence contexts that can be tested. We have developed the Magnification via Nucleotide Imbalance Fidelity (MagNIFi) assay, a scalable next-generation sequencing assay that uses a biased deoxynucleotide pool to quantitatively shift error rates into a range where errors are frequent and hence measurement is robust, while still allowing for accurate mapping to error rates under typical conditions. This assay is compatible with a wide range of fidelity-modulating conditions, and enables high-throughput analysis of sequence context effects on base substitution and single nucleotide deletion fidelity using a built-in template library. We validate this assay by comparing to previously established fidelity metrics, and use it to investigate neighboring sequence-mediated effects on fidelity for several DNA polymerases. Through these demonstrations, we establish the MagNIFi assay for robust, high-throughput analysis of DNA polymerase fidelity.
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Affiliation(s)
- Alexandra M de Paz
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL 60208, USA
| | - Thaddeus R Cybulski
- Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL 60611, USA
| | - Adam H Marblestone
- Biophysics Program, Harvard University, Boston, MA 02115, USA.,Wyss Institute, Harvard University, Boston, MA 02115, USA
| | - Bradley M Zamft
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - George M Church
- Biophysics Program, Harvard University, Boston, MA 02115, USA.,Wyss Institute, Harvard University, Boston, MA 02115, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Edward S Boyden
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,McGovern Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Konrad P Kording
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Keith E J Tyo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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22
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Demongeot J, Seligmann H. Theoretical minimal RNA rings designed according to coding constraints mimic deamination gradients. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2019; 106:44. [DOI: 10.1007/s00114-019-1638-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 11/27/2022]
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23
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Payne JL, Menardo F, Trauner A, Borrell S, Gygli SM, Loiseau C, Gagneux S, Hall AR. Transition bias influences the evolution of antibiotic resistance in Mycobacterium tuberculosis. PLoS Biol 2019; 17:e3000265. [PMID: 31083647 PMCID: PMC6532934 DOI: 10.1371/journal.pbio.3000265] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 05/23/2019] [Accepted: 04/26/2019] [Indexed: 11/21/2022] Open
Abstract
Transition bias, an overabundance of transitions relative to transversions, has been widely reported among studies of the rates and spectra of spontaneous mutations. However, demonstrating the role of transition bias in adaptive evolution remains challenging. In particular, it is unclear whether such biases direct the evolution of bacterial pathogens adapting to treatment. We addressed this challenge by analyzing adaptive antibiotic-resistance mutations in the major human pathogen Mycobacterium tuberculosis (MTB). We found strong evidence for transition bias in two independently curated data sets comprising 152 and 208 antibiotic-resistance mutations. This was true at the level of mutational paths (distinct adaptive DNA sequence changes) and events (individual instances of the adaptive DNA sequence changes) and across different genes and gene promoters conferring resistance to a diversity of antibiotics. It was also true for mutations that do not code for amino acid changes (in gene promoters and the 16S ribosomal RNA gene rrs) and for mutations that are synonymous to each other and are therefore likely to have similar fitness effects, suggesting that transition bias can be caused by a bias in mutation supply. These results point to a central role for transition bias in determining which mutations drive adaptive antibiotic resistance evolution in a key pathogen. Some types of mutations occur more frequently than expected. This study shows that such bias —an excess of transitions over transversions—influences the evolution of antibiotic resistance in a key global pathogen, Mycobacterium tuberculosis.
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Affiliation(s)
- Joshua L. Payne
- Institute of Integrative Biology, ETH Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- * E-mail:
| | - Fabrizio Menardo
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Andrej Trauner
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sonia Borrell
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sebastian M. Gygli
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Chloe Loiseau
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sebastien Gagneux
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Alex R. Hall
- Institute of Integrative Biology, ETH Zurich, Switzerland
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24
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Gong B, Zhang H, Huang L, Chen Y, Shi Y, Tam POS, Zhu X, Huang Y, Lei B, Sundaresan P, Li X, Jiang L, Yang J, Lin Y, Lu F, Chen L, Li Y, Leung CKS, Guo X, Zhang S, Huang G, Wu Y, Zhou T, Shuai P, Tham CCY, Weisschuh N, Krishnadas SR, Mardin C, Reis A, Yang J, Zhang L, Zhou Y, Wang Z, Qu C, Shaw PX, Pang CP, Sun X, Zhu W, Li DY, Pasutto F, Yang Z. Mutant RAMP2 causes primary open-angle glaucoma via the CRLR-cAMP axis. Genet Med 2019; 21:2345-2354. [PMID: 31000793 DOI: 10.1038/s41436-019-0507-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 03/20/2019] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide and mutations in known genes can only explain 5-6% of POAG. This study was conducted to identify novel POAG-causing genes and explore the pathogenesis of this disease. METHODS Exome sequencing was performed in a Han Chinese cohort comprising 398 sporadic cases with POAG and 2010 controls, followed by replication studies by Sanger sequencing. A heterozygous Ramp2 knockout mouse model was generated for in vivo functional study. RESULTS Using exome sequencing analysis and replication studies, we identified pathogenic variants in receptor activity-modifying protein 2 (RAMP2) within three genetically diverse populations (Han Chinese, German, and Indian). Six heterozygous RAMP2 pathogenic variants (Glu39Asp, Glu54Lys, Phe103Ser, Asn113Lysfs*10, Glu143Lys, and Ser171Arg) were identified among 16 of 4763 POAG patients, whereas no variants were detected in any exon of RAMP2 in 10,953 control individuals. Mutant RAMP2s aggregated in transfected cells and resulted in damage to the AM-RAMP2/CRLR-cAMP signaling pathway. Ablation of one Ramp2 allele led to cAMP reduction and retinal ganglion cell death in mice. CONCLUSION This study demonstrated that disruption of RAMP2/CRLR-cAMP axis could cause POAG and identified a potential therapeutic intervention for POAG.
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Affiliation(s)
- Bo Gong
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China
| | - Houbin Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lulin Huang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yuhong Chen
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat (ENT) Hospital, Fudan University, Shanghai, China
| | - Yi Shi
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Pancy Oi-Sin Tam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xianjun Zhu
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yi Huang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Department of Medicine, Program in Molecular Medicine, University of Utah, Salt Lake City, UT, USA
| | - Bo Lei
- People's Hospital of Zhengzhou University and Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, Zhengzhou, China
| | - Periasamy Sundaresan
- Department of Genetics, Dr. G. Venkataswamy Eye Research Institute, Aravind Medical Research Foundation, India Aravind Hospital, Tamilnadu, India
| | - Xi Li
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Linxin Jiang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Jialiang Yang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ying Lin
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Fang Lu
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lijia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Yuanfeng Li
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | | | - Xiaoxin Guo
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Shanshan Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Guo Huang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yaqi Wu
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Tongdan Zhou
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ping Shuai
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Clement Chee-Yung Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany
| | - Subbaiah Ramasamy Krishnadas
- Department of Genetics, Dr. G. Venkataswamy Eye Research Institute, Aravind Medical Research Foundation, India Aravind Hospital, Tamilnadu, India
| | - Christian Mardin
- Department of Ophthalmology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Jiyun Yang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lin Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat (ENT) Hospital, Fudan University, Shanghai, China
| | - Yu Zhou
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ziyan Wang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Chao Qu
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Peter X Shaw
- Department of Ophthalmology, University of California San Diego, La Jolla, CA, USA
| | - Chi-Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Xinghuai Sun
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat (ENT) Hospital, Fudan University, Shanghai, China
| | - Weiquan Zhu
- Department of Medicine, Program in Molecular Medicine, University of Utah, Salt Lake City, UT, USA
| | - Dean Yaw Li
- Department of Medicine, Program in Molecular Medicine, University of Utah, Salt Lake City, UT, USA
| | - Francesca Pasutto
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Zhenglin Yang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China. .,Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan, China.
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25
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Spatial Vulnerabilities of the Escherichia coli Genome to Spontaneous Mutations Revealed with Improved Duplex Sequencing. Genetics 2018; 210:547-558. [PMID: 30076202 DOI: 10.1534/genetics.118.301345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 07/31/2018] [Indexed: 12/20/2022] Open
Abstract
Investigation of spontaneous mutations by next-generation sequencing technology has attracted extensive attention lately due to the fundamental roles of spontaneous mutations in evolution and pathological processes. However, these studies only focused on the mutations accumulated through many generations during long-term (possibly be years of) culturing, but not the freshly generated mutations that occur at very low frequencies. In this study, we established a molecularly barcoded deep sequencing strategy to detect low abundant spontaneous mutations in genomes of bacteria cell cultures. Genome-wide spontaneous mutations in 15 Escherichia coli cell culture samples were defined with a high confidence (P < 0.01). We also developed a hotspot-calling approach based on the run-length encoding algorithm to find the genomic regions that are vulnerable to the spontaneous mutations. The hotspots for the mutations appeared to be highly conserved across the bacteria samples. Further biological annotation of these regions indicated that most of the spontaneous mutations were located at the repeat domains or nonfunctional domains of the genomes, suggesting the existence of mechanisms that could somehow prevent the occurrence of mutations in crucial genic areas. This study provides a more faithful picture of mutation occurrence and spectra in a single expansion process without long-term culturing.
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Foster PL, Niccum BA, Popodi E, Townes JP, Lee H, MohammedIsmail W, Tang H. Determinants of Base-Pair Substitution Patterns Revealed by Whole-Genome Sequencing of DNA Mismatch Repair Defective Escherichia coli. Genetics 2018; 209:1029-1042. [PMID: 29907647 PMCID: PMC6063221 DOI: 10.1534/genetics.118.301237] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/14/2018] [Indexed: 11/18/2022] Open
Abstract
Mismatch repair (MMR) is a major contributor to replication fidelity, but its impact varies with sequence context and the nature of the mismatch. Mutation accumulation experiments followed by whole-genome sequencing of MMR-defective Escherichia coli strains yielded ≈30,000 base-pair substitutions (BPSs), revealing mutational patterns across the entire chromosome. The BPS spectrum was dominated by A:T to G:C transitions, which occurred predominantly at the center base of 5'NAC3'+5'GTN3' triplets. Surprisingly, growth on minimal medium or at low temperature attenuated these mutations. Mononucleotide runs were also hotspots for BPSs, and the rate at which these occurred increased with run length. Comparison with ≈2000 BPSs accumulated in MMR-proficient strains revealed that both kinds of hotspots appeared in the wild-type spectrum and so are likely to be sites of frequent replication errors. In MMR-defective strains transitions were strand biased, occurring twice as often when A and C rather than T and G were on the lagging-strand template. Loss of nucleotide diphosphate kinase increases the cellular concentration of dCTP, which resulted in increased rates of mutations due to misinsertion of C opposite A and T. In an mmr ndk double mutant strain, these mutations were more frequent when the template A and T were on the leading strand, suggesting that lagging-strand synthesis was more error-prone, or less well corrected by proofreading, than was leading strand synthesis.
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Affiliation(s)
- Patricia L Foster
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Brittany A Niccum
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Ellen Popodi
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Jesse P Townes
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Heewook Lee
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana 47405
| | - Wazim MohammedIsmail
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana 47405
| | - Haixu Tang
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana 47405
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Lang KS, Merrikh H. The Clash of Macromolecular Titans: Replication-Transcription Conflicts in Bacteria. Annu Rev Microbiol 2018; 72:71-88. [PMID: 29856930 DOI: 10.1146/annurev-micro-090817-062514] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Within the last decade, it has become clear that DNA replication and transcription are routinely in conflict with each other in growing cells. Much of the seminal work on this topic has been carried out in bacteria, specifically, Escherichia coli and Bacillus subtilis; therefore, studies of conflicts in these species deserve special attention. Collectively, the recent findings on conflicts have fundamentally changed the way we think about DNA replication in vivo. Furthermore, new insights on this topic have revealed that the conflicts between replication and transcription significantly influence many key parameters of cellular function, including genome organization, mutagenesis, and evolution of stress response and virulence genes. In this review, we discuss the consequences of replication-transcription conflicts on the life of bacteria and describe some key strategies cells use to resolve them. We put special emphasis on two critical aspects of these encounters: ( a) the consequences of conflicts on replisome stability and dynamics, and ( b) the resulting increase in spontaneous mutagenesis.
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Affiliation(s)
- Kevin S Lang
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA;
| | - Houra Merrikh
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA; .,Department of Genome Sciences, University of Washington, Seattle, Washington 98195-5061, USA
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28
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Li Y, Schroeder JW, Simmons LA, Biteen JS. Visualizing bacterial DNA replication and repair with molecular resolution. Curr Opin Microbiol 2018; 43:38-45. [PMID: 29197672 PMCID: PMC5984126 DOI: 10.1016/j.mib.2017.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/28/2017] [Accepted: 11/06/2017] [Indexed: 10/18/2022]
Abstract
Although DNA replication and repair in bacteria have been extensively studied for many decades, in recent years the development of single-molecule microscopy has provided a new perspective on these fundamental processes. Because single-molecule imaging super-resolves the nanometer-scale dynamics of molecules, and because single-molecule imaging is sensitive to heterogeneities within a sample, this nanoscopic microscopy technique measures the motions, localizations, and interactions of proteins in real time without averaging ensemble observations, both in vitro and in vivo. In this Review, we provide an overview of several recent single-molecule fluorescence microscopy studies on DNA replication and repair. These experiments have shown that, in both Escherichia coli and Bacillus subtilis the DNA replication proteins are highly dynamic. In particular, even highly processive replicative DNA polymerases exchange to and from the replication fork on the scale of a few seconds. Furthermore, single-molecule investigations of the DNA mismatch repair (MMR) pathway have measured the complex interactions between MMR proteins, replication proteins, and DNA. Single-molecule imaging will continue to improve our understanding of fundamental processes in bacteria including DNA replication and repair.
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Affiliation(s)
- Yilai Li
- University of Michigan, Ann Arbor, MI 48109, United States
| | - Jeremy W Schroeder
- University of Michigan, Ann Arbor, MI 48109, United States; University of Wisconsin, Madison, WI 53706, United States
| | - Lyle A Simmons
- University of Michigan, Ann Arbor, MI 48109, United States
| | - Julie S Biteen
- University of Michigan, Ann Arbor, MI 48109, United States.
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29
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Abstract
Cells regulate the activity of genes in a variety of ways. For example, they regulate transcription through DNA binding proteins called transcription factors, and they regulate mRNA stability and processing through RNA binding proteins. Based on current knowledge, transcriptional regulation is more widespread and is involved in many more evolutionary adaptations than posttranscriptional regulation. The reason could be that transcriptional regulation is studied more intensely. We suggest instead that transcriptional regulation harbors an intrinsic evolutionary advantage: when mutations change transcriptional regulation, they are more likely to bring forth novel patterns of such regulation. That is, transcriptional regulation is more evolvable. Our analysis suggests a reason why a specific kind of gene regulation is especially abundant in the living world. Much of gene regulation is carried out by proteins that bind DNA or RNA molecules at specific sequences. One class of such proteins is transcription factors, which bind short DNA sequences to regulate transcription. Another class is RNA binding proteins, which bind short RNA sequences to regulate RNA maturation, transport, and stability. Here, we study the robustness and evolvability of these regulatory mechanisms. To this end, we use experimental binding data from 172 human and fruit fly transcription factors and RNA binding proteins as well as human polymorphism data to study the evolution of binding sites in vivo. We find little difference between the robustness of regulatory protein–RNA interactions and transcription factor–DNA interactions to DNA mutations. In contrast, we find that RNA-mediated regulation is less evolvable than transcriptional regulation, because mutations are less likely to create interactions of an RNA molecule with a new RNA binding protein than they are to create interactions of a gene regulatory region with a new transcription factor. Our observations are consistent with the high level of conservation observed for interactions between RNA binding proteins and their target molecules as well as the evolutionary plasticity of regulatory regions bound by transcription factors. They may help explain why transcriptional regulation is implicated in many more evolutionary adaptations and innovations than RNA-mediated gene regulation.
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Schroeder JW, Yeesin P, Simmons LA, Wang JD. Sources of spontaneous mutagenesis in bacteria. Crit Rev Biochem Mol Biol 2017; 53:29-48. [PMID: 29108429 DOI: 10.1080/10409238.2017.1394262] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mutations in an organism's genome can arise spontaneously, that is, in the absence of exogenous stress and prior to selection. Mutations are often neutral or deleterious to individual fitness but can also provide genetic diversity driving evolution. Mutagenesis in bacteria contributes to the already serious and growing problem of antibiotic resistance. However, the negative impacts of spontaneous mutagenesis on human health are not limited to bacterial antibiotic resistance. Spontaneous mutations also underlie tumorigenesis and evolution of drug resistance. To better understand the causes of genetic change and how they may be manipulated in order to curb antibiotic resistance or the development of cancer, we must acquire a mechanistic understanding of the major sources of mutagenesis. Bacterial systems are particularly well-suited to studying mutagenesis because of their fast growth rate and the panoply of available experimental tools, but efforts to understand mutagenic mechanisms can be complicated by the experimental system employed. Here, we review our current understanding of mutagenic mechanisms in bacteria and describe the methods used to study mutagenesis in bacterial systems.
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Affiliation(s)
- Jeremy W Schroeder
- a Department of Bacteriology , University of Wisconsin - Madison , Madison , WI , USA
| | - Ponlkrit Yeesin
- a Department of Bacteriology , University of Wisconsin - Madison , Madison , WI , USA
| | - Lyle A Simmons
- b Department of Molecular, Cellular, and Developmental Biology , University of Michigan , Ann Arbor , MI , USA
| | - Jue D Wang
- a Department of Bacteriology , University of Wisconsin - Madison , Madison , WI , USA
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31
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Schroeder JW, Randall JR, Hirst WG, O'Donnell ME, Simmons LA. Mutagenic cost of ribonucleotides in bacterial DNA. Proc Natl Acad Sci U S A 2017; 114:11733-11738. [PMID: 29078353 PMCID: PMC5676920 DOI: 10.1073/pnas.1710995114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Replicative DNA polymerases misincorporate ribonucleoside triphosphates (rNTPs) into DNA approximately once every 2,000 base pairs synthesized. Ribonucleotide excision repair (RER) removes ribonucleoside monophosphates (rNMPs) from genomic DNA, replacing the error with the appropriate deoxyribonucleoside triphosphate (dNTP). Ribonucleotides represent a major threat to genome integrity with the potential to cause strand breaks. Furthermore, it has been shown in the bacterium Bacillus subtilis that loss of RER increases spontaneous mutagenesis. Despite the high rNTP error rate and the effect on genome integrity, the mechanism underlying mutagenesis in RER-deficient bacterial cells remains unknown. We performed mutation accumulation lines and genome-wide mutational profiling of B. subtilis lacking RNase HII, the enzyme that incises at single rNMP residues initiating RER. We show that loss of RER in B. subtilis causes strand- and sequence-context-dependent GC → AT transitions. Using purified proteins, we show that the replicative polymerase DnaE is mutagenic within the sequence context identified in RER-deficient cells. We also found that DnaE does not perform strand displacement synthesis. Given the use of nucleotide excision repair (NER) as a backup pathway for RER in RNase HII-deficient cells and the known mutagenic profile of DnaE, we propose that misincorporated ribonucleotides are removed by NER followed by error-prone resynthesis with DnaE.
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Affiliation(s)
- Jeremy W Schroeder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Justin R Randall
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - William G Hirst
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Michael E O'Donnell
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109;
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32
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Raguse M, Torres R, Seco EM, Gándara C, Ayora S, Moeller R, Alonso JC. Bacillus subtilis DisA helps to circumvent replicative stress during spore revival. DNA Repair (Amst) 2017; 59:57-68. [PMID: 28961460 DOI: 10.1016/j.dnarep.2017.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/24/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
The mechanisms that allow to circumvent replicative stress, and to resume DNA synthesis are poorly understood in Bacillus subtilis. To study the role of the diadenylate cyclase DisA and branch migration translocase (BMT) RadA/Sms in restarting a stalled replication fork, we nicked and broke the circular chromosome of an inert mature haploid spore, damaged the bases, and measured survival of reviving spores. During undisturbed ripening, nicks and breaks should be repaired by pathways that do not invoke long-range end resection or genetic exchange by homologous recombination, after which DNA replication might be initiated. We found that DNA damage reduced the viability of spores that lacked DisA, BMT (RadA/Sms, RuvAB or RecG), the Holliday junction resolvase RecU, or the translesion synthesis DNA polymerases (PolY1 or PolY2). DisA and RadA/Sms, in concert with RuvAB, RecG, RecU, PolY1 or PolY2, are needed to bypass replication-blocking lesions. DisA, which binds to stalled or reversed forks, did not apparently affect initiation of PriA-dependent DNA replication in vitro. We propose that DisA is necessary to coordinate responses to replicative stress; it could help to circumvent damaged template bases that otherwise impede fork progression.
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Affiliation(s)
- Marina Raguse
- German Aerospace Center (DLReV), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, D-51147 Cologne (Köln), Germany
| | - Rubén Torres
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Elena M Seco
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Carolina Gándara
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Silvia Ayora
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Ralf Moeller
- German Aerospace Center (DLReV), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Linder Hoehe, D-51147 Cologne (Köln), Germany.
| | - Juan C Alonso
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Cantoblanco, 28049 Madrid, Spain.
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33
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Maharjan RP, Ferenci T. A shifting mutational landscape in 6 nutritional states: Stress-induced mutagenesis as a series of distinct stress input-mutation output relationships. PLoS Biol 2017; 15:e2001477. [PMID: 28594817 PMCID: PMC5464527 DOI: 10.1371/journal.pbio.2001477] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 04/15/2017] [Indexed: 12/16/2022] Open
Abstract
Environmental stresses increase genetic variation in bacteria, plants, and human cancer cells. The linkage between various environments and mutational outcomes has not been systematically investigated, however. Here, we established the influence of nutritional stresses commonly found in the biosphere (carbon, phosphate, nitrogen, oxygen, or iron limitation) on both the rate and spectrum of mutations in Escherichia coli. We found that each limitation was associated with a remarkably distinct mutational profile. Overall mutation rates were not always elevated, and nitrogen, iron, and oxygen limitation resulted in major spectral changes but no net increase in rate. Our results thus suggest that stress-induced mutagenesis is a diverse series of stress input-mutation output linkages that is distinct in every condition. Environment-specific spectra resulted in the differential emergence of traits needing particular mutations in these settings. Mutations requiring transpositions were highest under iron and oxygen limitation, whereas base-pair substitutions and indels were highest under phosphate limitation. The unexpected diversity of input-output effects explains some important phenomena in the mutational biases of evolving genomes. The prevalence of bacterial insertion sequence transpositions in the mammalian gut or in anaerobically stored cultures is due to environmentally determined mutation availability. Likewise, the much-discussed genomic bias towards transition base substitutions in evolving genomes can now be explained as an environment-specific output. Altogether, our conclusion is that environments influence genetic variation as well as selection.
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Affiliation(s)
- Ram P. Maharjan
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Thomas Ferenci
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
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34
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Merrikh CN, Weiss E, Merrikh H. The Accelerated Evolution of Lagging Strand Genes Is Independent of Sequence Context. Genome Biol Evol 2017; 8:3696-3702. [PMID: 28039230 PMCID: PMC5585990 DOI: 10.1093/gbe/evw274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2016] [Indexed: 01/28/2023] Open
Abstract
We previously discovered that lagging strand genes evolve faster in Bacillus subtilis (and potentially other bacteria). Lagging strand genes are transcribed in the head-on orientation with respect to DNA replication, leading to collisions between the two machineries that stall replication and can destabilize genomes. Our previous work indicated that the increased mutagenesis of head-on genes depends on transcription-coupled repair and the activity of an error prone polymerase which is likely activated in response to these collisions. Recently, it was proposed that sequence context is a major contributor to the increased mutagenesis and evolution of head-on genes. These models are based on laboratory-based evolution experiments performed in B. subtilis. However, critical evolutionary analyses of naturally occurring single nucleotide polymorphisms (SNPs) in wild strains were not performed. Using the genomic sequences from nine closely related wild B. subtilis strains, we analyzed over 200,000 naturally occurring SNPs as a proxy for natural mutation patterns for all genes and in particular, head-on genes. Our analysis suggests that (frame-independent) triplet sequence context can impact mutation rates: certain triplet sequences (TAG, CCC, CTA, and ACC) accumulate SNPs at a higher rate and are depleted from the genome. However, the triplet sequences previously identified as mutagenic in laboratory experiments (CCG, GCG, and CAC) do not have an elevated rate of SNP accumulation and are not depleted from the genome. Importantly, dN/dS analyses indicate that the accelerated evolution of head-on genes is not dependent on any particular triplet sequence. Thus, in agreement with our previous results, mutagenic transcription-coupled repair, rather than sequence context, is sufficient to explain the accelerated evolution of head-on genes.
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Affiliation(s)
| | - Eli Weiss
- Microbiology Department, University of Washington, Seattle, USA
| | - Houra Merrikh
- Microbiology Department, University of Washington, Seattle, USA
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35
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Merrikh H. Spatial and Temporal Control of Evolution through Replication-Transcription Conflicts. Trends Microbiol 2017; 25:515-521. [PMID: 28216294 DOI: 10.1016/j.tim.2017.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/10/2017] [Accepted: 01/27/2017] [Indexed: 01/16/2023]
Abstract
Evolution could potentially be accelerated if an organism could selectively increase the mutation rate of specific genes that are actively under positive selection. Recently, a mechanism that cells can use to target rapid evolution to specific genes was discovered. This mechanism is driven by gene orientation-dependent encounters between DNA replication and transcription machineries. These encounters increase mutagenesis in lagging-strand genes, where replication-transcription conflicts are severe. Due to the orientation and transcription-dependent nature of this process, conflict-driven mutagenesis can be used by cells to spatially (gene-specifically) and temporally (only upon transcription induction) regulate the rate of gene evolution. Here, I summarize recent findings on this topic, and discuss the implications of increasing mutagenesis rates and accelerating evolution through active mechanisms.
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Affiliation(s)
- Houra Merrikh
- Department of Microbiology, Health Sciences Building - J-wing, University of Washington, Seattle, WA 98195, USA.
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36
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Shewaramani S, Finn TJ, Leahy SC, Kassen R, Rainey PB, Moon CD. Anaerobically Grown Escherichia coli Has an Enhanced Mutation Rate and Distinct Mutational Spectra. PLoS Genet 2017; 13:e1006570. [PMID: 28103245 PMCID: PMC5289635 DOI: 10.1371/journal.pgen.1006570] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 02/02/2017] [Accepted: 01/04/2017] [Indexed: 12/21/2022] Open
Abstract
Oxidative stress is a major cause of mutation but little is known about how growth in the absence of oxygen impacts the rate and spectrum of mutations. We employed long-term mutation accumulation experiments to directly measure the rates and spectra of spontaneous mutation events in Escherichia coli populations propagated under aerobic and anaerobic conditions. To detect mutations, whole genome sequencing was coupled with methods of analysis sufficient to identify a broad range of mutational classes, including structural variants (SVs) generated by movement of repetitive elements. The anaerobically grown populations displayed a mutation rate nearly twice that of the aerobic populations, showed distinct asymmetric mutational strand biases, and greater insertion element activity. Consistent with mutation rate and spectra observations, genes for transposition and recombination repair associated with SVs were up-regulated during anaerobic growth. Together, these results define differences in mutational spectra affecting the evolution of facultative anaerobes.
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Affiliation(s)
- Sonal Shewaramani
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand
| | - Thomas J. Finn
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand
| | - Sinead C. Leahy
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
| | - Rees Kassen
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Paul B. Rainey
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, Germany
- Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), CNRS UMR 8231, PSL Research University, Paris, France
| | - Christina D. Moon
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
- * E-mail:
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37
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Implementation and Data Analysis of Tn-seq, Whole-Genome Resequencing, and Single-Molecule Real-Time Sequencing for Bacterial Genetics. J Bacteriol 2016; 199:JB.00560-16. [PMID: 27672193 DOI: 10.1128/jb.00560-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Few discoveries have been more transformative to the biological sciences than the development of DNA sequencing technologies. The rapid advancement of sequencing and bioinformatics tools has revolutionized bacterial genetics, deepening our understanding of model and clinically relevant organisms. Although application of newer sequencing technologies to studies in bacterial genetics is increasing, the implementation of DNA sequencing technologies and development of the bioinformatics tools required for analyzing the large data sets generated remain a challenge for many. In this minireview, we have chosen to summarize three sequencing approaches that are particularly useful for bacterial genetics. We provide resources for scientists new to and interested in their application. Here, we discuss the analysis of data from transposon mutagenesis followed by deep sequencing (Tn-seq) to determine gene disruptions differentially represented in a mutant population and Illumina sequencing for identification of suppressor or other mutations, and we summarize single-molecule real-time (SMRT) sequencing for de novo genome assembly and the use of the output data for detection of DNA base modifications.
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38
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Dillon MM, Sung W, Sebra R, Lynch M, Cooper VS. Genome-Wide Biases in the Rate and Molecular Spectrum of Spontaneous Mutations in Vibrio cholerae and Vibrio fischeri. Mol Biol Evol 2016; 34:93-109. [PMID: 27744412 PMCID: PMC5854121 DOI: 10.1093/molbev/msw224] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The vast diversity in nucleotide composition and architecture among bacterial genomes may be partly explained by inherent biases in the rates and spectra of spontaneous mutations. Bacterial genomes with multiple chromosomes are relatively unusual but some are relevant to human health, none more so than the causative agent of cholera, Vibrio cholerae Here, we present the genome-wide mutation spectra in wild-type and mismatch repair (MMR) defective backgrounds of two Vibrio species, the low-%GC squid symbiont V. fischeri and the pathogen V. cholerae, collected under conditions that greatly minimize the efficiency of natural selection. In apparent contrast to their high diversity in nature, both wild-type V. fischeri and V. cholerae have among the lowest rates for base-substitution mutations (bpsms) and insertion-deletion mutations (indels) that have been measured, below 10-3/genome/generation. Vibrio fischeri and V. cholerae have distinct mutation spectra, but both are AT-biased and produce a surprising number of multi-nucleotide indels. Furthermore, the loss of a functional MMR system caused the mutation spectra of these species to converge, implying that the MMR system itself contributes to species-specific mutation patterns. Bpsm and indel rates varied among genome regions, but do not explain the more rapid evolutionary rates of genes on chromosome 2, which likely result from weaker purifying selection. More generally, the very low mutation rates of Vibrio species correlate inversely with their immense population sizes and suggest that selection may not only have maximized replication fidelity but also optimized other polygenic traits relative to the constraints of genetic drift.
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Affiliation(s)
- Marcus M Dillon
- Microbiology Graduate Program, University of New Hampshire, Durham, NH
| | - Way Sung
- Department of Bioinformatics and Genomics, University of North Carolina Charlotte, Charlotte, NC.,Department of Biology, Indiana University, Bloomington, IN
| | - Robert Sebra
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Michael Lynch
- Department of Biology, Indiana University, Bloomington, IN
| | - Vaughn S Cooper
- Microbiology Graduate Program, University of New Hampshire, Durham, NH .,Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA
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Garcia-Mazcorro JF, Barcenas-Walls JR. Thinking beside the box: Should we care about the non-coding strand of the 16S rRNA gene? FEMS Microbiol Lett 2016; 363:fnw171. [DOI: 10.1093/femsle/fnw171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2016] [Indexed: 12/22/2022] Open
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The nature of mutations induced by replication–transcription collisions. Nature 2016; 535:178-81. [PMID: 27362223 PMCID: PMC4945378 DOI: 10.1038/nature18316] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 05/11/2016] [Indexed: 12/18/2022]
Abstract
The DNA replication and transcription machineries share a common DNA template and thus can collide with each other co-directionally or head-on1,2. Replication-transcription collisions can cause replication fork arrest, premature transcription termination, DNA breaks, and recombination intermediates threatening genome integrity1–10. Collisions may also trigger mutations, which are major contributors of genetic disease and evolution5,7,11. However, the nature and mechanisms of collision-induced mutagenesis remain poorly understood. Here we reveal the genetic consequence of replication-transcription collisions in actively dividing bacteria to be two classes of mutations: duplications/deletions and base substitutions in promoters. Both signatures are highly deleterious but are distinct from the well-characterized base substitutions in coding sequence. Duplications/deletions are likely caused by replication stalling events that are triggered by collisions; their distribution patterns are consistent with where the fork first encounters a transcription complex upon entering a transcription unit. Promoter substitutions result mostly from head-on collisions and frequently occur at a nucleotide conserved in promoters recognized by the major sigma factor in bacteria. This substitution is generated via adenine deamination on the template strand in the promoter open complex, as a consequence of head-on replication perturbing transcription initiation. We conclude that replication-transcription collisions induce distinct mutation signatures by antagonizing replication and transcription, not only in coding sequences but also in gene regulatory elements.
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