51
|
Abstract
Natural or synthetic genetic modules can lose their function over long-term evolution if the function is costly. How populations can evolve to restore such broken function is poorly understood. To test the reversibility of evolutionary breakdown, we use yeast cell populations with a chromosomally integrated synthetic gene circuit. In previous evolution experiments the gene circuit lost its costly function through various mutations. By exposing such mutant populations to conditions where regaining gene circuit function would be beneficial, we find adaptation scenarios with or without repairing lost gene circuit function. These results are important for drug resistance or future synthetic biology applications where evolutionary loss and regain of function play a significant role. Evolutionary reversibility—the ability to regain a lost function—is an important problem both in evolutionary and synthetic biology, where repairing natural or synthetic systems broken by evolutionary processes may be valuable. Here, we use a synthetic positive-feedback (PF) gene circuit integrated into haploid Saccharomyces cerevisiae cells to test if the population can restore lost PF function. In previous evolution experiments, mutations in a gene eliminated the fitness costs of PF activation. Since PF activation also provides drug resistance, exposing such compromised or broken mutants to both drug and inducer should create selection pressure to regain drug resistance and possibly PF function. Indeed, evolving 7 PF mutant strains in the presence of drug revealed 3 adaptation scenarios through genomic, PF-external mutations that elevate PF basal expression, possibly by affecting transcription, translation, degradation, and other fundamental cellular processes. Nonfunctional mutants gained drug resistance without ever developing high expression, while quasifunctional and dysfunctional PF mutants developed high expression nongenetically, which then diminished, although more slowly for dysfunctional mutants where revertant clones arose. These results highlight how intracellular context, such as the growth rate, can affect regulatory network dynamics and evolutionary dynamics, which has important consequences for understanding the evolution of drug resistance and developing future synthetic biology applications.
Collapse
|
52
|
Camellato B, Roney IJ, Azizi A, Charlebois D, Kaern M. Engineered gene networks enable non‐genetic drug resistance and enhanced cellular robustness. ENGINEERING BIOLOGY 2019. [DOI: 10.1049/enb.2019.0009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Brendan Camellato
- Ottawa Institute of Systems Biology University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Cellular and Molecular Medicine University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Institute of Systems Genetics New York University Langone Health 550 1st Avenue New York NY 10016 USA
| | - Ian J. Roney
- Ottawa Institute of Systems Biology University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Cellular and Molecular Medicine University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
| | - Afnan Azizi
- Ottawa Institute of Systems Biology University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Cellular and Molecular Medicine University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
| | - Daniel Charlebois
- Ottawa Institute of Systems Biology University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Physics University of Ottawa 150 Louis‐Pasteur Pvt Ottawa Ontario K1N 6N5 Canada
| | - Mads Kaern
- Ottawa Institute of Systems Biology University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Cellular and Molecular Medicine University of Ottawa 451 Smyth Road Ottawa Ontario K1H 8M5 Canada
- Department of Physics University of Ottawa 150 Louis‐Pasteur Pvt Ottawa Ontario K1N 6N5 Canada
| |
Collapse
|
53
|
Spohn R, Daruka L, Lázár V, Martins A, Vidovics F, Grézal G, Méhi O, Kintses B, Számel M, Jangir PK, Csörgő B, Györkei Á, Bódi Z, Faragó A, Bodai L, Földesi I, Kata D, Maróti G, Pap B, Wirth R, Papp B, Pál C. Integrated evolutionary analysis reveals antimicrobial peptides with limited resistance. Nat Commun 2019; 10:4538. [PMID: 31586049 PMCID: PMC6778101 DOI: 10.1038/s41467-019-12364-6] [Citation(s) in RCA: 191] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/27/2019] [Indexed: 12/24/2022] Open
Abstract
Antimicrobial peptides (AMPs) are promising antimicrobials, however, the potential of bacterial resistance is a major concern. Here we systematically study the evolution of resistance to 14 chemically diverse AMPs and 12 antibiotics in Escherichia coli. Our work indicates that evolution of resistance against certain AMPs, such as tachyplesin II and cecropin P1, is limited. Resistance level provided by point mutations and gene amplification is very low and antibiotic-resistant bacteria display no cross-resistance to these AMPs. Moreover, genomic fragments derived from a wide range of soil bacteria confer no detectable resistance against these AMPs when introduced into native host bacteria on plasmids. We have found that simple physicochemical features dictate bacterial propensity to evolve resistance against AMPs. Our work could serve as a promising source for the development of new AMP-based therapeutics less prone to resistance, a feature necessary to avoid any possible interference with our innate immune system.
Collapse
Affiliation(s)
- Réka Spohn
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Lejla Daruka
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Viktória Lázár
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ana Martins
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Fanni Vidovics
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Gábor Grézal
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Orsolya Méhi
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Bálint Kintses
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
| | - Mónika Számel
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Pramod K Jangir
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bálint Csörgő
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- University of California, San Francisco, Department of Microbiology and Immunology, San Francisco, CA, USA
| | - Ádám Györkei
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Zoltán Bódi
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Anikó Faragó
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
| | - László Bodai
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
| | - Imre Földesi
- Department of Laboratory Medicine, University of Szeged, Szeged, Hungary
| | - Diána Kata
- Department of Laboratory Medicine, University of Szeged, Szeged, Hungary
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Bernadett Pap
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Balázs Papp
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- HCEMM-BRC Metabolic Systems Biology Lab, Szeged, Hungary
| | - Csaba Pál
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary.
| |
Collapse
|
54
|
Geller SH, Antwi EB, Di Ventura B, McClean MN. Optogenetic Repressors of Gene Expression in Yeasts Using Light-Controlled Nuclear Localization. Cell Mol Bioeng 2019; 12:511-528. [PMID: 31719930 PMCID: PMC6816687 DOI: 10.1007/s12195-019-00598-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 09/03/2019] [Indexed: 01/30/2023] Open
Abstract
INTRODUCTION Controlling gene expression is a fundamental goal of basic and synthetic biology because it allows insight into cellular function and control of cellular activity. We explored the possibility of generating an optogenetic repressor of gene expression in the model organism Saccharomyces cerevisiae by using light to control the nuclear localization of nuclease-dead Cas9, dCas9. METHODS The dCas9 protein acts as a repressor for a gene of interest when localized to the nucleus in the presence of an appropriate guide RNA (sgRNA). We engineered dCas9, the mammalian transcriptional repressor Mxi1, and an optogenetic tool to control nuclear localization (LINuS) as parts in an existing yeast optogenetic toolkit. This allowed expression cassettes containing novel dCas9 repressor configurations and guide RNAs to be rapidly constructed and integrated into yeast. RESULTS Our library of repressors displays a range of basal repression without the need for inducers or promoter modification. Populations of cells containing these repressors can be combined to generate a heterogeneous population of yeast with a 100-fold expression range. We find that repression can be dialed modestly in a light dose- and intensity-dependent manner. We used this library to repress expression of the lanosterol 14-alpha-demethylase Erg11, generating yeast with a range of sensitivity to the important antifungal drug fluconazole. CONCLUSIONS This toolkit will be useful for spatiotemporal perturbation of gene expression in Saccharomyces cerevisiae. Additionally, we believe that the simplicity of our scheme will allow these repressors to be easily modified to control gene expression in medically relevant fungi, such as pathogenic yeasts.
Collapse
Affiliation(s)
- Stephanie H. Geller
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 Engineering Drive, Madison, WI 53706 USA
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, 1525 Linden Dr., Madison, WI 53706 USA
| | - Enoch B. Antwi
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
- Heidelberg Biosciences International Graduate School (HBIGS), 69120 Heidelberg, Germany
| | - Barbara Di Ventura
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Megan N. McClean
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 Engineering Drive, Madison, WI 53706 USA
| |
Collapse
|
55
|
Bacterial Heterogeneity and Antibiotic Survival: Understanding and Combatting Persistence and Heteroresistance. Mol Cell 2019; 76:255-267. [DOI: 10.1016/j.molcel.2019.09.028] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/20/2019] [Accepted: 09/23/2019] [Indexed: 12/20/2022]
|
56
|
Draghi J. Phenotypic variability can promote the evolution of adaptive plasticity by reducing the stringency of natural selection. J Evol Biol 2019; 32:1274-1289. [DOI: 10.1111/jeb.13527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Jeremy Draghi
- Department of Biological Sciences Virginia Tech Blacksburg VA USA
- Department of Biology Brooklyn College CUNY Brooklyn NY USA
- The Graduate Center of the City University of New York New York NY USA
| |
Collapse
|
57
|
Perpetuini G, Tittarelli F, Mattarelli P, Modesto M, Cilli E, Suzzi G, Tofalo R. Intraspecies polymorphisms of Kluyveromyces marxianus strains from Yaghnob valley. FEMS Microbiol Lett 2019; 365:4834011. [PMID: 29401260 DOI: 10.1093/femsle/fny028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/31/2018] [Indexed: 02/07/2023] Open
Abstract
In this study, 29 strains of Kluyveromyces marxianus with peculiar genetic and phenotypic traits previously isolated from a fermented goat milk of Yaghnob valley were investigated for chromosome length polymorphism (CLP) by PFGE, adhesion properties and carbon usage by Biolog analysis. Obtained data showed that strains differed in terms of number and size of chromosome bands. The number of bands ranged from 5 to 7, suggesting a probable genome size from 1.4 to 2.6 Mb. Strains showed a certain level of cell surface hydrophobicity ranging from 32% to 77.7%. Strains were also tested for their ability to form a biofilm on polystyrene plates: planktonic cells ranged from 6.3 cfu/mL to 7.95 cfu/mL, while sessile from 7.11 cfu/mL to 8.6 cfu/mL. The strains able to adhere to polystyrene plates were also able to form a mature MAT. Biolog analysis revealed that almost all strains were able to use putrescine, malic acid, α-D lactose, phenylethylamine, β-methyl D-gucoside and xylose; 5 strains were able to grow on cellobiose and 3 were able to catabolise α-ketobutyric. The obtained data highlighted a number of interesting features underlying the peculiar capacities of these strains for industrial applications.
Collapse
Affiliation(s)
- Giorgia Perpetuini
- Department of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, Teramo 64100, Italy.,Department of Agricultural Sciences, University of Bologna, Viale Fanin 42, I-40127 Bologna, Italy
| | - Fabrizia Tittarelli
- Department of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, Teramo 64100, Italy
| | - Paola Mattarelli
- Department of Agricultural Sciences, University of Bologna, Viale Fanin 42, I-40127 Bologna, Italy
| | - Monica Modesto
- Department of Agricultural Sciences, University of Bologna, Viale Fanin 42, I-40127 Bologna, Italy
| | - Elisabetta Cilli
- Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, I-48121 Ravenna, Italy
| | | | - Rosanna Tofalo
- Department of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, Teramo 64100, Italy
| |
Collapse
|
58
|
Rapid Evolution of Reduced Susceptibility against a Balanced Dual-Targeting Antibiotic through Stepping-Stone Mutations. Antimicrob Agents Chemother 2019; 63:AAC.00207-19. [PMID: 31235632 DOI: 10.1128/aac.00207-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/14/2019] [Indexed: 11/20/2022] Open
Abstract
Multitargeting antibiotics, i.e., single compounds capable of inhibiting two or more bacterial targets, are generally considered to be a promising therapeutic strategy against resistance evolution. The rationale for this theory is that multitargeting antibiotics demand the simultaneous acquisition of multiple mutations at their respective target genes to achieve significant resistance. The theory presumes that individual mutations provide little or no benefit to the bacterial host. Here, we propose that such individual stepping-stone mutations can be prevalent in clinical bacterial isolates, as they provide significant resistance to other antimicrobial agents. To test this possibility, we focused on gepotidacin, an antibiotic candidate that selectively inhibits both bacterial DNA gyrase and topoisomerase IV. In a susceptible organism, Klebsiella pneumoniae, a combination of two specific mutations in these target proteins provide an >2,000-fold reduction in susceptibility, while individually, none of these mutations affect resistance significantly. Alarmingly, strains with decreased susceptibility against gepotidacin are found to be as virulent as the wild-type Klebsiella pneumoniae strain in a murine model. Moreover, numerous pathogenic isolates carry mutations which could promote the evolution of clinically significant reduction of susceptibility against gepotidacin in the future. As might be expected, prolonged exposure to ciprofloxacin, a clinically widely employed gyrase inhibitor, coselected for reduced susceptibility against gepotidacin. We conclude that extensive antibiotic usage could select for mutations that serve as stepping-stones toward resistance against antimicrobial compounds still under development. Our research indicates that even balanced multitargeting antibiotics are prone to resistance evolution.
Collapse
|
59
|
Uphoff S. A Quantitative Model Explains Single-Cell Dynamics of the Adaptive Response in Escherichia coli. Biophys J 2019; 117:1156-1165. [PMID: 31466698 PMCID: PMC6818145 DOI: 10.1016/j.bpj.2019.08.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 07/26/2019] [Accepted: 08/12/2019] [Indexed: 01/05/2023] Open
Abstract
DNA damage caused by alkylating chemicals induces an adaptive response in Escherichia coli that increases the tolerance of cells to further damage. Signaling of the response occurs through irreversible methylation of the Ada protein, which acts as a DNA repair protein and damage sensor. Methylated Ada induces its own gene expression through a positive feedback loop. However, random fluctuations in the abundance of Ada jeopardize the reliability of the induction signal. I developed a quantitative model to test how gene expression noise and feedback amplification affect the fidelity of the adaptive response. A remarkably simple model accurately reproduced experimental observations from single-cell measurements of gene expression dynamics in a microfluidic device. Stochastic simulations showed that delays in the adaptive response are a direct consequence of the very low number of Ada molecules present to signal DNA damage. For cells that have zero copies of Ada, response activation becomes a memoryless process that is dictated by an exponential waiting time distribution between basal Ada expression events. Experiments also confirmed the model prediction that the strength of the adaptive response drops with an increasing growth rate of cells.
Collapse
Affiliation(s)
- Stephan Uphoff
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
60
|
Diaz-Uriarte R, Vasallo C. Every which way? On predicting tumor evolution using cancer progression models. PLoS Comput Biol 2019; 15:e1007246. [PMID: 31374072 PMCID: PMC6693785 DOI: 10.1371/journal.pcbi.1007246] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 08/14/2019] [Accepted: 07/05/2019] [Indexed: 11/18/2022] Open
Abstract
Successful prediction of the likely paths of tumor progression is valuable for diagnostic, prognostic, and treatment purposes. Cancer progression models (CPMs) use cross-sectional samples to identify restrictions in the order of accumulation of driver mutations and thus CPMs encode the paths of tumor progression. Here we analyze the performance of four CPMs to examine whether they can be used to predict the true distribution of paths of tumor progression and to estimate evolutionary unpredictability. Employing simulations we show that if fitness landscapes are single peaked (have a single fitness maximum) there is good agreement between true and predicted distributions of paths of tumor progression when sample sizes are large, but performance is poor with the currently common much smaller sample sizes. Under multi-peaked fitness landscapes (i.e., those with multiple fitness maxima), performance is poor and improves only slightly with sample size. In all cases, detection regime (when tumors are sampled) is a key determinant of performance. Estimates of evolutionary unpredictability from the best performing CPM, among the four examined, tend to overestimate the true unpredictability and the bias is affected by detection regime; CPMs could be useful for estimating upper bounds to the true evolutionary unpredictability. Analysis of twenty-two cancer data sets shows low evolutionary unpredictability for several of the data sets. But most of the predictions of paths of tumor progression are very unreliable, and unreliability increases with the number of features analyzed. Our results indicate that CPMs could be valuable tools for predicting cancer progression but that, currently, obtaining useful predictions of paths of tumor progression from CPMs is dubious, and emphasize the need for methodological work that can account for the probably multi-peaked fitness landscapes in cancer.
Collapse
Affiliation(s)
- Ramon Diaz-Uriarte
- Department of Biochemistry, Universidad Autónoma de Madrid, Madrid, Spain
- Instituto de Investigaciones Biomédicas “Alberto Sols” (UAM-CSIC), Madrid, Spain
| | - Claudia Vasallo
- Department of Biochemistry, Universidad Autónoma de Madrid, Madrid, Spain
- Instituto de Investigaciones Biomédicas “Alberto Sols” (UAM-CSIC), Madrid, Spain
| |
Collapse
|
61
|
Draghi J. Developmental noise and ecological opportunity across space can release constraints on the evolution of plasticity. Evol Dev 2019; 22:35-46. [PMID: 31356727 DOI: 10.1111/ede.12305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phenotypic plasticity is a potentially definitive solution to environment heterogeneity, driving biologists to understand why it is not ubiquitous in nature. While costs and constraints may limit the success of plasticity, we are still far from a complete theory of when these limitations actually proscribe adaptive plasticity. Here I use a simple model of plasticity incorporating developmental noise to explore the competitive and evolutionary relationships of specialist and generalist genotypes spreading across a heterogeneous landscape. Results show that plasticity can arise in the context of specialism, preadapting genotypes to later evolve toward plastic generalism. Developmental noise helps a mutant with imperfect plasticity successfully compete against its ancestor, providing an evolutionary path by which subsequent mutations can refine plasticity toward its optimum. These results address how the complex selection pressures across a heterogeneous environment can help evolution find paths around constraints arising from developmental mechanisms.
Collapse
Affiliation(s)
- Jeremy Draghi
- Department of Biology, Brooklyn College CUNY, Brooklyn, New York.,The Graduate Center, CUNY, New York, New York.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia
| |
Collapse
|
62
|
Farquhar KS, Charlebois DA, Szenk M, Cohen J, Nevozhay D, Balázsi G. Role of network-mediated stochasticity in mammalian drug resistance. Nat Commun 2019; 10:2766. [PMID: 31235692 PMCID: PMC6591227 DOI: 10.1038/s41467-019-10330-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 05/03/2019] [Indexed: 11/11/2022] Open
Abstract
A major challenge in biology is that genetically identical cells in the same environment can display gene expression stochasticity (noise), which contributes to bet-hedging, drug tolerance, and cell-fate switching. The magnitude and timescales of stochastic fluctuations can depend on the gene regulatory network. Currently, it is unclear how gene expression noise of specific networks impacts the evolution of drug resistance in mammalian cells. Answering this question requires adjusting network noise independently from mean expression. Here, we develop positive and negative feedback-based synthetic gene circuits to decouple noise from the mean for Puromycin resistance gene expression in Chinese Hamster Ovary cells. In low Puromycin concentrations, the high-noise, positive-feedback network delays long-term adaptation, whereas it facilitates adaptation under high Puromycin concentration. Accordingly, the low-noise, negative-feedback circuit can maintain resistance by acquiring mutations while the positive-feedback circuit remains mutation-free and regains drug sensitivity. These findings may have profound implications for chemotherapeutic inefficiency and cancer relapse. The role of gene expression noise in the evolution of drug resistance in mammalian cells is unclear. Here, by uncoupling noise from mean expression of a drug resistance gene in CHO cells the authors show that noisy expression aids adaptation to high drug levels, but delays it at low drug levels.
Collapse
Affiliation(s)
- Kevin S Farquhar
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, 11794, USA.,Genetics and Epigenetics Graduate Program, The University of Texas MD Anderson Cancer Center, UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Daniel A Charlebois
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, 11794, USA.,Department of Physics, University of Alberta, Edmonton, AB, 4-181 CCIS, T6G-2E1, Canada
| | - Mariola Szenk
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, 11794, USA.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Joseph Cohen
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Dmitry Nevozhay
- School of Biomedicine, Far Eastern Federal University, 8 Sukhanova Street, Vladivostok, 690950, Russia.,Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Gábor Balázsi
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, 11794, USA. .,Genetics and Epigenetics Graduate Program, The University of Texas MD Anderson Cancer Center, UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA. .,Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA. .,Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
| |
Collapse
|
63
|
Fernández‐Cabezón L, Cros A, Nikel PI. Evolutionary Approaches for Engineering Industrially Relevant Phenotypes in Bacterial Cell Factories. Biotechnol J 2019; 14:e1800439. [DOI: 10.1002/biot.201800439] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/08/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Lorena Fernández‐Cabezón
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark 2800 Kongens Lyngby Denmark
| | - Antonin Cros
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark 2800 Kongens Lyngby Denmark
| | - Pablo I. Nikel
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of Denmark 2800 Kongens Lyngby Denmark
| |
Collapse
|
64
|
Liu J, François JM, Capp JP. Gene Expression Noise Produces Cell-to-Cell Heterogeneity in Eukaryotic Homologous Recombination Rate. Front Genet 2019; 10:475. [PMID: 31164905 PMCID: PMC6536703 DOI: 10.3389/fgene.2019.00475] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 05/03/2019] [Indexed: 11/13/2022] Open
Abstract
Variation in gene expression among genetically identical individual cells (called gene expression noise) directly contributes to phenotypic diversity. Whether such variation can impact genome stability and lead to variation in genotype remains poorly explored. We addressed this question by investigating whether noise in the expression of genes affecting homologous recombination (HR) activity either directly (RAD52) or indirectly (RAD27) confers cell-to-cell heterogeneity in HR rate in Saccharomyces cerevisiae. Using cell sorting to isolate subpopulations with various expression levels, we show that spontaneous HR rate is highly heterogeneous from cell-to-cell in clonal populations depending on the cellular amount of proteins affecting HR activity. Phleomycin-induced HR is even more heterogeneous, showing that RAD27 expression variation strongly affects the rate of recombination from cell-to-cell. Strong variations in HR rate between subpopulations are not correlated to strong changes in cell cycle stage. Moreover, this heterogeneity occurs even when simultaneously sorting cells at equal expression level of another gene involved in DNA damage response (BMH1) that is upregulated by DNA damage, showing that the initiating DNA damage is not responsible for the observed heterogeneity in HR rate. Thus gene expression noise seems mainly responsible for this phenomenon. Finally, HR rate non-linearly scales with Rad27 levels showing that total amount of HR cannot be explained solely by the time- or population-averaged Rad27 expression. Altogether, our data reveal interplay between heterogeneity at the gene expression and genetic levels in the production of phenotypic diversity with evolutionary consequences from microbial to cancer cell populations.
Collapse
Affiliation(s)
- Jian Liu
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Institut National des Sciences Appliquées de Toulouse, UMR CNRS 5504, UMR INRA 792, Université de Toulouse, Toulouse, France
| | - Jean-Marie François
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Institut National des Sciences Appliquées de Toulouse, UMR CNRS 5504, UMR INRA 792, Université de Toulouse, Toulouse, France
| | - Jean-Pascal Capp
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, Institut National des Sciences Appliquées de Toulouse, UMR CNRS 5504, UMR INRA 792, Université de Toulouse, Toulouse, France
| |
Collapse
|
65
|
de Jong TV, Moshkin YM, Guryev V. Gene expression variability: the other dimension in transcriptome analysis. Physiol Genomics 2019; 51:145-158. [DOI: 10.1152/physiolgenomics.00128.2018] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Transcriptome sequencing is a powerful technique to study molecular changes that underlie the differences in physiological conditions and disease progression. A typical question that is posed in such studies is finding genes with significant changes between sample groups. In this respect expression variability is regarded as a nuisance factor that is primarily of technical origin and complicates the data analysis. However, it is becoming apparent that the biological variation in gene expression might be an important molecular phenotype that can affect physiological parameters. In this review we explore the recent literature on technical and biological variability in gene expression, sources of expression variability, (epi-)genetic hallmarks, and evolutionary constraints in genes with robust and variable gene expression. We provide an overview of recent findings on effects of external cues, such as diet and aging, on expression variability and on other biological phenomena that can be linked to it. We discuss metrics and tools that were developed for quantification of expression variability and highlight the importance of future studies in this direction. To assist the adoption of expression variability analysis, we also provide a detailed description and computer code, which can easily be utilized by other researchers. We also provide a reanalysis of recently published data to highlight the value of the analysis method.
Collapse
Affiliation(s)
- Tristan V. de Jong
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Yuri M. Moshkin
- Institute of Cytology and Genetics, Siberian Branch of RAS, Novosibirsk, Russia
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, Russia
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| |
Collapse
|
66
|
Hinohara K, Polyak K. Intratumoral Heterogeneity: More Than Just Mutations. Trends Cell Biol 2019; 29:569-579. [PMID: 30987806 DOI: 10.1016/j.tcb.2019.03.003] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 12/19/2022]
Abstract
Most human tumors are composed of genetically and phenotypically heterogeneous cancer cell populations, which poses a major challenge for the clinical management of cancer patients. Advances of single-cell technologies have allowed the profiling of tumors at unprecedented depth, which, in combination with newly developed computational tools, enable the dissection of tumor evolution with increasing precision. However, our understanding of mechanisms that regulate intratumoral heterogeneity and our ability to modulate it has been lagging behind. Recent data demonstrate that epigenetic regulators, including histone demethylases, may control the cell-to-cell variability of transcriptomes and chromatin profiles and they may modulate therapeutic responses via this function. Thus, the therapeutic targeting of epigenetic enzymes may be used to decrease intratumoral cellular heterogeneity and treatment resistance, when used in combination with other types of agents.
Collapse
Affiliation(s)
- Kunihiko Hinohara
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Kornelia Polyak
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
67
|
Charlebois DA, Balázsi G. Modeling cell population dynamics. In Silico Biol 2019; 13:21-39. [PMID: 30562900 PMCID: PMC6598210 DOI: 10.3233/isb-180470] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/13/2018] [Accepted: 10/16/2018] [Indexed: 12/27/2022]
Abstract
Quantitative modeling is quickly becoming an integral part of biology, due to the ability of mathematical models and computer simulations to generate insights and predict the behavior of living systems. Single-cell models can be incapable or misleading for inferring population dynamics, as they do not consider the interactions between cells via metabolites or physical contact, nor do they consider competition for limited resources such as nutrients or space. Here we examine methods that are commonly used to model and simulate cell populations. First, we cover simple models where analytic solutions are available, and then move on to more complex scenarios where computational methods are required. Overall, we present a summary of mathematical models used to describe cell population dynamics, which may aid future model development and highlights the importance of population modeling in biology.
Collapse
Affiliation(s)
- Daniel A. Charlebois
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, NY, USA
- Department of Physics, University of Alberta, Edmonton, AB, Canada
| | - Gábor Balázsi
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, NY, USA
- Department of Biomedical Engineering, Stony Brook University, NY, USA
| |
Collapse
|
68
|
Abstract
Quantitative modeling is quickly becoming an integral part of biology, due to the ability of mathematical models and computer simulations to generate insights and predict the behavior of living systems. Single-cell models can be incapable or misleading for inferring population dynamics, as they do not consider the interactions between cells via metabolites or physical contact, nor do they consider competition for limited resources such as nutrients or space. Here we examine methods that are commonly used to model and simulate cell populations. First, we cover simple models where analytic solutions are available, and then move on to more complex scenarios where computational methods are required. Overall, we present a summary of mathematical models used to describe cell population dynamics, which may aid future model development and highlights the importance of population modeling in biology.
Collapse
Affiliation(s)
- Daniel A Charlebois
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, NY, USA.,Department of Physics, University of Alberta, Edmonton, AB, Canada
| | - Gábor Balázsi
- The Louis and Beatrice Laufer Center for Physical and Quantitative Biology, Stony Brook University, NY, USA.,Department of Biomedical Engineering, Stony Brook University, NY, USA
| |
Collapse
|
69
|
Li S, Giardina DM, Siegal ML. Control of nongenetic heterogeneity in growth rate and stress tolerance of Saccharomyces cerevisiae by cyclic AMP-regulated transcription factors. PLoS Genet 2018; 14:e1007744. [PMID: 30388117 PMCID: PMC6241136 DOI: 10.1371/journal.pgen.1007744] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 11/14/2018] [Accepted: 10/05/2018] [Indexed: 01/01/2023] Open
Abstract
Genetically identical cells exhibit extensive phenotypic variation even under constant and benign conditions. This so-called nongenetic heterogeneity has important clinical implications: within tumors and microbial infections, cells show nongenetic heterogeneity in growth rate and in susceptibility to drugs or stress. The budding yeast, Saccharomyces cerevisiae, shows a similar form of nongenetic heterogeneity in which growth rate correlates positively with susceptibility to acute heat stress at the single-cell level. Using genetic and chemical perturbations, combined with high-throughput single-cell assays of yeast growth and gene expression, we show here that heterogeneity in intracellular cyclic AMP (cAMP) levels acting through the conserved Ras/cAMP/protein kinase A (PKA) pathway and its target transcription factors, Msn2 and Msn4, underlies this nongenetic heterogeneity. Lower levels of cAMP correspond to slower growth, as shown by direct comparison of cAMP concentration in subpopulations enriched for slower vs. faster growing cells. Concordantly, an endogenous reporter of this pathway’s activity correlates with growth in individual cells. The paralogs Msn2 and Msn4 differ in their roles in nongenetic heterogeneity in a way that demonstrates slow growth and stress tolerance are not inevitably linked. Heterogeneity in growth rate requires each, whereas only Msn2 is required for heterogeneity in expression of Tsl1, a subunit of trehalose synthase that contributes to acute-stress tolerance. Perturbing nongenetic heterogeneity by mutating genes in this pathway, or by culturing wild-type cells with the cell-permeable cAMP analog 8-bromo-cAMP or the PKA inhibitor H89, significantly impacts survival of acute heat stress. Perturbations that increase intracellular cAMP levels reduce the slower-growing subpopulation and increase susceptibility to acute heat stress, whereas PKA inhibition slows growth and decreases susceptibility to acute heat stress. Loss of Msn2 reduces, but does not completely eliminate, the correlation in individual cells between growth rate and acute-stress survival, suggesting a major role for the Msn2 pathway in nongenetic heterogeneity but also a residual benefit of slow growth. Our results shed light on the genetic control of nongenetic heterogeneity and suggest a possible means of defeating bet-hedging pathogens or tumor cells by making them more uniformly susceptible to treatment. Nongenetic heterogeneity exists when a trait differs among individuals that have identical genotypes and environments. A clonal population can maximize its long-term success in an uncertain environment by diversifying its phenotypes via nongenetic heterogeneity: the currently unfavored ones may become the favored ones when conditions change. Nongenetic heterogeneity has clinical relevance. For example, populations of tumor cells or infectious microbes show cell-to-cell differences in growth and in drug or stress tolerance. This heterogeneity hampers efficient treatment and can potentiate harmful evolution of a tumor or pathogen. We show that in budding yeast, heterogeneity in intracellular cyclic AMP levels acting through the conserved Ras/cAMP/protein kinase A (PKA) pathway and its target transcription factors, Msn2 and Msn4, underlies the nongenetic heterogeneity of both single-cell growth rate and acute heat-stress tolerance. Perturbations of this pathway significantly affect population survival upon acute heat stress. These results illuminate a mechanism of nongenetic heterogeneity and suggest the potential value of antitumor or antifungal treatment strategies that target nongenetic heterogeneity to render the tumor or pathogen population more uniformly susceptible to a second drug that aims to kill.
Collapse
Affiliation(s)
- Shuang Li
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Daniella M. Giardina
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
| | - Mark L. Siegal
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
70
|
Berthelot H, Duhamel S, L'Helguen S, Maguer JF, Wang S, Cetinić I, Cassar N. NanoSIMS single cell analyses reveal the contrasting nitrogen sources for small phytoplankton. ISME JOURNAL 2018; 13:651-662. [PMID: 30323264 DOI: 10.1038/s41396-018-0285-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 07/09/2018] [Accepted: 09/08/2018] [Indexed: 12/16/2022]
Abstract
Nitrogen (N) is a limiting nutrient in vast regions of the world's oceans, yet the sources of N available to various phytoplankton groups remain poorly understood. In this study, we investigated inorganic carbon (C) fixation rates and nitrate (NO3-), ammonium (NH4+) and urea uptake rates at the single cell level in photosynthetic pico-eukaryotes (PPE) and the cyanobacteria Prochlorococcus and Synechococcus. To that end, we used dual 15N and 13C-labeled incubation assays coupled to flow cytometry cell sorting and nanoSIMS analysis on samples collected in the North Pacific Subtropical Gyre (NPSG) and in the California Current System (CCS). Based on these analyses, we found that photosynthetic growth rates (based on C fixation) of PPE were higher in the CCS than in the NSPG, while the opposite was observed for Prochlorococcus. Reduced forms of N (NH4+ and urea) accounted for the majority of N acquisition for all the groups studied. NO3- represented a reduced fraction of total N uptake in all groups but was higher in PPE (17.4 ± 11.2% on average) than in Prochlorococcus and Synechococcus (4.5 ± 6.5 and 2.9 ± 2.1% on average, respectively). This may in part explain the contrasting biogeography of these picoplankton groups. Moreover, single cell analyses reveal that cell-to-cell heterogeneity within picoplankton groups was significantly greater for NO3- uptake than for C fixation and NH4+ uptake. We hypothesize that cellular heterogeneity in NO3- uptake within groups facilitates adaptation to the fluctuating availability of NO3- in the environment.
Collapse
Affiliation(s)
- Hugo Berthelot
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Brest, France.
| | - Solange Duhamel
- Division of Biology and Paleo Environment, Lamont-Doherty Earth Observatory, PO Box 1000, 61 Route 9W, Palisades, NY, 10964, USA
| | - Stéphane L'Helguen
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Brest, France
| | - Jean-Francois Maguer
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Brest, France
| | - Seaver Wang
- Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Ivona Cetinić
- NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Code 616, Greenbelt, MD, USA.,GESTAR/Universities Space Research Association, Columbia, MD, USA
| | - Nicolas Cassar
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Brest, France. .,Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.
| |
Collapse
|
71
|
Phenotypic heterogeneity: a bacterial virulence strategy. Microbes Infect 2018; 20:570-577. [DOI: 10.1016/j.micinf.2018.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 11/21/2022]
|
72
|
Fernández-Niño M, Pulido S, Stefanoska D, Pérez C, González-Ramos D, van Maris AJA, Marchal K, Nevoigt E, Swinnen S. Identification of novel genes involved in acetic acid tolerance of Saccharomyces cerevisiae using pooled-segregant RNA sequencing. FEMS Yeast Res 2018; 18:5097782. [DOI: 10.1093/femsyr/foy100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 09/11/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Miguel Fernández-Niño
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
- Department of Chemical Engineering, Universidad de los Andes, Cra 1 N° 18A - 12, 111711 Bogotá, Colombia
| | - Sergio Pulido
- Department of Plant Biotechnology and Bioinformatics, Department of Information Technology, ID lab, IMEC, Ghent University, Technologiepark 15, 9052 Ghent, Belgium
| | - Despina Stefanoska
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
| | - Camilo Pérez
- Department of Plant Biotechnology and Bioinformatics, Department of Information Technology, ID lab, IMEC, Ghent University, Technologiepark 15, 9052 Ghent, Belgium
| | - Daniel González-Ramos
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Antonius J A van Maris
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Brinellvägen 8, 114 28 Stockholm, Sweden
| | - Kathleen Marchal
- Department of Plant Biotechnology and Bioinformatics, Department of Information Technology, ID lab, IMEC, Ghent University, Technologiepark 15, 9052 Ghent, Belgium
| | - Elke Nevoigt
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
| | - Steve Swinnen
- Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany
| |
Collapse
|
73
|
Schaerli Y, Jiménez A, Duarte JM, Mihajlovic L, Renggli J, Isalan M, Sharpe J, Wagner A. Synthetic circuits reveal how mechanisms of gene regulatory networks constrain evolution. Mol Syst Biol 2018; 14:e8102. [PMID: 30201776 PMCID: PMC6129954 DOI: 10.15252/msb.20178102] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 12/22/2022] Open
Abstract
Phenotypic variation is the raw material of adaptive Darwinian evolution. The phenotypic variation found in organismal development is biased towards certain phenotypes, but the molecular mechanisms behind such biases are still poorly understood. Gene regulatory networks have been proposed as one cause of constrained phenotypic variation. However, most pertinent evidence is theoretical rather than experimental. Here, we study evolutionary biases in two synthetic gene regulatory circuits expressed in Escherichia coli that produce a gene expression stripe-a pivotal pattern in embryonic development. The two parental circuits produce the same phenotype, but create it through different regulatory mechanisms. We show that mutations cause distinct novel phenotypes in the two networks and use a combination of experimental measurements, mathematical modelling and DNA sequencing to understand why mutations bring forth only some but not other novel gene expression phenotypes. Our results reveal that the regulatory mechanisms of networks restrict the possible phenotypic variation upon mutation. Consequently, seemingly equivalent networks can indeed be distinct in how they constrain the outcome of further evolution.
Collapse
Affiliation(s)
- Yolanda Schaerli
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | - Alba Jiménez
- Systems Biology Program, Centre for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
| | - José M Duarte
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | - Ljiljana Mihajlovic
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | | | - Mark Isalan
- Department of Life Sciences, Imperial College London, London, UK
- Imperial College Centre for Synthetic Biology, Imperial College London, London, UK
| | - James Sharpe
- Systems Biology Program, Centre for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
- Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona, Spain
- EMBL Barcelona European Molecular Biology Laboratory, Barcelona, Spain
| | - Andreas Wagner
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
- The Swiss Institute of Bioinformatics, Lausanne, Switzerland
- The Santa Fe Institute, Santa Fe, NM, USA
| |
Collapse
|
74
|
Emri T, Antal K, Riley R, Karányi Z, Miskei M, Orosz E, Baker S, Wiebenga A, de Vries R, Pócsi I. Duplications and losses of genes encoding known elements of the stress defence system of the Aspergilli contribute to the evolution of these filamentous fungi but do not directly influence their environmental stress tolerance. Stud Mycol 2018; 91:23-36. [PMID: 30425415 PMCID: PMC6231086 DOI: 10.1016/j.simyco.2018.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The contribution of stress protein duplication and deletion events to the evolution of the Aspergilli was studied. We performed a large-scale homology analysis of stress proteins and generated and analysed three stress defence system models based on Saccharomyces cerevisiae, Schizosaccharomyces pombe and Aspergillus nidulans. Although both yeast-based and A. nidulans-based models were suitable to trace evolutionary changes, the A. nidulans-based model performed better in mapping stress protein radiations. The strong Mantel correlation found between the positions of species in the phylogenetic tree on the one hand and either in the A. nidulans-based or S. cerevisiae-based models on the other hand demonstrated that stress protein expansions and reductions contributed significantly to the evolution of the Aspergilli. Interestingly, stress tolerance attributes correlated well with the number of orthologs only for a few stress proteins. Notable examples are Ftr1 iron permease and Fet3 ferro-O2-oxidoreductase, elements of the reductive iron assimilation pathway, in the S. cerevisiae-based model, as well as MpkC, a HogA-like mitogen activated protein kinase in the A. nidulans-based model. In the case of the iron assimilation proteins, the number of orthologs showed a positive correlation with H2O2-induced stress tolerance while the number of MpkC orthologs correlated positively with Congo Red induced cell wall stress, sorbitol induced osmotic stress and H2O2 induced oxidative stress tolerances. For most stress proteins, changes in the number of orthologs did not correlate well with any stress tolerance attributes. As a consequence, stress tolerance patterns of the studied Aspergilli did not correlate with either the sets of stress response proteins in general or with the phylogeny of the species studied. These observations suggest that stress protein duplication and deletion events significantly contributed to the evolution of stress tolerance attributes of Aspergilli. In contrast, there are other processes, which may counterbalance the effects of stress gene duplications or deletions including (i) alterations in the structures of stress proteins leading to changes in their biological activities, (ii) varying biosynthesis of stress proteins, (iii) rewiring stress response regulatory networks or even (iv) acquiring new stress response genes by horizontal gene transfer. All these multilevel changes are indispensable for the successful adaptation of filamentous fungi to altering environmental conditions, especially when these organisms are entering new ecological niches.
Collapse
Affiliation(s)
- T. Emri
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
| | - K. Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly University, Eszterházy tér 1., H-3300, Eger, Hungary
| | - R. Riley
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Z. Karányi
- Department of Medicine, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
| | - M. Miskei
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
- MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
| | - E. Orosz
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
| | - S.E. Baker
- Environmental Molecular Sciences Division, Earth and Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, 99352, USA
| | - A. Wiebenga
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
- Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - R.P. de Vries
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
- Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - I. Pócsi
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
| |
Collapse
|
75
|
Van den Bergh B, Swings T, Fauvart M, Michiels J. Experimental Design, Population Dynamics, and Diversity in Microbial Experimental Evolution. Microbiol Mol Biol Rev 2018; 82:e00008-18. [PMID: 30045954 PMCID: PMC6094045 DOI: 10.1128/mmbr.00008-18] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In experimental evolution, laboratory-controlled conditions select for the adaptation of species, which can be monitored in real time. Despite the current popularity of such experiments, nature's most pervasive biological force was long believed to be observable only on time scales that transcend a researcher's life-span, and studying evolution by natural selection was therefore carried out solely by comparative means. Eventually, microorganisms' propensity for fast evolutionary changes proved us wrong, displaying strong evolutionary adaptations over a limited time, nowadays massively exploited in laboratory evolution experiments. Here, we formulate a guide to experimental evolution with microorganisms, explaining experimental design and discussing evolutionary dynamics and outcomes and how it is used to assess ecoevolutionary theories, improve industrially important traits, and untangle complex phenotypes. Specifically, we give a comprehensive overview of the setups used in experimental evolution. Additionally, we address population dynamics and genetic or phenotypic diversity during evolution experiments and expand upon contributing factors, such as epistasis and the consequences of (a)sexual reproduction. Dynamics and outcomes of evolution are most profoundly affected by the spatiotemporal nature of the selective environment, where changing environments might lead to generalists and structured environments could foster diversity, aided by, for example, clonal interference and negative frequency-dependent selection. We conclude with future perspectives, with an emphasis on possibilities offered by fast-paced technological progress. This work is meant to serve as an introduction to those new to the field of experimental evolution, as a guide to the budding experimentalist, and as a reference work to the seasoned expert.
Collapse
Affiliation(s)
- Bram Van den Bergh
- Laboratory of Symbiotic and Pathogenic Interactions, Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, Leuven, Belgium
- Michiels Lab, Center for Microbiology, VIB, Leuven, Belgium
- Douglas Lab, Department of Entomology, Cornell University, Ithaca, New York, USA
| | - Toon Swings
- Laboratory of Symbiotic and Pathogenic Interactions, Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, Leuven, Belgium
- Michiels Lab, Center for Microbiology, VIB, Leuven, Belgium
| | - Maarten Fauvart
- Laboratory of Symbiotic and Pathogenic Interactions, Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, Leuven, Belgium
- Michiels Lab, Center for Microbiology, VIB, Leuven, Belgium
- imec, Leuven, Belgium
| | - Jan Michiels
- Laboratory of Symbiotic and Pathogenic Interactions, Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, Leuven, Belgium
- Michiels Lab, Center for Microbiology, VIB, Leuven, Belgium
| |
Collapse
|
76
|
Scott LH, Mathews JC, Flematti GR, Filipovska A, Rackham O. An Artificial Yeast Genetic Circuit Enables Deep Mutational Scanning of an Antimicrobial Resistance Protein. ACS Synth Biol 2018; 7:1907-1917. [PMID: 29979580 DOI: 10.1021/acssynbio.8b00121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the molecular mechanisms underlying antibiotic resistance requires concerted efforts in enzymology and medicinal chemistry. Here we describe a new synthetic biology approach to antibiotic development, where the presence of tetracycline antibiotics is linked to a life-death selection in Saccharomyces cerevisiae. This artificial genetic circuit allowed the deep mutational scanning of the tetracycline inactivating enzyme TetX, revealing key functional residues. We used both positive and negative selections to confirm the importance of different residues for TetX activity, and profiled activity hotspots for different tetracyclines to reveal substrate-specific activity determinants. We found that precise positioning of FAD and hydrophobic shielding of the tetracycline are critical for enzymatic inactivation of doxycycline. However, positioning of FAD is suboptimal in the case of anhydrotetracycline, potentially explaining its comparatively poor degradation and potential as an inhibitor for this family of enzymes. By combining artificial genetic circuits whose function can be modulated by antimicrobial resistance determinants, we establish a framework to select for the next generation of antibiotics.
Collapse
Affiliation(s)
- Louis H. Scott
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands 6009, Australia
| | - James C. Mathews
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands 6009, Australia
| | - Gavin R. Flematti
- School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands 6009, Australia
- School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands 6009, Australia
- School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| |
Collapse
|
77
|
Smith A, Kaczmar A, Bamford RA, Smith C, Frustaci S, Kovacs-Simon A, O'Neill P, Moore K, Paszkiewicz K, Titball RW, Pagliara S. The Culture Environment Influences Both Gene Regulation and Phenotypic Heterogeneity in Escherichia coli. Front Microbiol 2018; 9:1739. [PMID: 30158905 PMCID: PMC6104134 DOI: 10.3389/fmicb.2018.01739] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 07/11/2018] [Indexed: 11/13/2022] Open
Abstract
Microorganisms shape the composition of the medium they are growing in, which in turn has profound consequences on the reprogramming of the population gene-expression profile. In this paper, we investigate the progressive changes in pH and sugar availability in the medium of a growing Escherichia coli (E. coli) culture. We show how these changes have an effect on both the cellular heterogeneity within the microbial community and the gene-expression profile of the microbial population. We measure the changes in gene-expression as E. coli moves from lag, to exponential, and finally into stationary phase. We found that pathways linked to the changes in the medium composition such as ribosomal, tricarboxylic acid cycle (TCA), transport, and metabolism pathways are strongly regulated during the different growth phases. In order to quantify the corresponding temporal changes in the population heterogeneity, we measure the fraction of E. coli persisters surviving different antibiotic treatments during the various phases of growth. We show that the composition of the medium in which β-lactams or quinolones, but not aminoglycosides, are dissolved strongly affects the measured phenotypic heterogeneity within the culture. Our findings contribute to a better understanding on how the composition of the culture medium influences both the reprogramming in the population gene-expression and the emergence of phenotypic variants.
Collapse
Affiliation(s)
- Ashley Smith
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | - Agnieszka Kaczmar
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | - Rosemary A Bamford
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| | | | - Simona Frustaci
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | | | - Paul O'Neill
- Biosciences, University of Exeter, Exeter, United Kingdom
| | - Karen Moore
- Biosciences, University of Exeter, Exeter, United Kingdom
| | | | | | - Stefano Pagliara
- Living Systems Institute, University of Exeter, Exeter, United Kingdom.,Biosciences, University of Exeter, Exeter, United Kingdom
| |
Collapse
|
78
|
Rouzeau C, Dagkesamanskaya A, Langer K, Bibette J, Baudry J, Pompon D, Anton-Leberre V. Adaptive response of yeast cells to triggered toxicity of phosphoribulokinase. Res Microbiol 2018; 169:335-342. [PMID: 29964131 DOI: 10.1016/j.resmic.2018.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/15/2018] [Accepted: 06/20/2018] [Indexed: 11/26/2022]
Abstract
Adjustment of plasmid copy number resulting from the balance between positive and negative impacts of borne synthetic genes, plays a critical role in the global efficiency of multistep metabolic engineering. Differential expression of co-expressed engineered genes is frequently observed depending on growth phases, metabolic status and triggered adjustments of plasmid copy numbers, constituting a dynamic process contributing to minimize global engineering burden. A yeast model involving plasmid based expression of phosphoribulokinase (PRKp), a key enzyme for the reconstruction of synthetic Calvin cycle, was designed to gain further insights into such a mechanism. A conditional PRK expression cassette was cloned either onto a low (ARS-CEN based) or a high (2-micron origin based) copy number plasmid using complementation of a trp1 genomic mutation as constant positive selection. Evolution of plasmid copy numbers, PRKp expressions, and cell growth rates were dynamically monitored following gene de-repression through external doxycycline concentration shifts. In the absence of RubisCO encoding gene permitting metabolic recycling, PRKp expression that led to depletion of ribulose phosphate, a critical metabolite for aromatic amino-acids biosynthesis, and accumulation of the dead-end diphosphate product contribute to toxicity. Triggered copy number adjustment was found to be a dynamic process depending both on plasmid types and levels of PRK induction. With the ARS-CEN plasmid, cell growth was abruptly affected only when level PRKp expression exceeded a threshold value. In contrast, a proportional relationship was observed with the 2-micron plasmid consistent with large copy number adjustments. Micro-compartment partitioning of bulk cultures by embedding individual cells into inverse culture medium/oil droplets, revealed the presence of slow and fast growing subpopulations that differ in relative proportions for low and high copy number plasmids.
Collapse
Affiliation(s)
| | | | - Krzysztof Langer
- Laboratoire Colloïdes et Matériaux Divisés, From the Institute of Chemistry, Biology and Innovation (CBI), ESPCI ParisTech, CNRS, UMR 8231, PSL Research University, 10 rue Vauquelin, 75005, Paris, France
| | - Jérôme Bibette
- Laboratoire Colloïdes et Matériaux Divisés, From the Institute of Chemistry, Biology and Innovation (CBI), ESPCI ParisTech, CNRS, UMR 8231, PSL Research University, 10 rue Vauquelin, 75005, Paris, France
| | - Jean Baudry
- Laboratoire Colloïdes et Matériaux Divisés, From the Institute of Chemistry, Biology and Innovation (CBI), ESPCI ParisTech, CNRS, UMR 8231, PSL Research University, 10 rue Vauquelin, 75005, Paris, France
| | - Denis Pompon
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | | |
Collapse
|
79
|
Morgan MD, Marioni JC. CpG island composition differences are a source of gene expression noise indicative of promoter responsiveness. Genome Biol 2018; 19:81. [PMID: 29945659 PMCID: PMC6020341 DOI: 10.1186/s13059-018-1461-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/04/2018] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Population phenotypic variation can arise from genetic differences between individuals, or from cellular heterogeneity in an isogenic group of cells or organisms. The emergence of gene expression differences between genetically identical cells is referred to as gene expression noise, the sources of which are not well understood. RESULTS In this work, by studying gene expression noise between multiple cell lineages and mammalian species, we find consistent evidence of a role for CpG islands as sources of gene expression noise. Variation in noise among CpG island promoters can be partially attributed to differences in island size, in which short islands have noisier gene expression. Building on these findings, we investigate the potential for short CpG islands to act as fast response elements to environmental stimuli. Specifically, we find that these islands are enriched amongst primary response genes in SWI/SNF-independent stimuli, suggesting that expression noise is an indicator of promoter responsiveness. CONCLUSIONS Thus, through the integration of single-cell RNA expression profiling, chromatin landscape and temporal gene expression dynamics, we have uncovered a role for short CpG island promoters as fast response elements.
Collapse
Affiliation(s)
- Michael D Morgan
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
| | - John C Marioni
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Li Ka Shing Centre, Cambridge, CB2 0RE, UK.
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK.
| |
Collapse
|
80
|
Singh M, Warita K, Warita T, Faeder JR, Lee REC, Sant S, Oltvai ZN. Shift from stochastic to spatially-ordered expression of serine-glycine synthesis enzymes in 3D microtumors. Sci Rep 2018; 8:9388. [PMID: 29925909 PMCID: PMC6010463 DOI: 10.1038/s41598-018-27266-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 05/25/2018] [Indexed: 12/15/2022] Open
Abstract
Cell-to-cell differences in protein expression in normal tissues and tumors are a common phenomenon, but the underlying principles that govern this heterogeneity are largely unknown. Here, we show that in monolayer cancer cell-line cultures, the expression of the five metabolic enzymes of serine-glycine synthesis (SGS), including its rate-limiting enzyme, phosphoglycerate dehydrogenase (PHGDH), displays stochastic cell-to-cell variation. By contrast, in cancer cell line-derived three-dimensional (3D) microtumors PHGDH expression is restricted to the outermost part of the microtumors' outer proliferative cell layer, while the four other SGS enzymes display near uniform expression throughout the microtumor. A mathematical model suggests that metabolic stress in the microtumor core activates factors that restrict PHGDH expression. Thus, intracellular enzyme expression in growing cell ecosystems can shift to spatially ordered patterns in 3D structured environments due to emergent cell-cell communication, with potential implications for the design of effective anti-metabolic cancer therapies.
Collapse
Affiliation(s)
- Manjulata Singh
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Katsuhiko Warita
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Tomoko Warita
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - James R Faeder
- Department of Computational & Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Robin E C Lee
- Department of Computational & Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| | - Shilpa Sant
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
- Department of Bioengineering, Swanson School of Engineering, McGowan Institute for Regenerative Medicine, and UPMC-Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
| | - Zoltán N Oltvai
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
- Department of Computational & Systems Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| |
Collapse
|
81
|
Draghi J. Links between evolutionary processes and phenotypic robustness in microbes. Semin Cell Dev Biol 2018; 88:46-53. [PMID: 29803630 DOI: 10.1016/j.semcdb.2018.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/16/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022]
Abstract
The costs and benefits of random phenotypic heterogeneity in microbes have been vigorously debated and experimental tested for decades; yet, this conversation is largely independent from discussion of phenotypic robustness in other disciplines. In this review I connect microbial examples of stochasticity with studies on the ecological and population-genetic consequences of phenotypic variability. These topics illustrate the complexity of selection pressures on phenotypic robustness and provide inspiration that this complexity can be parsed with theoretical advances and the experimental power of microbial systems.
Collapse
Affiliation(s)
- Jeremy Draghi
- Department of Biology, Brooklyn College, The Graduate Center, City University of New York, United States.
| |
Collapse
|
82
|
Lázár V, Martins A, Spohn R, Daruka L, Grézal G, Fekete G, Számel M, Jangir PK, Kintses B, Csörgő B, Nyerges Á, Györkei Á, Kincses A, Dér A, Walter FR, Deli MA, Urbán E, Hegedűs Z, Olajos G, Méhi O, Bálint B, Nagy I, Martinek TA, Papp B, Pál C. Antibiotic-resistant bacteria show widespread collateral sensitivity to antimicrobial peptides. Nat Microbiol 2018; 3:718-731. [PMID: 29795541 DOI: 10.1038/s41564-018-0164-0] [Citation(s) in RCA: 236] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 04/17/2018] [Indexed: 01/28/2023]
Abstract
Antimicrobial peptides are promising alternative antimicrobial agents. However, little is known about whether resistance to small-molecule antibiotics leads to cross-resistance (decreased sensitivity) or collateral sensitivity (increased sensitivity) to antimicrobial peptides. We systematically addressed this question by studying the susceptibilities of a comprehensive set of 60 antibiotic-resistant Escherichia coli strains towards 24 antimicrobial peptides. Strikingly, antibiotic-resistant bacteria show a high frequency of collateral sensitivity to antimicrobial peptides, whereas cross-resistance is relatively rare. We identify clinically relevant multidrug-resistance mutations that increase bacterial sensitivity to antimicrobial peptides. Collateral sensitivity in multidrug-resistant bacteria arises partly through regulatory changes shaping the lipopolysaccharide composition of the bacterial outer membrane. These advances allow the identification of antimicrobial peptide-antibiotic combinations that enhance antibiotic activity against multidrug-resistant bacteria and slow down de novo evolution of resistance. In particular, when co-administered as an adjuvant, the antimicrobial peptide glycine-leucine-amide caused up to 30-fold decrease in the antibiotic resistance level of resistant bacteria. Our work provides guidelines for the development of efficient peptide-based therapies of antibiotic-resistant infections.
Collapse
Affiliation(s)
- Viktória Lázár
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ana Martins
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Réka Spohn
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Lejla Daruka
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Gábor Grézal
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Gergely Fekete
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mónika Számel
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Pramod K Jangir
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Bálint Kintses
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Bálint Csörgő
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ákos Nyerges
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ádám Györkei
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Kincses
- Biomolecular Electronics Research Group, Bionanoscience Unit, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Dér
- Biomolecular Electronics Research Group, Bionanoscience Unit, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Fruzsina R Walter
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mária A Deli
- Biological Barriers Research Group, Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Edit Urbán
- Institute of Clinical Microbiology, Albert Szent-Györgyi Medical and Pharmaceutical Center, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zsófia Hegedűs
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Gábor Olajos
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Orsolya Méhi
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | | | - István Nagy
- SeqOmics Biotechnology Ltd, Mórahalom, Hungary.,Sequencing Platform, Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Tamás A Martinek
- Institute of Pharmaceutical Analysis, University of Szeged, Szeged, Hungary
| | - Balázs Papp
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
| | - Csaba Pál
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
| |
Collapse
|
83
|
Waite AJ, Frankel NW, Emonet T. Behavioral Variability and Phenotypic Diversity in Bacterial Chemotaxis. Annu Rev Biophys 2018; 47:595-616. [PMID: 29618219 DOI: 10.1146/annurev-biophys-062215-010954] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Living cells detect and process external signals using signaling pathways that are affected by random fluctuations. These variations cause the behavior of individual cells to fluctuate over time (behavioral variability) and generate phenotypic differences between genetically identical individuals (phenotypic diversity). These two noise sources reduce our ability to predict biological behavior because they diversify cellular responses to identical signals. Here, we review recent experimental and theoretical advances in understanding the mechanistic origin and functional consequences of such variation in Escherichia coli chemotaxis-a well-understood model of signal transduction and behavior. After briefly summarizing the architecture and logic of the chemotaxis system, we discuss determinants of behavior and chemotactic performance of individual cells. Then, we review how cell-to-cell differences in protein abundance map onto differences in individual chemotactic abilities and how phenotypic variability affects the performance of the population. We conclude with open questions to be addressed by future research.
Collapse
Affiliation(s)
- Adam James Waite
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520; .,Current affiliation: Calico Life Sciences, LLC, South San Francisco, California 94080
| | - Nicholas W Frankel
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520; .,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158
| | - Thierry Emonet
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520; .,Department of Physics, Yale University, New Haven, Connecticut 06520
| |
Collapse
|
84
|
Abstract
Many single-cell observables are highly heterogeneous. A part of this heterogeneity stems from age-related phenomena: the fact that there is a nonuniform distribution of cells with different ages. This has led to a renewed interest in analytic methodologies including use of the 'von Foerster equation' for predicting population growth and cell age distributions. Here we discuss how some of the most popular implementations of this machinery assume a strong condition on the ergodicity of the cell cycle duration ensemble. We show that one common definition for the term ergodicity, 'a single individual observed over many generations recapitulates the behavior of the entire ensemble' is implied by the other, 'the probability of observing any state is conserved across time and over all individuals' in an ensemble with a fixed number of individuals but that this is not true when the ensemble is growing. We further explore the impact of generational correlations between cell cycle durations on the population growth rate. Finally, we explore the 'growth rate gain'-the phenomenon that variations in the cell cycle duration leads to an improved population-level growth rate-in this context. We highlight that, fundamentally, this effect is due to asymmetric division.
Collapse
Affiliation(s)
- Nash D Rochman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | | | | |
Collapse
|
85
|
The emergence of metabolic heterogeneity and diverse growth responses in isogenic bacterial cells. ISME JOURNAL 2018; 12:1199-1209. [PMID: 29335635 DOI: 10.1038/s41396-017-0036-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/28/2017] [Accepted: 12/03/2017] [Indexed: 11/08/2022]
Abstract
Microorganisms adapt to frequent environmental changes through population diversification. Previous studies demonstrated phenotypic diversity in a clonal population and its important effects on microbial ecology. However, the dynamic changes of phenotypic composition have rarely been characterized. Also, cellular variations and environmental factors responsible for phenotypic diversity remain poorly understood. Here, we studied phenotypic diversity driven by metabolic heterogeneity. We characterized metabolic activities and growth kinetics of starved Escherichia coli cells subject to nutrient upshift at single-cell resolution. We observed three subpopulations with distinct metabolic activities and growth phenotypes. One subpopulation was metabolically active and immediately grew upon nutrient upshift. One subpopulation was metabolically inactive and non-viable. The other subpopulation was metabolically partially active, and did not grow upon nutrient upshift. The ratio of these subpopulations changed dynamically during starvation. A long-term observation of cells with partial metabolic activities indicated that their metabolism was later spontaneously restored, leading to growth recovery. Further investigations showed that oxidative stress can induce the emergence of a subpopulation with partial metabolic activities. Our findings reveal the emergence of metabolic heterogeneity and associated dynamic changes in phenotypic composition. In addition, the results shed new light on microbial dormancy, which has important implications in microbial ecology and biomedicine.
Collapse
|
86
|
Ecker S, Pancaldi V, Valencia A, Beck S, Paul DS. Epigenetic and Transcriptional Variability Shape Phenotypic Plasticity. Bioessays 2017; 40. [PMID: 29251357 DOI: 10.1002/bies.201700148] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/31/2017] [Indexed: 12/15/2022]
Abstract
Epigenetic and transcriptional variability contribute to the vast diversity of cellular and organismal phenotypes and are key in human health and disease. In this review, we describe different types, sources, and determinants of epigenetic and transcriptional variability, enabling cells and organisms to adapt and evolve to a changing environment. We highlight the latest research and hypotheses on how chromatin structure and the epigenome influence gene expression variability. Further, we provide an overview of challenges in the analysis of biological variability. An improved understanding of the molecular mechanisms underlying epigenetic and transcriptional variability, at both the intra- and inter-individual level, provides great opportunity for disease prevention, better therapeutic approaches, and personalized medicine.
Collapse
Affiliation(s)
- Simone Ecker
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6BT, UK
| | - Vera Pancaldi
- Barcelona Supercomputing Center (BSC), C/ Jordi Girona 39-31, 08034, Barcelona, Spain
| | - Alfonso Valencia
- Barcelona Supercomputing Center (BSC), C/ Jordi Girona 39-31, 08034, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - Stephan Beck
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6BT, UK
| | - Dirk S Paul
- MRC/BHF Cardiovascular Epidemiology Unit Department of Public Health and Primary Care, University of Cambridge, Cambridge, CB1 8RN, UK.,Department of Human Genetics Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1HH, UK
| |
Collapse
|
87
|
Impact of Morphological Sectors on Antifungal Susceptibility Testing and Virulence Studies. Antimicrob Agents Chemother 2017; 61:AAC.00755-17. [PMID: 28993330 DOI: 10.1128/aac.00755-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 09/30/2017] [Indexed: 12/11/2022] Open
Abstract
Morphological heterogeneity of Aspergillus terreus cultures was observed during continued cultivation of amphotericin B (AMB)-resistant isolates on drug-free medium. Outgrowth leads to the emergence of multiple sectors that might result from increased growth rates at drug-free conditions. We evaluated the differences in AMB susceptibility and virulence between sector subcultures (ATSec), AMB-resistant (ATR) strains, and AMB-susceptible (ATS) strains. By comparing A. terreus AMB-resistant (ATR) strains and A. terreus sector (ATSec) cultures we observed a highly significant reduction of AMB MICs in ATSec (ATR MIC, 2 to 32 μg/ml; ATSec MIC, 0.12 to 5 μg/ml). Furthermore, Galleria mellonella survival studies revealed an enhanced virulence of ATSec, which was comparable with that of AMB-sensitive Aspergillus terreus strains (median survival rates for ATS isolates, 72 h; for ATSec isolate ATSecG1, 84 h; for ATR isolates, 144 h). Our findings clearly demonstrate that spontaneous culture degeneration occurs in A. terreus and, most importantly, crucially impacts drug efficacy and virulence.
Collapse
|
88
|
Bidnenko E, Bidnenko V. Transcription termination factor Rho and microbial phenotypic heterogeneity. Curr Genet 2017; 64:541-546. [PMID: 29094196 DOI: 10.1007/s00294-017-0775-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 10/27/2017] [Accepted: 10/28/2017] [Indexed: 12/21/2022]
Abstract
Populations of genetically identical microorganisms exhibit high degree of cell-to-cell phenotypic diversity even when grown in uniform environmental conditions. Heterogeneity is a genetically determined trait, which ensures bacterial adaptation and survival in the ever changing environmental conditions. Fluctuations in gene expression (noise) at the level of transcription initiation largely contribute to cell-to-cell variability within population. Not surprisingly, the analyses of the mechanisms driving phenotypic heterogeneity are mainly focused on the activity of promoters and transcriptional factors. Less attention is currently given to a role of intrinsic and factor-dependent transcription terminators. Here, we discuss recent advances in understanding the regulatory role of the multi-functional transcription termination factor Rho, the major inhibitor of pervasive transcription in bacteria and the emerging global regulator of gene expression. We propose that termination activity of Rho might be among the mechanisms by which cells manage the intensity of transcriptional noise, thus affecting population heterogeneity.
Collapse
Affiliation(s)
- Elena Bidnenko
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
| | - Vladimir Bidnenko
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| |
Collapse
|
89
|
Pelechano V. From transcriptional complexity to cellular phenotypes: Lessons from yeast. Yeast 2017; 34:475-482. [PMID: 28866863 DOI: 10.1002/yea.3277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022] Open
Abstract
Pervasive transcription has been reported in many eukaryotic organisms, revealing a highly interleaved transcriptome organization that involves thousands of coding and non-coding RNAs. However, to date, the biological impact of transcriptome complexity is still poorly understood. Here I will review how subtle variations of the transcriptome can lead to divergent cellular phenotypes by fine-tuning both its coding potential and regulation. I will discuss strategies that can be used to link molecular variations with divergent biological outcomes. Finally, I will explore the implication of transcriptional complexity for our understanding of gene expression in the context of cell-to-cell phenotypic variability. Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, P-Box 1031, 171 21, Solna, Sweden
| |
Collapse
|
90
|
Bódi Z, Farkas Z, Nevozhay D, Kalapis D, Lázár V, Csörgő B, Nyerges Á, Szamecz B, Fekete G, Papp B, Araújo H, Oliveira JL, Moura G, Santos MAS, Székely T, Balázsi G, Pál C. Correction: Phenotypic heterogeneity promotes adaptive evolution. PLoS Biol 2017. [PMID: 28632738 PMCID: PMC5478090 DOI: 10.1371/journal.pbio.1002607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|