scholarly journals Characterization and complementation of pMB1 copy number mutant: effect of RNA I gene dosage on plasmid copy number and incompatibility.

1983 ◽  
Vol 154 (2) ◽  
pp. 809-818 ◽  
Author(s):  
D R Moser ◽  
J L Campbell
Keyword(s):  
Copy Number ◽  
Gene Dosage ◽  
Plasmid Copy Number ◽  
Plasmid Copy ◽  
Mutant Effect ◽  
Rna I ◽  
I Gene

scholarly journals Spatiotemporal Variations in Growth Rate and Virulence Plasmid Copy Number during Yersinia pseudotuberculosis Infection

2021 ◽  
Author(s):  
Stephan Schneiders ◽  
Tifaine Hechard ◽  
Tomas Edgren ◽  
Kemal Avican ◽  
Maria Fällman ◽  
...  
Keyword(s):  
Growth Rates ◽  
Copy Number ◽  
Yersinia Pseudotuberculosis ◽  
Gene Dosage ◽  
Growth Dynamics ◽  
Digital Pcr ◽  
Plasmid Copy Number ◽  
Virulence Plasmid ◽  
Mesenteric Lymph Nodes ◽  
Plasmid Copy

Pathogenic Yersinia spp. depend on the activity of a potent virulence plasmid-encoded ysc/yop type 3 secretion system (T3SS) to colonize hosts and cause disease. It was recently shown that Y. pseudotuberculosis up-regulates the virulence plasmid copy number (PCN) during infection and the resulting elevated gene dose of plasmid-encoded T3SS genes is essential for virulence. When and how this novel regulatory mechanism is deployed and regulates the replication of the virulence plasmid during infection is unknown. In the current study, we applied droplet digital PCR (ddPCR) to investigate the dynamics of Y. pseudotuberculosis virulence PCN variations and growth rates in infected mouse organs. We demonstrated that both PCN and growth varied in different tissues and over time throughout the course of infection, indicating that the bacteria adapted to discrete microenvironments during infection. The PCN was highest in Peyer’s Patches and caecum during the clonal invasive phase of the infection, while the fastest growth rates were found in the draining mesenteric lymph nodes. In deeper, systemic organs, the PCN was lower and more modest growth rates were recorded. Our study indicates that increased gene dosage of the plasmid-encoded T3SS genes is most important early in the infection during invasion of the host. The described ddPCR approach will greatly simplify analyses of PCN, growth dynamics, and bacterial loads in infected tissues, and will be readily applicable to other infection models.

scholarly journals Evolutionary Rescue and Drug Resistance on Multicopy Plasmids

Genetics ◽  
2020 ◽  
Vol 215 (3) ◽  
pp. 847-868
Author(s):  
Mario Santer ◽  
Hildegard Uecker
Keyword(s):  
Copy Number ◽  
Gene Dosage ◽  
Branching Processes ◽  
Plasmid Copy Number ◽  
Wild Type ◽  
Plasmid Copy ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Evolutionary Rescue ◽  
Establishment Probability

Bacteria often carry “extra DNA” in the form of plasmids in addition to their chromosome. Many plasmids have a copy number greater than one such that the genes encoded on these plasmids are present in multiple copies per cell. This has evolutionary consequences by increasing the mutational target size, by prompting the (transitory) co-occurrence of mutant and wild-type alleles within the same cell, and by allowing for gene dosage effects. We develop and analyze a mathematical model for bacterial adaptation to harsh environmental change if adaptation is driven by beneficial alleles on multicopy plasmids. Successful adaptation depends on the availability of advantageous alleles and on their establishment probability. The establishment process involves the segregation of mutant and wild-type plasmids to the two daughter cells, allowing for the emergence of mutant homozygous cells over the course of several generations. To model this process, we use the theory of multitype branching processes, where a type is defined by the genetic composition of the cell. Both factors—the availability of advantageous alleles and their establishment probability—depend on the plasmid copy number, and they often do so antagonistically. We find that in the interplay of various effects, a lower or higher copy number may maximize the probability of evolutionary rescue. The decisive factor is the dominance relationship between mutant and wild-type plasmids and potential gene dosage effects. Results from a simple model of antibiotic degradation indicate that the optimal plasmid copy number may depend on the specific environment encountered by the population.

scholarly journals Evolutionary rescue and drug resistance on multicopy plasmids

2019 ◽  
Author(s):  
Mario Santer ◽  
Hildegard Uecker
Keyword(s):  
Copy Number ◽  
Gene Dosage ◽  
Branching Processes ◽  
Plasmid Copy Number ◽  
Wild Type ◽  
Plasmid Copy ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Evolutionary Rescue ◽  
Establishment Probability

AbstractBacteria often carry “extra DNA” in form of plasmids in addition to their chromosome. Many plasmids have a copy number greater than one such that the genes encoded on these plasmids are present in multiple copies per cell. This has evolutionary consequences by increasing the mutational target size, by prompting the (transitory) co-occurrence of mutant and wild-type alleles within the same cell, and by allowing for gene dosage effects. We develop and analyze a mathematical model for bacterial adaptation to harsh environmental change if adaptation is driven by beneficial alleles on multicopy plasmids. Successful adaptation depends on the availability of advantageous alleles and on their establishment probability. The establishment process involves the segregation of mutant and wild-type plasmids to the two daughter cells, allowing for the emergence of mutant-homozygous cells over the course of several generations. To model this process, we use the theory of multi-type branching processes, where a type is defined by the genetic composition of the cell. Both factors – the number of adaptive alleles and their establishment probability – depend on the plasmid copy number, and they often do so antagonistically. We find that in the interplay of various effects, a lower or higher copy number may maximize the probability of evolutionary rescue. The decisive factor is the dominance relationship between mutant and wild-type plasmids and potential gene dosage effects. Results from a simple model of antibiotic degradation indicate that the optimal plasmid copy number may depend on the specific environment encountered by the population.

scholarly journals Segregational Drift and the Interplay between Plasmid Copy Number and Evolvability

2018 ◽  
Vol 36 (3) ◽  
pp. 472-486 ◽  
Author(s):  
Judith Ilhan ◽  
Anne Kupczok ◽  
Christian Woehle ◽  
Tanita Wein ◽  
Nils F Hülter ◽  
...  
Keyword(s):  
Copy Number ◽  
Plasmid Copy Number ◽  
Plasmid Copy

scholarly journals Plasmid copy number noise in monoclonal populations of bacteria

2010 ◽  
Vol 81 (1) ◽  
Author(s):  
Jérôme Wong Ng ◽  
Didier Chatenay ◽  
Jérôme Robert ◽  
Michael Guy Poirier
Keyword(s):  
Copy Number ◽  
Plasmid Copy Number ◽  
Plasmid Copy

scholarly journals Effects of Biofilm Growth on Plasmid Copy Number and Expression of Antibiotic Resistance Genes in Enterococcus faecalis

2013 ◽  
Vol 57 (4) ◽  
pp. 1850-1856 ◽  
Author(s):  
L. C. Cook ◽  
G. M. Dunny
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Resistance Genes ◽  
Copy Number ◽  
Antibiotic Resistance Genes ◽  
Plasmid Copy Number ◽  
Plasmid Copy ◽  
Rapid Reduction ◽  
Biofilm Growth ◽  
Content Type

ABSTRACTBiofilm growth causes increased average plasmid copy number as well as increased copy number heterogeneity inEnterococcus faecaliscells carrying plasmid pCF10. In this study, we examined whether biofilm growth affected the copy number and expression of antibiotic resistance determinants for several plasmids with diverse replication systems. Four differentE. faecalisplasmids, unrelated to pCF10, demonstrated increased copy number in biofilm cells. In biofilm cells, we also observed increased transcription of antibiotic resistance genes present on these plasmids. The increase in plasmid copy number correlated with increased plating efficiency on high concentrations of antibiotics. Single-cell analysis of strains carrying two different plasmids suggested that the increase in plasmid copy number associated with biofilm growth was restricted to a subpopulation of biofilm cells. Regrowth of harvested biofilm cells in liquid culture resulted in a rapid reduction of plasmid copy number to that observed in the planktonic state. These results suggest a possible mechanism by which biofilm growth could reduce susceptibility to antibiotics in clinical settings.

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