scholarly journals Time-Lapse Photomicrography of Lashing, Flexing, and Snapping Movements in Escherichia coli and Corynebacterium Microcultures

1965 ◽  
Vol 90 (3) ◽  
pp. 789-795 ◽  
Author(s):  
Heiner Hoffman ◽  
Michael E. Frank
Keyword(s):  
Escherichia Coli ◽  
Time Lapse ◽  
Time Lapse Photomicrography

Conidium ontogeny in hyphomycetes. The meristem arthrospores of Wallemia sebi

1973 ◽  
Vol 51 (9) ◽  
pp. 1669-1671 ◽  
Author(s):  
M. H. Hashmi ◽  
G. Morgan-Jones
Keyword(s):  
Time Lapse ◽  
Unique Type ◽  
Nuclear Distribution ◽  
Wallemia Sebi ◽  
Time Lapse Photomicrography

Conidium ontogeny in Wallemia sebi (Fr.) v. Arx is analyzed and illustrated by time-lapse photomicrography. The nuclear configurations occurring during conidiogenesis are described and subsequent nuclear distribution reported. The conidia are considered to be meristem arthrospores of a unique type.

scholarly journals Cell-to-cell heterogeneity in Escherichia coli stress response originates from pulsatile expression and growth

2020 ◽  
Author(s):  
Nadia M. V. Sampaio ◽  
Caroline M. Blassick ◽  
Jean-Baptiste Lugagne ◽  
Mary J. Dunlop
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Stress Response ◽  
Single Cell ◽  
Phenotypic Variability ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Heterogeneity ◽  
Temporal Expression ◽  
Functional Consequences

AbstractCell-to-cell heterogeneity in gene expression and growth can have critical functional consequences, such as determining whether individual bacteria survive or die following stress. Although phenotypic variability is well documented, the dynamics that underlie it are often unknown. This information is critical because dramatically different outcomes can arise from gradual versus rapid changes in expression and growth. Using single-cell time-lapse microscopy, we measured the temporal expression of a suite of stress response reporters in Escherichia coli, while simultaneously monitoring growth rate. In conditions without stress, we found widespread examples of pulsatile expression. Single-cell growth rates were often anti-correlated with gene expression, with changes in growth preceding changes in expression. These pulsatile dynamics have functional consequences, which we demonstrate by measuring survival after challenging cells with the antibiotic ciprofloxacin. Our results suggest that pulsatile expression and growth dynamics are common in stress response networks and can have direct consequences for survival.

scholarly journals The Evolution of Mass Cell Suicide in Bacterial Warfare

2020 ◽  
Author(s):  
Elisa T. Granato ◽  
Kevin R. Foster
Keyword(s):  
Escherichia Coli ◽  
Natural Selection ◽  
Reproductive Potential ◽  
Time Lapse ◽  
List Type ◽  
E Coli ◽  
Toxin Exposure ◽  
Small Benefit ◽  
Will Self ◽  
Cell Suicide

SUMMARYBehaviours that reliably cause the death of an actor are typically strongly disfavoured by natural selection, and yet many bacteria undergo cell lysis to release anti-competitor toxins [1–4]. This behaviour is most easily explained if only a few cells die to release toxins and help their clonemates, but the number of cells that actually lyse during bacterial warfare is unknown. The challenge is that one cannot distinguish cells that have undergone programmed suicide from those that were simply killed by a competitor’s toxin. We developed a two-colour fluorescence reporter assay in Escherichia coli to overcome this problem. Surprisingly, this revealed conditions where nearly all cells undergo programmed lysis. Adding a DNA-damaging toxin (DNase colicin) to a focal strain causes it to engage in mass cell suicide where around 85% of cells lyse to release their own toxin. Time-lapse 3D confocal microscopy revealed that self-lysis occurs at even higher frequencies (~94%) at the interface between competing colonies. We sought to understand how such high levels of cell suicide could be favoured by natural selection. Exposing E. coli that do not perform lysis to the DNase colicin revealed that mass lysis only occurs when cells are going to die anyway from toxin exposure. From an evolutionary perspective, this renders the behaviour cost-free as these cells have zero reproductive potential. This explains how mass cell suicide can evolve, as any small benefit to surviving clonemates can lead to the strategy being favoured by natural selection. Our findings have strong parallels to the suicidal attacks of social insects [5–8], which are also performed by individuals with low reproductive potential, suggesting convergent evolution in these very different organisms.HIGHLIGHTSA novel assay can detect Escherichia coli undergoing cell suicide to release toxinsWe quantified the frequency of suicidal self-lysis during competitionsUnder some conditions, nearly all cells will self-lyse to release toxinsSelf-lysis makes evolutionary sense as cells will die anyway from competitors’ toxins

Continuous Measurement of Biological Noise in Escherichia Coli Using Time-lapse Microscopy

10.3791/61290 ◽  
2021 ◽  
Author(s):  
Einel A. Chaimovitz ◽  
Evgeniy Reznik ◽  
Mouna Habib ◽  
Netanel Korin ◽  
Ramez Daniel
Keyword(s):  
Escherichia Coli ◽  
Continuous Measurement ◽  
Time Lapse ◽  
Biological Noise ◽  
Time Lapse Microscopy

scholarly journals C-terminal eYFP fusion impairs Escherichia coli MinE function

Open Biology ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 200010
Author(s):  
Navaneethan Palanisamy ◽  
Mehmet Ali Öztürk ◽  
Emir Bora Akmeriç ◽  
Barbara Di Ventura
Keyword(s):  
Escherichia Coli ◽  
In Silico ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Yellow Fluorescent Protein ◽  
Time Lapse ◽  
Enhanced Yellow Fluorescent Protein ◽  
Min Proteins

The Escherichia coli Min system plays an important role in the proper placement of the septum ring at mid-cell during cell division. MinE forms a pole-to-pole spatial oscillator with the membrane-bound ATPase MinD, resulting in MinD concentration being the lowest at mid-cell. MinC, the direct inhibitor of the septum initiator protein FtsZ, forms a complex with MinD at the membrane, mirroring its polar gradients. Therefore, MinC-mediated FtsZ inhibition occurs away from mid-cell. Min oscillations are often studied in living cells by time-lapse microscopy using fluorescently labelled Min proteins. Here, we show that, despite permitting oscillations to occur in a range of protein concentrations, the enhanced yellow fluorescent protein (eYFP) C-terminally fused to MinE impairs its function. Combining in vivo , in vitro and in silico approaches, we demonstrate that eYFP compromises the ability of MinE to displace MinC from MinD, to stimulate MinD ATPase activity and to directly bind to the membrane. Moreover, we reveal that MinE-eYFP is prone to aggregation. In silico analyses predict that other fluorescent proteins are also likely to compromise several functionalities of MinE, suggesting that the results presented here are not specific to eYFP.

scholarly journals Vertical and Horizontal Transmission of ESBL Plasmid from Escherichia coli O104:H4

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1207
Author(s):  
Sandra Daniel ◽  
Kelly Goldlust ◽  
Valentin Quebre ◽  
Minjia Shen ◽  
Christian Lesterlin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Plasmid Stability ◽  
Horizontal Transmission ◽  
Viable Cell ◽  
Time Lapse ◽  
Conjugative Plasmid ◽  
Triple Mutant ◽  
Conjugational Transfer ◽  
Transposon Insertion ◽  
Free Cells

Multidrug resistance (MDR) often results from the acquisition of mobile genetic elements (MGEs) that encode MDR gene(s), such as conjugative plasmids. The spread of MDR plasmids is founded on their ability of horizontal transference, as well as their faithful inheritance in progeny cells. Here, we investigated the genetic factors involved in the prevalence of the IncI conjugative plasmid pESBL, which was isolated from the Escherichia coli O104:H4 outbreak strain in Germany in 2011. Using transposon-insertion sequencing, we identified the pESBL partitioning locus (par). Genetic, biochemical and microscopic approaches allowed pESBL to be characterized as a new member of the Type Ib partitioning system. Inactivation of par caused mis-segregation of pESBL followed by post-segregational killing (PSK), resulting in a great fitness disadvantage but apparent plasmid stability in the population of viable cells. We constructed a variety of pESBL derivatives with different combinations of mutations in par, conjugational transfer (oriT) and pnd toxin-antitoxin (TA) genes. Only the triple mutant exhibited plasmid-free cells in viable cell populations. Time-lapse tracking of plasmid dynamics in microfluidics indicated that inactivation of pnd improved the survival of plasmid-free cells and allowed oriT-dependent re-acquisition of the plasmid. Altogether, the three factors—active partitioning, toxin-antitoxin and conjugational transfer—are all involved in the prevalence of pESBL in the E. coli population.

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