scholarly journals Spatial Self-Organization Resolves Conflicts Between Individuality and Collective Migration

2018 ◽  
Author(s):  
X. Fu ◽  
S. Kato ◽  
J. Long ◽  
H.H. Mattingly ◽  
C. He ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Collective Behavior ◽  
Self Organization ◽  
Collective Migration ◽  
Moving Band ◽  
Minimum Performance

AbstractCollective behavior can spontaneously emerge when individuals follow common rules of interaction. However, the behavior of each individual will differ due to existing genetic and non-genetic variation within the population. It remains unclear how this individuality is managed to achieve collective behavior. We quantified individuality in bands of clonalEscherichia colicells that migrate collectively along a channel by following a self-generated gradient of attractant. We discovered that despite substantial differences in individual chemotactic abilities, the cells are able to migrate as a coherent group by spontaneously sorting themselves within the moving band. This sorting mechanism ensures that differences between individual chemotactic abilities are compensated by differences in the local steepness of the traveling gradient each individual must navigate, and determines the minimum performance required to travel with the band. By resolving conflicts between individuality and collective migration, this mechanism enables populations to maintain advantageous diversity while on the move.

scholarly journals Long-Term Experimental Evolution in Escherichia coli. VI. Environmental Constraints on Adaptation and Divergence

Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Michael Travisano
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Experimental Evolution ◽  
Population Genetic ◽  
Environmental Constraints ◽  
Asymmetric Pattern ◽  
Nutrient Environment ◽  
Mean Fitness ◽  
Population Genetic Variation

The effect of environment on adaptation and divergence was examined in two sets of populations of Escherichia coli selected for 1000 generations in either maltose- or glucose-limited media. Twelve replicate populations selected in maltose-limited medium improved in fitness in the selected environment, by an average of 22.5%. Statistically significant among-population genetic variation for fitness was observed during the course of the propagation, but this variation was small relative to the fitness improvement. Mean fitness in a novel nutrient environment, glucose-limited medium, improved to the same extent as in the selected environment, with no statistically significant among-population genetic variation. In contrast, 12 replicate populations previously selected for 1000 generations in glucose-limited medium showed no improvement, as a group, in fitness in maltose-limited medium and substantial genetic variation. This asymmetric pattern of correlated responses suggests that small changes in the environment can have profound effects on adaptation and divergence.

scholarly journals Distinct roles of tumor associated mutations in collective cell migration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachel M. Lee ◽  
Michele I. Vitolo ◽  
Wolfgang Losert ◽  
Stuart S. Martin
Keyword(s):  
Collective Behavior ◽  
Metastatic Potential ◽  
Breast Epithelial Cell ◽  
Collective Cell Migration ◽  
Label Free ◽  
Collective Migration ◽  
Contrast Imaging ◽  
Pten Deletion

AbstractRecent evidence suggests that groups of cells are more likely to form clinically dangerous metastatic tumors, emphasizing the importance of understanding mechanisms underlying collective behavior. The emergent collective behavior of migrating cell sheets in vitro has been shown to be disrupted in tumorigenic cells but the connection between this behavior and in vivo tumorigenicity remains unclear. We use particle image velocimetry to measure a multidimensional migration phenotype for genetically defined human breast epithelial cell lines that range in their in vivo behavior from non-tumorigenic to aggressively metastatic. By using cells with controlled mutations, we show that PTEN deletion enhances collective migration, while Ras activation suppresses it, even when combined with PTEN deletion. These opposing effects on collective migration of two mutations that are frequently found in patient tumors could be exploited in the development of novel treatments for metastatic disease. Our methods are based on label-free phase contrast imaging, and thus could easily be applied to patient tumor cells. The short time scales of our approach do not require potentially selective growth, and thus in combination with label-free imaging would allow multidimensional collective migration phenotypes to be utilized in clinical assessments of metastatic potential.

scholarly journals Acquisition of virulence-associated factors by the enteric pathogens Escherichia coli and Salmonella enterica

2001 ◽  
Vol 356 (1411) ◽  
pp. 1027-1034 ◽  
Author(s):  
John Wain ◽  
Deborah House ◽  
Derek Pickard ◽  
Gordon Dougan ◽  
Gad Frankel
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Salmonella Enterica ◽  
Associated Factors ◽  
Enteric Pathogens ◽  
Genomic Studies ◽  
Shed Light

In this review we summarize recent genomic studies that shed light on the mechanism through which pathogenic Escherichia coli and Salmonella enterica have evolved. We show how acquisition of DNA at specific sites on the chromosome has contributed to increased genetic variation and virulence of these two genera of the Enterobacteriaceae.

scholarly journals Self-organization Assay for Min Proteins of Escherichia coli in Micro-droplets Covered with Lipids

BIO-PROTOCOL ◽  
2020 ◽  
Vol 10 (6) ◽  
Author(s):  
Shunshi Kohyama ◽  
Kei Fujiwara ◽  
Natsuhiko Yoshinaga
Keyword(s):  
Escherichia Coli ◽  
Self Organization ◽  
Min Proteins

scholarly journals Emergence of self-organized multivortex states in flocks of active rollers

2020 ◽  
Vol 117 (18) ◽  
pp. 9706-9711 ◽  
Author(s):  
Koohee Han ◽  
Gašper Kokot ◽  
Oleh Tovkach ◽  
Andreas Glatz ◽  
Igor S. Aranson ◽  
...  
Keyword(s):  
Computational Modeling ◽  
Collective Behavior ◽  
Rotational Motion ◽  
Collective Motion ◽  
Self Organization ◽  
Design Strategies ◽  
Vortex Phase ◽  
Active Elements ◽  
Self Organized ◽  
Dynamic Materials

Active matter, both synthetic and biological, demonstrates complex spatiotemporal self-organization and the emergence of collective behavior. A coherent rotational motion, the vortex phase, is of great interest because of its ability to orchestrate well-organized motion of self-propelled particles over large distances. However, its generation without geometrical confinement has been a challenge. Here, we show by experiments and computational modeling that concentrated magnetic rollers self-organize into multivortex states in an unconfined environment. We find that the neighboring vortices more likely occur with the opposite sense of rotation. Our studies provide insights into the mechanism for the emergence of coherent collective motion on the macroscale from the coupling between microscale rotation and translation of individual active elements. These results may stimulate design strategies for self-assembled dynamic materials and microrobotics.

scholarly journals The Min-protein oscillations in Escherichia coli : an example of self-organized cellular protein waves

2018 ◽  
Vol 373 (1747) ◽  
pp. 20170111 ◽  
Author(s):  
Lukas Wettmann ◽  
Karsten Kruse
Keyword(s):  
Escherichia Coli ◽  
Cell Biology ◽  
Experimental Studies ◽  
Cellular Protein ◽  
Self Organization ◽  
Division Site ◽  
Min Proteins ◽  
Spatio Temporal

In the rod-shaped bacterium Escherichia coli , selection of the cell centre as the division site involves pole-to-pole oscillations of the proteins MinC, MinD and MinE. This spatio-temporal pattern emerges from interactions among the Min proteins and with the cytoplasmic membrane. Combining experimental studies in vivo and in vitro together with theoretical analysis has led to a fairly good understanding of Min-protein self-organization. In different geometries, the system can, in addition to standing waves, also produce travelling planar and spiral waves as well as coexisting stable stationary distributions. Today it stands as one of the best-studied examples of cellular self-organization of proteins. This article is part of the theme issue ‘Self-organization in cell biology’.

Genetic variation in the conjugative plasmidome of a hospital effluent multidrug resistant Escherichia coli strain

Chemosphere ◽  
2019 ◽  
Vol 220 ◽  
pp. 748-759 ◽  
Author(s):  
Catarina Ferreira ◽  
Diana Bogas ◽  
Santosh K. Bikarolla ◽  
Ana Rita Varela ◽  
Karolin Frykholm ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Hospital Effluent
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