Related Experiment Video
Updated: Jan 29, 2026
10:59
Visualizing the Conformational Dynamics of Membrane Receptors Using Single-Molecule FRET
Published on: August 17, 2022
3.8K
High-Copy-Number Plasmid Segregation-Single-Molecule Dynamics in Single Cells.
1Department of Physics, National Taiwan Normal University, Taipei, Taiwan.
Biophysical Journal
|February 19, 2019
Summary
Researchers tracked bacterial high-copy-number (hcn) plasmids to reveal forces like entropic and elastic recoiling, improving models for DNA segregation and intracellular polymer dynamics.
Area of Science:
- Microbiology
- Biophysics
- Molecular Biology
Background:
- Bacterial high-copy-number (hcn) plasmids serve as models for studying DNA segregation.
- Understanding intracellular DNA dynamics is crucial for cell biology.
Purpose of the Study:
- To investigate the physical mechanisms governing DNA segment segregation within bacterial cells.
- To develop predictive models for segregation heterogeneity using observed forces.
Main Methods:
- Utilized two-color fluorescent repressor-operator systems to track single hcn plasmid molecules.
- Employed a synthetic repressible replication origin for precise control.
- Analyzed plasmid diffusion dynamics and motile behaviors in individual cells.
Main Results:
- Observed between-plasmid temporal associations (clustering) and recoiling forces (entropic, elastic).
- Quantified entropic exclusion strength and dynamic DNA segment associations.
- Demonstrated the predictive power of identified forces on segregation heterogeneity.
Conclusions:
- Novel approach elucidates polymer dynamics of DNA in confined cellular environments.
- Findings contribute to understanding bacterial chromosome segregation.
- Identified forces offer insights into intracellular spatial organization and DNA movement.
Related Concept Videos
01:49Law of Segregation
77.9K
When crossing pea plants, Mendel noticed that one of the parental traits would sometimes disappear in the first generation of offspring, called the F1 generation, and could reappear in the next generation (F2). He concluded that one of the traits must be dominant over the other, thereby causing masking of one trait in the F1 generation. When he crossed the F1 plants, he found that 75% of the offspring in the F2 generation had the dominant phenotype, while 25% had the recessive phenotype.
77.9K
02:21Cancers Originate from Somatic Mutations in a Single Cell
14.9K
Cancer arises from mutations in the critical genes that allow healthy cells to escape cell cycle regulation and acquire the ability to proliferate indefinitely. Though originating from a single mutation event in one of the originator cells, cancer progresses when the mutant cell lines continue to gain more and more mutations, and finally, become malignant. For example, chronic myelogenous leukemia (CML) develops initially as a non-lethal increase in white blood cells, which progressively...
14.9K
01:29Load along a Single Axis
643
In structural engineering, the analysis of beams subjected to varying loads is a critical aspect of understanding the behavior and performance of these structural elements. A common scenario involves a beam subjected to a combination of different load distributions.
Consider a beam of length L subjected to a varying load, which is a combination of parabolic and trapezoidal load distribution along the x-axis. In this case, it is essential to determine the resultant loads, their locations, and...
Consider a beam of length L subjected to a varying load, which is a combination of parabolic and trapezoidal load distribution along the x-axis. In this case, it is essential to determine the resultant loads, their locations, and...
643
01:24Single Pipe Systems
450
In pipe flow analysis, problems are typically categorized into three types — Type I, Type II, and Type III — based on the known parameters and the desired outcome. Each type of problem addresses specific engineering requirements using fluid properties, pipe characteristics, and operational conditions.
In a Type I problem, fluid properties (density and viscosity), pipe characteristics (including diameter, length, and surface roughness), and the flow rate or average velocity are...
In a Type I problem, fluid properties (density and viscosity), pipe characteristics (including diameter, length, and surface roughness), and the flow rate or average velocity are...
450
01:16Segregation in Fresh Concrete
576
Segregation in fresh concrete is a phenomenon where the components of the concrete mix separate, leading to uneven distribution and compromised structural integrity. This separation typically occurs when concrete is subjected to excessive horizontal movement within forms, or when it is dropped from considerable heights or forced through narrow, winding paths. As a result, heavier coarse aggregate particles settle at the bottom, while lighter, finer materials such as cement and water rise to the...
576
01:10Angular Momentum: Single Particle
7.8K
Angular momentum is directed perpendicular to the plane of the rotation, and its magnitude depends on the choice of the origin. The perpendicular vector joining the linear momentum vector of an object to the origin is called the “lever arm.” If the lever arm and linear momentum are collinear, then the magnitude of the angular momentum is zero. Therefore, in this case, the object rotates about the origin such that it lies on the rim of the circumference defined by the lever arm...
7.8K