Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Eclipse period without sequestration in Escherichia coli.

Jan Olsson1, Santanu Dasgupta, Otto G Berg

  • 1Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden.

Molecular Microbiology
|June 18, 2002
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The first oral relaxin receptor RXFP1 agonist for heart failure treatment: Translational studies from non-human primates to humans.

Molecular therapy. Advances·2026
Same author

Genome-Wide DNA Methylation Profiling Reveals Ancestry-Associated Epigenetic Reprogramming in Cervical Intraepithelial Neoplasia.

International journal of molecular sciences·2026
Same author

Frequent Loss of CACNA1C Is Associated With Poor Prognosis in Non-Small Cell Lung Cancer.

FASEB journal : official publication of the Federation of American Societies for Experimental Biology·2026
Same author

The Current Roadmap of Lung Cancer Biology, Genomics and Racial Disparity.

International journal of molecular sciences·2025
Same author

Age-Dependent Pleomorphism in <i>Mycobacterium monacense</i> Cultures.

Microorganisms·2025
Same author

A novel long-acting relaxin-2 fusion, AZD3427, improves cardiac performance in non-human primates with cardiac dysfunction.

Cardiovascular research·2025
Same journal

Riboflavin Salvage Supports Glycolysis in Borrelia burgdorferi Through Flavin-Dependent NAD<sup>+</sup> Regeneration.

Molecular microbiology·2026
Same journal

Distinct Spatial Organisation of Rho and RNA Polymerase in Salmonella Cells.

Molecular microbiology·2026
Same journal

A Single-Nucleotide Substitution Generates a de Novo Promoter That Activates a Latent Metabolic Bypass in Escherichia coli.

Molecular microbiology·2026
Same journal

A Phosphorylation-Dependent Partner-Switching-Like Module Regulates a Glycosyltransferase Required for Heterocyst Polysaccharide Layer Formation in Anabaena sp. Strain PCC 7120.

Molecular microbiology·2026
Same journal

Chain-Length Regulation by WzzE Is Necessary for, but Genetically Separable From, Cyclic Enterobacterial Common Antigen Synthesis.

Molecular microbiology·2026
Same journal

To Move or Not to Move: When and How Bacteria Suppress Flagellar Motility.

Molecular microbiology·2026
See all related articles

The eclipse period, a crucial time for bacterial DNA replication initiation, was measured in Escherichia coli. This period, where new replication origins are blocked, lasts 0.60 generation times in wild-type bacteria.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • The origin of chromosome replication (oriC) in bacteria must be regulated to ensure proper cell division.
  • The eclipse period is a critical regulatory phase preventing re-initiation from oriC after replication.

Purpose of the Study:

  • To precisely determine the duration of the eclipse period in Escherichia coli using a classical density shift experiment.
  • To investigate the influence of specific genetic mutations (seqA, dam) on the eclipse period length and oriC initiation synchrony.

Main Methods:

  • Utilized the Meselson-Stahl density shift experiment with heavy and light isotope labeling of bacterial DNA.
  • Separated DNA species (HH, HL, LL) via CsCl density gradient centrifugation.
  • Quantified DNA species using radioactive gene-specific probes to track replication kinetics.

Related Experiment Videos

Main Results:

  • The eclipse period in wild-type Escherichia coli was determined to be 0.60 generation times, consistent across various doubling times and chromosomal locations.
  • Mutations in seqA, dam, and damseqA genes significantly altered the eclipse period to 0.16, 0.40, and 0.32 generation times, respectively.
  • oriC initiation remained repressed for a substantial part of the cell cycle even in mutants with compromised sequestration functions.

Conclusions:

  • The eclipse period is a significant, conserved regulatory mechanism in bacterial DNA replication.
  • Genetic factors like SeqA and Dam play crucial roles in modulating the length of the eclipse period and synchronizing oriC initiations.
  • Further research is needed to fully elucidate the causal relationship between eclipse period length and oriC initiation synchrony.