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 Concept Videos

DNA Replication02:40

DNA Replication

59.0K
DNA replication involves the separation of the two strands of the double helix, with each strand serving as a template from which the new complementary strand is copied.  After replication, each double-stranded DNA includes one parental or “old” strand and one “new” strand. This is known as semiconservative replication. The resulting DNA molecules have the same sequence and are divided equally into the two daughter cells.
Replication in Prokaryotes
DNA replication...
59.0K
The DNA Replication Fork01:02

The DNA Replication Fork

40.6K
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork.   Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication...
40.6K
The DNA Replication Fork01:02

The DNA Replication Fork

18.3K
18.3K
Chromosome Replication02:31

Chromosome Replication

10.5K
Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone proteins.  This process begins at numerous origins of replication during the S phase of the cell cycle in each of a cell’s chromosomes simultaneously. Certain nucleotides can act as origins of replication, but these sequences are not well defined - especially in complex, multi-cellular, eukaryotic species. The length of DNA that spans an origin...
10.5K
Genome-wide Association Studies-GWAS01:11

Genome-wide Association Studies-GWAS

15.4K
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
15.4K
S-Cdk Initiates DNA Replication02:38

S-Cdk Initiates DNA Replication

5.5K
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of...
5.5K

You might also read

Related Articles

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

Sort by
Same author

Automated mapping of DNA replication fork progression in human cells with ForkML.

Nature communications·2026
Same author

Actomyosin-dependent assembly of the mechanosensitive machinery from adherens junctions triggers actin polymerization and organization.

Science advances·2026
Same author

Dual DNA replication modes: varying fork speeds and initiation rates within the spatial replication program in Xenopus.

Nucleic acids research·2025
Same author

Rif1 restrains the rate of replication origin firing in Xenopus laevis.

Communications biology·2023
Same author

Talin and kindlin cooperate to control the density of integrin clusters.

Journal of cell science·2023
Same author

A non-transcriptional function of Yap regulates the DNA replication program in <i>Xenopus laevis</i>.

eLife·2022

Related Experiment Video

Updated: Jan 24, 2026

Genome-wide Determination of Mammalian Replication Timing by DNA Content Measurement
08:06

Genome-wide Determination of Mammalian Replication Timing by DNA Content Measurement

Published on: January 19, 2017

8.8K

Genome wide decrease of DNA replication eye density at the midblastula transition of Xenopus laevis.

Marie Platel1, Hemalatha Narassimprakash1, Diletta Ciardo1

  • 1a Department of Genome Biology , Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Sud, University Paris-Saclay , Gif-sur-Yvette , France.

Cell Cycle (Georgetown, Tex.)
|May 28, 2019
PubMed
Summary

Early embryonic DNA replication slows after the midblastula transition (MBT) due to fewer replication origins firing. This slowdown in Xenopus laevis is caused by limiting factors, not dNTP availability.

Keywords:
DNA combingDNA replicationS-phaseXenopus laevismidblastula transition (MBT)replication origins

More Related Videos

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles
06:32

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

Published on: September 4, 2019

6.7K
Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells
14:26

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

Published on: April 4, 2016

25.9K

Related Experiment Videos

Last Updated: Jan 24, 2026

Genome-wide Determination of Mammalian Replication Timing by DNA Content Measurement
08:06

Genome-wide Determination of Mammalian Replication Timing by DNA Content Measurement

Published on: January 19, 2017

8.8K
Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles
06:32

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

Published on: September 4, 2019

6.7K
Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells
14:26

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

Published on: April 4, 2016

25.9K

Area of Science:

  • Developmental Biology
  • Molecular Biology
  • Cell Biology

Background:

  • Early embryonic cell cycles are characterized by rapid divisions and shortened S phases.
  • The DNA:cytoplasm ratio increases until the midblastula transition (MBT), after which transcription resumes and cell cycles lengthen.

Purpose of the Study:

  • To investigate the molecular mechanisms causing the slowdown of DNA replication S phase after the MBT in Xenopus laevis.
  • To determine if dNTP availability or limiting factors regulate replication timing during early development.

Main Methods:

  • Utilized DNA fiber studies in Xenopus laevis embryos.
  • Employed an embryonic in vitro replication system using Xenopus laevis egg extracts.

Main Results:

  • S phase slows down post-MBT due to a genome-wide decrease in replication eye density.
  • Increasing the deoxynucleotide triphosphate (dNTP) pool did not accelerate S phase or increase replication eye density.
  • Replicating the DNA:cytoplasm ratio in egg extracts recapitulated embryonic replication program changes.

Conclusions:

  • dNTPs are not rate-limiting for DNA replication at the Xenopus MBT.
  • Titration of soluble limiting factors likely explains the observed changes in the DNA replication program at the MBT.
  • The DNA:cytoplasm ratio is a key regulator of DNA replication timing during early Xenopus development.