Related Experiment Video

Updated: Jun 29, 2026

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization
17:14

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization

Published on: December 10, 2012

Identification of two Xenopus laevis genes, xMCM2 and xCDC46, with sequence homology to MCM genes involved in DNA

S Miyake1, I Saito, H Kobayashi

  • 1Department of Biochemistry, Toho University School of Medicine, Tokyo, Japan.

Gene
|October 10, 1996
PubMed

Insights

Researchers identified two new MCM genes, xMCM2 and xCDC46, in Xenopus laevis, crucial for DNA replication initiation. These genes physically interact, suggesting a role in regulating DNA replication.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Genetics

Background:

  • The MCM gene family is essential for DNA replication initiation across eukaryotes.
  • Previous studies identified key MCM genes in yeast and humans, highlighting their conserved function.
  • Homologues of these replication factors are expected in other species, including Xenopus laevis.

Purpose of the Study:

  • To identify and characterize novel MCM gene homologues in Xenopus laevis.
  • To investigate the relationship and potential interaction between these Xenopus MCM genes.

Main Methods:

  • Polymerase chain reaction (PCR) was used to isolate Xenopus MCM2 (xMCM2) and MCM46 (xCDC46) homologues from a cDNA library.
  • Amino acid sequence similarity was analyzed against known MCM proteins.
  • Western blot analysis and immunoprecipitation assays were performed using specific polyclonal antibodies.

Main Results:

  • Two Xenopus MCM gene homologues, xMCM2 and xCDC46, were successfully isolated.
  • Sequence analysis revealed xMCM2 is most similar to human BM28, and xCDC46 to S. pombe Nda4.
  • Western blots identified xMCM2 as a 120-kDa and xCDC46 as a 95-kDa protein.
  • Co-immunoprecipitation demonstrated that xMCM2 and xCDC46 physically interact.

Conclusions:

  • xMCM2 and xCDC46 are Xenopus homologues of essential DNA replication initiation factors.
  • These proteins form a complex, suggesting a conserved functional interaction in DNA replication regulation.

More Related Videos

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts10:55

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts

Published on: November 5, 2012

Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG10:11

Hybrid Ensemble and Single-molecule Assay to Image the Motion of Fully Reconstituted CMG

Published on: July 26, 2024

Related Concept Videos

X-Inactivation01:58

X-Inactivation

The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.
Inheritance of Chromatin Structures03:17

Inheritance of Chromatin Structures

Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
The Replisome03:01

The Replisome

DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Exon Recombination02:32

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. 
Exon shuffling follows “splice frame rules.” Each exon has three reading...
S-Cdk Initiates DNA Replication02:38

S-Cdk Initiates DNA Replication

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 replication.
S-Cdk Initiates DNA Replication02:38

S-Cdk Initiates DNA Replication

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 replication.