Related Experiment Video

Updated: Jul 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

Temporal progression of recombination in human males

M Oliver-Bonet1, P J Turek, F Sun

  • 1Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada T2N 4N1.

Molecular Human Reproduction
|August 27, 2005
PubMed

Insights

This study maps key human meiotic recombination proteins, revealing MSH4

Area of Science:

  • Cell Biology
  • Genetics
  • Molecular Biology

Background:

  • Immunocytology has identified limited meiotic proteins in humans.
  • The colocalization of proteins during human meiosis is understudied.
  • Understanding protein interactions is crucial for deciphering recombination mechanics.

Purpose of the Study:

  • To investigate the relative timing and localization of five key meiotic recombination proteins in humans.
  • To explore the potential cooperative roles of RAD51, replication protein A (RPA), MSH4, MLH1, and MLH3 during homologous recombination.
  • To elucidate the function of MSH4 in synapsis initiation and maintenance.

Main Methods:

  • Immunocytology was used to detect and localize meiotic proteins.
  • The study focused on five proteins: RAD51, RPA, MSH4, MLH1, and MLH3.
  • Relative timing and colocalization of protein foci were analyzed during human meiosis.

Main Results:

  • MSH4 foci appear with synapsis initiation at zygotene, following RAD51 foci.
  • RPA was found within MSH4 foci, suggesting cooperative action.
  • RPA and MSH4 foci peaked at the end of zygotene; RPA diminished by pachytene, while MSH4 stabilized and localized with MLH1/MLH3.

Conclusions:

  • MSH4 plays a role in the initiation and/or maintenance of synapsis.
  • The findings provide insights into the temporal and spatial coordination of recombination proteins during human meiosis.
  • Cooperative interactions between RPA and MSH4 are suggested during recombination.

More Related Videos

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes08:46

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes

Published on: March 3, 2020

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging06:44

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging

Published on: April 28, 2021

Related Concept Videos

Crossing Over01:34

Crossing Over

Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Gene Conversion02:08

Gene Conversion

Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
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...
Crossing Over01:30

Crossing Over

Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated...