Related Experiment Video
Updated: Oct 25, 2025
17:14
Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization
Published on: December 10, 2012
14.1K
First come, first served: Mammalian recombination is timed to replication
Jason A Halliwell1, Eva R Hoffmann1
1DNRF Center for Chromosome Stability, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Cell
|August 6, 2021
Summary
Researchers mapped DNA replication origins in mammalian tissue, discovering evolutionary links between replication timing and meiotic recombination in males, crucial for fertility.
Area of Science:
- Genetics
- Molecular Biology
- Reproductive Biology
Background:
- Meiotic recombination is vital for creating new chromosome combinations in germ cells and ensuring mammalian fertility.
- Understanding the regulation of DNA replication and its relationship with recombination is key to reproductive health.
Purpose of the Study:
- To develop and apply a novel method for directly mapping DNA replication origins within mammalian tissue.
- To investigate the relationship between replication timing and meiotic recombination patterns in male mammals.
Main Methods:
- A new technique was employed to pinpoint DNA replication origins directly in intact mammalian tissue.
- The spatial and temporal patterns of replication origins were analyzed in relation to meiotic recombination hotspots.
Main Results:
- The study successfully mapped replication origins in mammalian tissue, a first for this type of analysis.
- Significant evolutionary conservation was observed between the timing of DNA replication and the locations of meiotic recombination events in males.
Conclusions:
- The findings establish a novel method for studying DNA replication in vivo.
- This research reveals an unexpected evolutionary link between DNA replication timing and meiotic recombination, impacting our understanding of germ cell development and fertility.
Related Concept Videos
02:31Homologous Recombination
56.6K
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...
56.6K
02:31Homologous Recombination
5.2K
5.2K
02:53Conservative Site-specific Recombination and Phase Variation
6.3K
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...
The recognition sites for Cre recombinase called LoxP...
6.3K
01:30Crossing Over
5.1K
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,...
5.1K
01:34Crossing Over
150.8K
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...
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...
150.8K
02:31Chromosome Replication
9.6K
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...
9.6K