Related Experiment Video
Updated: Jun 17, 2026
06:18
Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
Two types of meiotic crossovers coexist in maize
Matthieu Falque1, Lorinda K Anderson, Stephen M Stack
1Institut National de la Recherche Agronomique, Unité Mixte de Recherche 0320/Unité Mixte de Recherche 8120 Génétique Végétale, F-91190 Gif-sur-Yvette, France. falque@moulon.inra.fr
The Plant Cell
|December 31, 2009
Summary
Maize (Zea mays) recombination nodules suggest two crossover types coexist. Approximately 15% of crossovers arise from a non-interfering pathway, influenced by chromosome length.
Area of Science:
- Genetics
- Molecular Biology
- Computational Biology
Background:
- Recombination nodules mark crossover sites during meiosis.
- Understanding crossover interference is crucial for genetic mapping and understanding genome stability.
- Previous studies suggested multiple crossover pathways in other organisms.
Purpose of the Study:
- To investigate the distribution of late recombination nodules in maize (Zea mays).
- To test the hypothesis of a single crossover formation pathway versus multiple pathways.
- To develop new tools for analyzing complex crossover interference models.
Main Methods:
- Analysis of high-quality recombination nodule data in maize.
- Application of two interference models: the statistical gamma model and the mechanical beam film model.
- Statistical analysis to exclude the hypothesis of a single crossover pathway.
Main Results:
- Evidence supports the coexistence of two distinct crossover pathways in maize.
- The proportion of non-interfering crossovers ranges from 6% to 23% per chromosome, averaging 15% across the cell.
- The number of non-interfering crossovers correlates significantly with synaptonemal complex length.
Conclusions:
- Maize exhibits at least two distinct crossover formation mechanisms.
- Developed novel inference tools for complex crossover interference models, overcoming limitations of parameter estimation.
- These advancements enable more realistic modeling of crossover formation mechanisms in the future.
Related Concept Videos
01:34Crossing 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...
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...
01:30Crossing 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...
01:34Crossing 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...
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...
02:08Gene 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...
01:49Meiosis I
Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by a...
03:09Meiosis I
Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of meiosis, where the genetic recombination of homologous chromosomes and the reduction of the ploidy level by half occurs.
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...