Related Experiment Video

Updated: Jul 15, 2026

Preparation of Meiotic Chromosome Spreads from Mouse Oocytes for Assessment of Synapsis and Recombination
09:24

Preparation of Meiotic Chromosome Spreads from Mouse Oocytes for Assessment of Synapsis and Recombination

Published on: July 18, 2025

A dominant, recombination-defective allele of Dmc1 causing male-specific sterility

Laura A Bannister1, Roberto J Pezza, Janet R Donaldson

  • 1Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America.

Plos Biology
|April 12, 2007
PubMed

Insights

A dominant mutation in the DMC1 gene causes male sterility by disrupting DNA repair during meiosis. Female mice show some compensation, highlighting sex differences in recombination and potential reproductive issues.

Area of Science:

  • Genetics
  • Molecular Biology
  • Reproductive Biology

Background:

  • DMC1 is crucial for homologous DNA repair and chromosome synapsis during meiosis.
  • Defects in DMC1 lead to sterility in mice and yeast due to impaired meiotic recombination.

Purpose of the Study:

  • To investigate the functional consequences of a dominant Dmc1 allele, Dmc1(Mei11), on male and female meiosis.
  • To understand the role of DMC1 in meiotic recombination and its sex-specific effects.

Main Methods:

  • Identification and characterization of the Dmc1(Mei11) allele.
  • Analysis of meiotic progression, chromosome synapsis, and recombination in heterozygous Dmc1(Mei11) mice.
  • Assessment of reproductive capacity and oocyte health in affected females.

Main Results:

  • The Dmc1(Mei11) mutation impairs DNA strand invasion activity, leading to meiotic arrest in male heterozygotes.
  • Male heterozygotes exhibit incomplete synapsis and lack of crossing over.
  • Female heterozygotes show a decreased oocyte pool and increased meiosis I abnormalities, but some can compensate for DMC1 deficiency.
  • A significant sex difference in recombination compensation was observed.

Conclusions:

  • Dominant alleles of meiosis genes can emerge and spread, causing infertility.
  • The Dmc1(Mei11) mutation reveals sex-specific differences in meiotic recombination and compensation mechanisms.
  • Meiotic prophase I defects can lead to reproductive consequences and infertility.

More Related Videos

Removal of an Internal Translational Start Site from mRNA While Retaining Expression of the Full-Length Protein05:48

Removal of an Internal Translational Start Site from mRNA While Retaining Expression of the Full-Length Protein

Published on: March 16, 2022

Inducible and Reversible Dominant-negative (DN) Protein Inhibition08:35

Inducible and Reversible Dominant-negative (DN) Protein Inhibition

Published on: January 7, 2019

Related Concept Videos

The Ratio of X Chromosome to Autosomes02:45

The Ratio of X Chromosome to Autosomes

In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.  
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
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...
Dosage Compensation02:50

Dosage Compensation

In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with  distinct numbers of X chromosomes will have...
Sex-linked Disorders01:43

Sex-linked Disorders

Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
The Y Chromosome Determines Maleness02:19

The Y Chromosome Determines Maleness

The Y chromosome is a sex chromosome found in several vertebrates and mammals, including humans. In addition to 22 pairs of autosomes, the human males have one X chromosome and one Y chromosome. In these organisms, the presence or absence of the Y chromosome determines the development of male traits.
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
In-vitro Mutagenesis01:16

In-vitro Mutagenesis

To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.