Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Meiosis II02:02

Meiosis II

51.1K
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
51.1K
Meiosis II01:57

Meiosis II

209.7K
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each...
209.7K
Oogenesis01:22

Oogenesis

4.5K
Oogenesis,  the process of developing egg cells (female gametes), occurs within the ovaries and is fundamental to female fertility. This sequence begins during fetal development when diploid oogonia in the developing ovaries undergo mitotic divisions to produce primary oocytes. By birth, these primary oocytes enter prophase I of meiosis but become arrested in this stage, remaining suspended until puberty.
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is...
4.5K
Oogenesis02:07

Oogenesis

70.8K
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...
70.8K
Meiosis I03:09

Meiosis I

46.0K
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...
46.0K
Meiosis I01:49

Meiosis I

220.9K
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...
220.9K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The mid-pachytene transition between early and late double-strand breaks in C. elegans meiosis is conserved throughout early adulthood and coincides with a peak in recombination intermediates.

G3 (Bethesda, Md.)·2026
Same author

Analysis of rad-51 separation of function allele suggests divergence of the synthesis-dependent strand annealing and double Holliday junction pathways prior to RAD-51 filament disassembly.

Genetics·2025
Same author

Overlapping and separable activities of BRA-2 and HIM-17 promote occurrence and regulation of pairing and synapsis during Caenorhabditis elegans meiosis.

Nature communications·2025
Same author

Temporal Analysis of DSB Repair Outcome in Caenorhabditis elegans Meiosis.

Methods in molecular biology (Clifton, N.J.)·2024
Same author

High resolution maps of chromatin reorganization through mouse meiosis reveal novel features of the 3D meiotic structure.

bioRxiv : the preprint server for biology·2024
Same author

Continuous double-strand break induction and their differential processing sustain chiasma formation during Caenorhabditis elegans meiosis.

Cell reports·2022

Related Experiment Video

Updated: Mar 7, 2026

Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II
10:39

Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II

Published on: February 26, 2018

16.6K

Prophase I: Preparing Chromosomes for Segregation in the Developing Oocyte.

Rachel Reichman1, Benjamin Alleva1, Sarit Smolikove2

  • 1Department of Biology, University of Iowa, Iowa City, IA, 52242, USA.

Results and Problems in Cell Differentiation
|March 2, 2017
PubMed
Summary

Meiosis is crucial for creating eggs, involving chromosome pairing and crossover formation during prophase I. Errors in these processes can lead to chromosome missegregation and aneuploidy, particularly with advanced maternal age.

More Related Videos

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

1.2K
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
07:03

Mouse Oocyte Microinjection, Maturation and Ploidy Assessment

Published on: July 23, 2011

30.9K

Related Experiment Videos

Last Updated: Mar 7, 2026

Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II
10:39

Chromatin Spread Preparations for the Analysis of Mouse Oocyte Progression from Prophase to Metaphase II

Published on: February 26, 2018

16.6K
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

1.2K
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
07:03

Mouse Oocyte Microinjection, Maturation and Ploidy Assessment

Published on: July 23, 2011

30.9K

Area of Science:

  • Cell Biology
  • Genetics
  • Reproductive Biology

Background:

  • Oocyte formation relies on meiosis, a specialized cell division process.
  • Meiotic prophase I involves complex chromosomal events essential for accurate gamete formation.
  • Proper chromosome segregation in meiosis is critical for preventing aneuploidy.

Purpose of the Study:

  • To elucidate the intricate events of meiotic prophase I, focusing on recombination and synapsis.
  • To understand the molecular mechanisms underlying crossover formation and its link to chromosome cohesion.
  • To explore the connection between errors in meiotic prophase I and aneuploidy, especially in relation to aging.

Main Methods:

  • Investigated the role of programmed double-strand breaks in initiating recombination.
  • Examined the function of the synaptonemal complex in facilitating accurate crossover repair.
  • Analyzed signaling pathways connecting recombination and synapsis during meiotic prophase I.

Main Results:

  • Crossover formation, dependent on homologous recombination and sister chromatid cohesion, establishes physical links between homologous chromosomes.
  • The synaptonemal complex provides a scaffold for accurate repair of double-strand breaks, leading to crossovers.
  • Disruptions in meiotic prophase I events, including recombination and synapsis, result in chromosome missegregation.

Conclusions:

  • Successful completion of meiotic prophase I events is a prerequisite for proper chromosome segregation.
  • Meiotic errors, potentially increasing with age, contribute to aneuploidy in oocytes from older females.
  • Understanding these fundamental meiotic processes is vital for addressing age-related reproductive challenges.