Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Fertilization

Fertilization

During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...

Cleavage and Blastulation

Cleavage and Blastulation

After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller.

Oogenesis

Oogenesis

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...

Oogenesis

Oogenesis

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 known...

Meiosis II

Meiosis II

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 containing...

What is Meiosis?

What is Meiosis?

Meiosis is the process by which diploid cells divide to produce haploid daughter cells. In humans, each diploid cell contains 46 chromosomes, half from the mother and half from the father. Following meiosis, the resulting haploid eggs or sperm only contain 23 chromosomes; however, each of these chromosomes contains a unique combination of parental information that results from the meiotic process of crossing over.

You might also read

Related Articles

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

Sort by

Same author

Female genetic variation controlling timing of mating plug ejection in <i>Drosophila melanogaster</i>.

bioRxiv : the preprint server for biology·2026

Same author

Correlated gene copy number changes in a seminal fluid protein network in <i>Drosophila</i>.

Proceedings of the National Academy of Sciences of the United States of America·2026

Same author

Transcriptional response of spermathecal secretory cells to mating and receipt of seminal fluid proteins in <i>Aedes aegypti</i>.

iScience·2026

Same author

Characterization of <i>spe-40/Fam187</i> identifies a deeply conserved sperm protein at the <i>C. elegans</i> fertilization synapse.

bioRxiv : the preprint server for biology·2026

Same author

Egg activation.

Current biology : CB·2026

Same author

Pickpocket315 affects male mating behavior in the yellow fever mosquito Aedes aegypti.

G3 (Bethesda, Md.)·2025

Search research articles

Related Experiment Video

Updated: May 15, 2026

Imaging Calcium in Drosophila at Egg Activation

Imaging Calcium in Drosophila at Egg Activation

Published on: August 6, 2016

Molecular changes during egg activation.

Amber R Krauchunas¹, Mariana F Wolfner

¹Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA.

Current Topics in Developmental Biology

|January 5, 2013

Summary

This summary is machine-generated.

Egg activation transforms a mature oocyte into a totipotent cell, involving calcium signals and crucial macromolecular changes. This process ensures proper development by altering the egg

More Related Videos

A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis

A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis

Published on: December 19, 2015

Related Experiment Videos

Last Updated: May 15, 2026

Imaging Calcium in Drosophila at Egg Activation

Imaging Calcium in Drosophila at Egg Activation

Published on: August 6, 2016

A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis

A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis

Published on: December 19, 2015

Area of Science:

Reproductive Biology
Cellular Biology
Developmental Biology

Background:

Egg activation is a critical transition for oocyte development.
It is typically initiated by a calcium signal, often following fertilization.
This process prepares the egg for embryonic development.

Purpose of the Study:

To review the roles of calcium and zinc in egg activation.
To highlight the importance of macromolecular changes during this transition.
To provide a comprehensive overview of the molecular events in egg activation.

Main Methods:

Literature review of studies on egg activation.
Analysis of molecular mechanisms involving calcium, zinc, and macromolecules.
Synthesis of information on changes in ion concentrations, proteome, and mRNA.

Main Results:

Calcium and zinc play key roles in triggering and regulating egg activation.
Significant changes occur in protein translation, degradation, and post-translational modifications.
Maternal mRNAs undergo degradation and polyadenylation, supporting early development.

Conclusions:

Egg activation involves a complex interplay of ionic and macromolecular events.
These coordinated changes convert a differentiated oocyte into a totipotent embryonic cell.
Understanding these processes is vital for reproductive biology and developmental science.