Related Experiment Video
Updated: Apr 17, 2026
06:53
Vitrification of In Vitro Matured Oocytes Collected from Adult and Prepubertal Ovaries in Sheep
Published on: July 10, 2021
5.9K
Oocyte vitrification modifies nucleolar remodeling and zygote kinetics-a sibling study
S Chamayou1, S Romano, C Alecci
1Unità Di Medicina della Riproduzione - Istituto HERA, via Barriera del Bosco n. 51/53, 95030, Sant'Agata Li Battiati, Catania, Italy, s.chamayou@yahoo.fr.
Journal of Assisted Reproduction and Genetics
|February 22, 2015
Summary
Oocyte vitrification impacts early embryo development timing but not overall cleavage stage kinetics. Predictive embryo models for fresh oocytes need revision for vitrified oocytes to ensure accurate fertility preservation assessments.
Area of Science:
- Reproductive Science
- Embryology
- In Vitro Fertilization
Background:
- Oocyte vitrification is a key method for female fertility preservation.
- Morphokinetic parameters are used to predict embryo competence from fresh oocytes.
Purpose of the Study:
- To investigate the impact of oocyte vitrification on zygote and early embryo development kinetics.
- To compare embryo-kinetics between fresh and vitrified/warmed sibling oocytes.
Main Methods:
- A 44-hour time-lapse analysis was conducted from intracytoplasmic sperm injection (ICSI).
- Embryo-kinetics of 179 fertilized fresh oocytes were compared with 168 fertilized sibling vitrified/warmed oocytes.
Main Results:
- Oocyte vitrification accelerated pronuclear disappearance and one-cell stage timing.
- Nucleoli activity was modified at the zygote stage (increased number, decreased diameter).
- Cleavage stage embryo kinetics were similar between fresh and vitrified/warmed oocytes.
Conclusions:
- Oocyte vitrification alters zygote stage pronuclei stability and nucleoli functionality.
- Predictive morphokinetic parameters established for fresh oocytes require revision for embryos from vitrified/warmed oocytes.
Related Concept Videos
01:38Fertilization
94.2K
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...
94.2K
01:57Meiosis II
211.2K
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...
211.2K
01:33Cleavage and Blastulation
51.6K
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.
51.6K
01:22Oogenesis
5.3K
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...
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is...
5.3K
02:07Oogenesis
71.7K
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...
71.7K
01:10Zygotic Development And Stem Cell Formation
7.6K
The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they...
7.6K