Related Experiment Video
Updated: Aug 4, 2026
07:03
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Experimental analysis of second cleavage in the mouse
1University of Oxford, Department of Zoology, South Parks Road, Oxford OX1 3PS, UK. richard.gardner@zoology.ox.ac.uk
Human Reproduction (Oxford, England)
|November 29, 2002
Summary
Mouse embryo development involves specific cell division patterns. Second cleavage yields a regular tetrahedral shape, not through blastomere rotation, but via distinct division types influencing blastomere axial levels.
Area of Science:
- Developmental Biology
- Mammalian Embryogenesis
- Cellular Dynamics
Background:
- Mammalian conceptuses exhibit a tetrahedral shape at the 4-cell stage.
- Rabbit conceptuses achieve this shape via blastomere rotation during the second cleavage.
- The study investigates if mouse embryos follow a similar developmental pattern.
Purpose of the Study:
- To determine if blastomere rotation occurs during the second cleavage in mouse embryos.
- To understand the mechanism behind the regular tetrahedral shape of 4-cell mouse conceptuses.
Main Methods:
- Analyzing microsphere distribution in 4-cell conceptuses after application to 2-cell blastomeres.
- Investigating conceptus formation after preventing blastomere rotation using gelation.
Main Results:
- No evidence of blastomere rotation during the second cleavage in mouse embryos was found.
- Findings suggest the tetrahedral shape results from meridional and equatorial divisions.
- Microsphere distribution indicated no significant rotation occurred.
Conclusions:
- Second cleavage in mice produces 4-cell conceptuses with three distinct blastomere types.
- Meridional division products contain all zygote axial levels.
- Equatorial division products contain only the animal or vegetal half of the zygote.
