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Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Normal mice develop from oocytes injected with spermatozoa with grossly misshapen heads
V R Burruel1, R Yanagimachi, W K Whitten
1Department of Anatomy and Reproductive Biology, University of Hawaii School of Medicine, Honolulu 96822, USA.
Biology of Reproduction
|September 1, 1996
Summary
Structurally abnormal mouse spermatozoa with misshapen heads can fertilize oocytes. Some resulting embryos develop into apparently normal, fertile adult mice, indicating these sperm carry necessary genetic material for development.
Area of Science:
- Reproductive biology
- Spermatozoa morphology
- Embryonic development
Background:
- Structurally abnormal spermatozoa can penetrate oocytes in mice.
- The developmental capacity of oocytes fertilized by morphologically abnormal sperm is largely unknown.
Purpose of the Study:
- To investigate the developmental potential of mouse oocytes fertilized by spermatozoa with grossly misshapen heads.
- To determine if abnormal sperm can support normal embryonic development and fertility.
Main Methods:
- Intracytoplasmic sperm injection (ICSI) of morphologically abnormal BALB/c mouse spermatozoa into B6D2F1 hybrid oocytes.
- In vitro culture of fertilized oocytes to the blastocyst stage.
- Transfer of blastocysts to foster mothers for in vivo development.
Main Results:
- Eighty to ninety percent of oocytes activated and developed into blastocysts in vitro after ICSI with abnormal sperm.
- Some resulting offspring developed into apparently normal, fertile adult mice.
- A proportion of morphologically abnormal spermatozoa possess the necessary genetic and organelle content for normal development.
Conclusions:
- Morphological abnormalities in spermatozoa, such as misshapen heads, do not necessarily preclude successful fertilization and embryonic development.
- A subset of structurally abnormal spermatozoa can support complete development to fertile maturity.
- These findings challenge traditional criteria for sperm morphology assessment in reproductive potential.
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