Related Experiment Video
Updated: Jul 7, 2026
Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats
Published on: October 13, 2018
Severely reduced female fertility in CD9-deficient mice
F Le Naour1, E Rubinstein, C Jasmin
1Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 268, Hôpital Paul-Brousse, 94800 Villejuif, France.
Abstract:
CD9 is a widely expressed cell surface molecule that belongs to the tetraspanin superfamily of proteins. The tetraspanins CD9, KAI-1/CD82, and CD63 are involved in metastasis suppression, an effect that may be related to their association with beta1 integrins. Knockout mice lacking CD9 were created to evaluate the physiological importance of CD9. CD9-/- females displayed a severe reduction of fertility. Oocytes were ovulated but were not successfully fertilized because sperm did not fuse with the oocytes from CD9-/- females. Thus, CD9 appears to be essential for sperm-egg fusion, a process involving the CD9-associated integrin alpha6beta1.
Insights
The cell surface molecule CD9 (cluster of differentiation 9) is crucial for fertility. CD9 knockout mice show impaired sperm-egg fusion, highlighting CD9
Area of Science:
- Reproductive biology
- Cellular and molecular biology
- Immunology
Background:
- CD9 is a tetraspanin protein expressed on cell surfaces.
- Tetraspanins like CD9, CD63, and KAI-1/CD82 are implicated in metastasis suppression, potentially via beta1 integrin interactions.
- The physiological role of CD9 requires further investigation.
Purpose of the Study:
- To investigate the physiological importance of CD9 using knockout mice.
- To determine the role of CD9 in fertility and reproduction.
Main Methods:
- Generation of CD9 knockout (CD9-/-) mice.
- Assessment of fertility in CD9-/- female mice.
- Evaluation of sperm-egg fusion in CD9-/- mice.
Main Results:
- CD9 knockout females exhibited significantly reduced fertility.
- Oocytes were ovulated but fertilization failed due to lack of sperm-egg fusion.
- Sperm fusion with oocytes from CD9-/- mice was unsuccessful.
Conclusions:
- CD9 is essential for successful sperm-egg fusion.
- The CD9-associated integrin alpha6beta1 is involved in this critical reproductive process.
- CD9 plays a vital role in mammalian fertility.
