The authors discussed the basic strategies for uniting the membranes and cytoplasms …

• Summary
• Introduction
• Attachment and fusion proteins in virus-cell and cell-cell fusion
• The process of fertilization
• Sperm-oocyte attachment and fusion
• The egg
• The sperm
• Perspectives
• References

Biology Articles » Reproductive Biology » Sperm-egg fusion: events at the plasma membrane

Summary

- Sperm-egg fusion: events at the plasma membrane

Commentary

Sperm-egg fusion: events at the plasma membrane

Kathryn K. Stein^1,*, Paul Primakoff² and Diana Myles^1,

¹ Section of Molecular and Cellular Biology, School of Medicine, University of California Davis, Davis, CA 95616, USA
² Department of Cell Biology and Human Anatomy, School of Medicine, University of California Davis, Davis, CA 95616, USA

Author for correspondence (e-mail: dgmyles@ucdavis.edu )

Sperm-egg fusion is a cell-cell membrane fusion event essential for the propagation of sexually reproducing organisms. In gamete fusion, as in other fusion events, such as virus-cell and intracellular vesicle fusion, membrane fusion is a two-step process. Attachment of two membranes through cell-surface molecules is followed by the physical merger of the plasma membrane lipids. Recent progress has demonstrated an essential role for an oocyte tetraspanin, CD9, in mouse sperm-egg fusion, and a specific molecular site crucial for CD9 function has been identified. Absence of glycosylphosphatidylinositol-anchored proteins on the oocyte surface also results in loss of oocyte fusion competence in this gamete. These discoveries provide a strong starting point for the identification of additional proteins that have roles in sperm-egg fusion.

Key words: Membrane fusion, Fertilization, Cell-cell fusion, Sperm, Egg

Source: Journal of Cell Science 117, 6269-6274 (2004).