Mammalian membrane block to polyspermy: New insights into how mammalian eggs prevent fertilisation by multiple sperm

Allison J. Gardner, Janice Perry Evans

Research output: Contribution to journalArticle


To inhibit fertilisation by more than one sperm (a condition known as polyspermy), eggs have developed preventative mechanisms known as blocks to polyspermy. The block at the level of the egg extracellular coat (the zona pellucida in mammals, the vitelline envelope in non-mammals) has been well characterised in many different animal species and the block at the level of the egg plasma membrane is understood in some non-mammalian species. However, virtually nothing is known about the membrane block to polyspermy in mammalian eggs, despite data dating back 50-90 years that provide evidence for its existence. In the present review, we will discuss the background on blocks to polyspermy used by animal eggs and then focus on the membrane block to polyspermy in mammalian eggs. This will include a summary of classical studies that provide evidence for this block in mammalian eggs, assays used to study the mammalian membrane block and what has been elucidated from recent experimental studies about the cellular signalling events that lead to membrane block establishment and the mechanism of how the membrane block may prevent additional fertilisation.

Original languageEnglish (US)
Pages (from-to)53-61
Number of pages9
JournalReproduction, Fertility and Development
Issue number1-2
Publication statusPublished - 2006


ASJC Scopus subject areas

  • Animal Science and Zoology
  • Reproductive Medicine
  • Developmental Biology
  • Endocrinology

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