Fertilization: a sperm’s journey to and interaction with the oocyte
Masahito Ikawa, … , Adam M. Benham, Masaru Okabe
Masahito Ikawa, … , Adam M. Benham, Masaru Okabe
Published April 1, 2010
Citation Information: J Clin Invest. 2010;120(4):984-994. https://doi.org/10.1172/JCI41585.
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Review Series

Fertilization: a sperm’s journey to and interaction with the oocyte

Abstract

Mammalian fertilization comprises sperm migration through the female reproductive tract, biochemical and morphological changes to sperm, and sperm-egg interaction in the oviduct. Recent gene knockout approaches in mice have revealed that many factors previously considered important for fertilization are largely dispensable, or if they are essential, they have an unexpected function. These results indicate that what has been observed in in vitro fertilization (IVF) differs significantly from what occurs during “physiological” fertilization. This Review focuses on the advantages of studying fertilization using gene-manipulated animals and highlights an emerging molecular mechanism of mammalian fertilization.

Authors

Masahito Ikawa, Naokazu Inoue, Adam M. Benham, Masaru Okabe

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Figure 1

Mechanism of sperm-egg interaction.

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Mechanism of sperm-egg interaction. Over the nucleus of each mammalian s...
Over the nucleus of each mammalian sperm is a membranous sac known as the acrosome, which is filled with many kinds of hydrolytic enzymes. In the female reproductive tract or in an IVF medium, sperm undergo capacitation, which permits the acrosome reaction. Near the eggs, probably stimulated by the cumulus cells and the ZP, sperm release their acrosomal contents by exocytosis and penetrate the ZP. Only acrosome-reacted sperm fuse with eggs, but their competency for fusion does not last long. Cumulus cells are packed together by hyaluronic acid at ovulation and become diffuse during fertilization. PVS, perivitelline space.