Int. J. Dev. Biol. 52: 677 - 682 (2008)
doi: 10.1387/ijdb.072528ek
© UPV/EHU Press

Sperm penetration through cumulus mass and zona pellucida

Ekyune Kim, Misuzu Yamashita, Masanori Kimura, Arata Honda, Shin-Ichi Kashiwabara and Tadashi Baba*

Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki, Japan

ABSTRACT Mammalian fertilization requires sperm to penetrate the cumulus mass and egg zona pellucida prior to fusion with the egg. Although sperm penetration through these physical barriers is essential, the molecular mechanism has not yet been completely elucidated. In addition to sperm motility, hyaluronan-hydrolyzing and proteolytic enzymes of sperm have been suggested to participate in the penetration events. Here we focus on the functional roles of hyaluronidase and protease in sperm passage through the cumulus mass and zona pellucida.

Keywords:

egg, zona pellucida, acrosome reaction, penetration, hyaluronidase, proteolysis

*Corresponding author e-mail: acroman@sakura.cc.tsukuba.ac.jp