This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bedford, J. M. Articles by Oda, S. Search for Related Content PubMed PubMed Citation Articles by Bedford, J. M. Articles by Oda, S.

The unusual state of the cumulus oophorus and of sperm behaviour within it, in the musk shrew, Suncus murinus

In the musk shrew, Suncus murinus, the behaviour of the cumulus—egg complex and its interaction with spermatozoa were unusual in several respects. The cumulus oophorus was ovulated about 15.5 h after mating or treatment with hCG as a hyaluronidase-insensitive matrix-free ball of cells which remained for relatively long periods of about 14 h around fertilized, and for about 24 h around unfertilized eggs. As a probable function of the small number of up to about 10 or 20 spermatozoa that' generally reached the oviduct ampulla from isthmic crypts, there was often a delay of up to 10 h after ovulation before most eggs were penetrated. Soon after ovulation, however, the corona radiata retreated progressively from the zona pellucida, creating a closed perizonal space within the cumulus oophorus. Usually, most spermatozoa that did reach the ampulla were found within a cumulus and generally within that perizonal space. However, whereas the acrosome was intact among the few free ampullary spermatozoa, and in those adhering to the zona of cumulus-free eggs after delayed mating, all spermatozoa seen moving within the cumulus or adhering to the zona of unfertilized eggs had shed the giant acrosome. In accord with current observations in other shrews, the cumulus in Suncus may therefore function not only to sequester spermatozoa, but also as an essential mediator of fertilization – probably by inducing the acrosome reaction. In the absence of the acrosomal carapace that expresses the zona receptors in most mammals, fertilizing Suncus spermatozoa could use an unusual array of barbs on the exposed perforatorium to attach to the zona pellucida.

This article has been cited by other articles:

				T. Kaneko, H. Iida, J. M. Bedford, and T. Mori Spermatozoa of the Shrew, Suncus murinus, Undergo the Acrosome Reaction and Then Selectively Kill Cells in Penetrating the Cumulus Oophorus Biol Reprod, August 1, 2001; 65(2): 544 - 553. [Abstract] [Full Text] [PDF]

				J.M. Bedford Mammalian Fertilization Misread? Sperm Penetration of the Eutherian Zona Pellucida Is Unlikely to be a Lytic Event Biol Reprod, December 1, 1998; 59(6): 1275 - 1287. [Full Text]