Sperm penetration through cumulus mass and zona pellucida.
نویسندگان
چکیده
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.
منابع مشابه
A hyaluronidase activity of the sperm plasma membrane protein PH-20 enables sperm to penetrate the cumulus cell layer surrounding the egg
A typical mammalian egg is surrounded by an outer layer of about 3,000 cumulus cells embedded in an extracellular matrix rich in hyaluronic acid. A current, widely proposed model is that the fertilizing sperm, while it is acrosome intact, passes through the cumulus cell layer and binds to the egg zona pellucida. This current model lacks a well-supported explanation for how sperm penetrate the c...
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Fertilization involves several precisely coordinated steps, including sperm dispersal of the oocyte cumulus mass, adhesion and binding to the zona pellucida, penetration through the zona pellucida, and fusion with the oocyte. Hyaluronidase, which is present in the sperm head, is known to be essential for the decomposition of the oocyte cumulus mass. Interestingly, two types of hyaluronidase—SPA...
متن کاملMost fertilizing mouse spermatozoa begin their acrosome reaction before contact with the zona pellucida during in vitro fertilization.
To fuse with oocytes, spermatozoa of eutherian mammals must pass through extracellular coats, the cumulus cell layer, and the zona pellucida (ZP). It is generally believed that the acrosome reaction (AR) of spermatozoa, essential for zona penetration and fusion with oocytes, is triggered by sperm contact with the zona pellucida. Therefore, in most previous studies of sperm-oocyte interactions i...
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F or successful mammalian fertilization, sperm penetrate the outer investments of female gametes in the ampulla of the oviduct and fuse with the egg plasma membrane. The “fertilizing” sperm traverse the cumulus mass surrounding ovulated eggs, bind temporarily, and then penetrate through the zona pellucida, a structured extracellular glycomatrix, to enter into the perivitelline space (Fig. 1A). ...
متن کاملIdentification of a hyaluronidase, Hyal5, involved in penetration of mouse sperm through cumulus mass.
A glycosylphosphatidylinositol (GPI)-anchored hyaluronidase, PH-20, on the sperm surface has long been believed to assist sperm penetration through the cumulus mass surrounding the eggs. However, mouse sperm lacking PH-20 were still capable of penetrating the cumulus mass despite a delayed dispersal of cumulus cells. Intriguingly, a 55-kDa hyaluronan-hydrolyzing protein was abundantly present i...
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عنوان ژورنال:
- The International journal of developmental biology
دوره 52 5-6 شماره
صفحات -
تاریخ انتشار 2008