Sperm-egg interaction and fusion represent a key moment of fertilization. In mammals, it is not possible without the interaction of the tetraspanin superfamily proteins including CD81. A detailed immunohistochemical localization of CD81 was monitored in bovine oocytes during different maturation stages, as well as during early embryogenesis. In addition, characterization of CD81 was carried out in bovine and mouse sperm. In bovine eggs, CD81 was detected on the plasma membrane of the germinal vesicle, metaphase I and metaphase II oocytes. During fertilization, accumulation of CD81 molecules in the perivitelline space of fertilized oocytes, which appeared as vesicles associated with plasma membrane, was observed. In majority of bull-ejaculated sperm and caput, corpus and cauda epididymal sperm, as well as mouse cauda epididymal sperm, CD81 was found on the plasma membrane covering the apical acrosome. Although the process of capacitation did not influence the localization of CD81, it was lost from the surface of the acrosome-reacted spermatozoa in bull, in contrast to mouse sperm where there was a relocalization of the CD81 protein during acrosome reaction across the equatorial segment and later over the whole sperm head. The presented results highlight conservative unifying aspects of CD81 expression between cattle and mouse, together with mouse-specific traits in sperm CD81 behaviour, which emphasizes certain species-specific mechanisms of fertilization to be considered.

• MeSH
• akrozomální reakce MeSH
• antigeny CD81 metabolismus   MeSH
• fertilizace in vitro MeSH
• interakce spermie a vajíčka MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• oocyty cytologie   metabolismus   MeSH
• skot MeSH
• spermie cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH