Role of sperm alphavbeta3 integrin in mouse fertilization.
Oocyte integrins have been described as essential for fertilization. But this concept has been challenged by deletion experiments. Recently, we have shown that sperm integrin alpha6beta1 plays a determinant role in mouse gamete interaction. In this study, we demonstrate the presence of alphavbeta3 integrin by Western blot and immunofluorescence on the sperm membrane. Oocytes and/or sperm preincubations with anti-alphav or anti-beta3 antibodies were performed before in vitro fertilization on cumulus-intact and zona-free egg assays. We observed inhibitory effects on the fusion process mostly by means of sperm function. An antibody directed against vitronectin inhibited gametes fusion, whereas the presence of exogenous vitronectin increased its efficiency. We suggest that vitronectin (on multimeric forms) can play a first nonspecific link corresponding to loosely bound spermatozoa to oocyte and that this link could be mediated by means of oocyte proteoglycans or integrins, and sperm alphavbeta3 integrin.
Université Paris Descartes, Laboratoire Interaction Gamétique et Fusion des Membranes, EA 2717, Institut Alfred Jost, Service d'Histologie Embryologie Biologie de la Reproduction, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France.
Céline Chalas
CC
Boissonnas
Debbie
D
Montjean
Corinne
C
Lesaffre
Jana
J
Auer
Daniel
D
Vaiman
Jean-Philippe
JP
Wolf
Ahmed
A
Ziyyat
D000818:Animals; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D008024:Ligands; D008297:Male; D008566:Membranes / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D009865:Oocytes / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism*; D019096:Vitronectin / Q000096:biosynthesis
D039302:Integrin alphaVbeta3; D008024:Ligands; D019096:Vitronectin