title: Transfer of oocyte membrane fragments to fertilizing spermatozoa.
abstract: Several families of molecules are implicated in the membrane fusion process between sperm and oocyte. Among these, CD9 tetraspanin, a membrane-organizing molecule, plays a crucial role, since the fertilizing ability of CD9-/- oocytes is dramatically impaired. CD9 controls alpha6-beta1 integrin relocation involved in the membrane reorganization that occurs on oocyte fertilization but is not expressed on sperm. We report here that, together with several other proteins, the CD9 tetraspanin is transferred from the oocyte to the fertilizing spermatozoa present in the perivitelline space before fertilization. Transfer of CD9 from oocyte to sperm from CD9-/- male mice still occurs. CD9 acquisition by sperm results from a transfer of membrane fragments from the plasma membrane of the oocyte, in a process similar to trogocytosis, the recently described mechanism of intercellular exchange of membrane patches. Acquisition of CD9 by the sperm may be crucial for the membrane reorganization in sperm required for fusion with the oocyte, a process that is similar to the role CD9 plays in oocyte membrane reorganization.
authors.affiliation: Université Paris 13, UFR SMBH, Laboratoire de Biologie de la Reproduction, and AP-HP Hôpital Jean Verdier, Bondy, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Barraud-Lange
authors.forename: Nathalie
authors.initials: N
authors.lastname: Naud-Barriant
authors.forename: Morgane
authors.initials: M
authors.lastname: Bomsel
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Wolf
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ziyyat
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000502:physiology; D002462:Cell Membrane; D005260:Female; D005306:Fertilization; D008297:Male; D008561:Membrane Fusion; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009865:Oocytes; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology*; D060245:Tetraspanin 29
chemical_list: D015703:Antigens, CD; C554870:Cd9 protein, mouse; D008562:Membrane Glycoproteins; D060245:Tetraspanin 29