title: Sperm attachment and penetration competence in the human oocyte: a possible aetiology of fertilization failure involving the organization of oolemmal lipid raft microdomains influenced by the ΔΨm of subplasmalemmal mitochondria.
abstract: The roles of oolemmal lipid raft microdomains enriched in the ganglioside GM1 and the tetraspanin protein CD9 were investigated as causative agents in fertilization failure in human IVF where spermatozoa progress to the oolemma but fail to attach or, if attached, to penetrate. The findings show that specific configurations of GM1 lipid raft microdomains are consistent with attachment and penetration, while microdomains composed of CD9 lipid rafts, a protein known to be critical for penetration, do not appear to have a central role in the initial stages of attachment. The relative magnitude of the potential difference across the inner membrane (ΔΨm) in mitochondria localized to a stable subplasmalemmal domain appears to influence the organization of GM1 but not CD9 lipid raft microdomains in the corresponding oolemma. The findings present a novel view of how fertilization competence may be established in the human oocyte and a means by which certain fertilization failures that occur after conventional clinical IVF can be identified and explained in the unfortunate instance of fertilization arrest at the oolemma.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, United States; Colorado Reproductive Endocrinology, Rose Medical Center, Denver, CO 80220, United States. Electronic address: jonathan.vanblerkom@colorado.edu.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Van Blerkom
authors.forename: Kyle
authors.initials: K
authors.lastname: Caltrider
mesh_terms: D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D005455:Fluorescent Antibody Technique; D005677:G(M1) Ganglioside / Q000378:metabolism; D006801:Humans; D007246:Infertility / Q000209:etiology*; D008297:Male; D021962:Membrane Microdomains / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D011247:Pregnancy; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D060245:Tetraspanin 29 / Q000378:metabolism; D015044:Zona Pellucida / Q000378:metabolism*
chemical_list: C554869:CD9 protein, human; D060245:Tetraspanin 29; D005677:G(M1) Ganglioside
keywords: CD9; GM1; fertilization; lipid rafts; mitochondria