title: New insights into the mechanisms of fertilization: comparison of the fertilization steps, composition, and structure of the zona pellucida between horses and pigs.
abstract: The mechanism of fertilization remains largely enigmatic in mammals. Most studies exploring the molecular mechanism underlying fertilization have been restricted to a single species, generally the mouse, without a comparative approach. However, the identification of divergences between species could allow us to highlight key components in the mechanism of fertilization. In the pig, in vitro fertilization (IVF) and polyspermy rates are high, and spermatozoa penetrate easily through the zona pellucida (ZP). In contrast, IVF rates are low in the horse, and polyspermy is scarce. Our objective was to develop a comparative strategy between these two divergent models. First, we compared the role of equine and porcine gametes in the following five functions using intraspecific and interspecific IVF: ZP binding, acrosome reaction, penetration through the ZP, gamete fusion, and pronucleus formation. Under in vitro conditions, we showed that the ZP is a determining element in sperm-ZP attachment and penetration, whereas the capacity of the spermatozoa is of less importance. In contrast, the capacity of the spermatozoa is a key component of the acrosome reaction step. Second, we compared the composition and structure of the equine and porcine ZP. We observed differences in the number and localization of the ZP glycoproteins and in the mesh-like structure of the ZP between equine and porcine species. These differences might correlate with the differences in spermatozoal attachment and penetration rates. In conclusion, our comparative approach allows us to identify determining elements in the mechanism of fertilization.
authors: Institut National de la Recherche Agronomique, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.
authors: Sylvie
authors: S
authors: Mugnier
authors: Maria Elena
authors: ME
authors: Dell'Aquila
authors: Jesus
authors: J
authors: Pelaez
authors: Cécile
authors: C
authors: Douet
authors: Barbara
authors: B
authors: Ambruosi
authors: Teresa
authors: T
authors: De Santis
authors: Giovanni Michele
authors: GM
authors: Lacalandra
authors: Claude
authors: C
authors: Lebos
authors: Pierre-Yves
authors: PY
authors: Sizaret
authors: Bernadette
authors: B
authors: Delaleu
authors: Philippe
authors: P
authors: Monget
authors: Pascal
authors: P
authors: Mermillod
authors: Michèle
authors: M
authors: Magistrini
authors: Stuart A
authors: SA
authors: Meyers
authors: Ghylène
authors: G
authors: Goudet
mesh_terms: D000818:Animals; D004527:Egg Proteins / Q000378:metabolism; D005260:Female; D005307:Fertilization in Vitro; D006736:Horses / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009865:Oocytes / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D013075:Sperm Capacitation; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology*; D013552:Swine / Q000502:physiology*; D015044:Zona Pellucida / Q000502:physiology*; D000072216:Zona Pellucida Glycoproteins
chemical_list: D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins