AneuploidyOocytesMeiosisOogenesisPloidiesMetaphaseXenopus laevisFertilizationIn Vitro Oocyte Maturation TechniquesOocyte RetrievalXenopusCumulus CellsVitrificationOvumMeiotic Prophase IOocyte DonationOvaryMicroinjectionsMaturation-Promoting FactorBlastocystEmbryonic DevelopmentSpermatozoaSperm-Ovum InteractionsFertilization in VitroProto-Oncogene Proteins c-mosCryopreservationDiploidyParthenogenesisSperm Injections, IntracytoplasmicProphaseZygoteDNA, NeoplasmEmbryo TransferChromosomesOvarian FollicleZona PellucidaPregnancyCleavage Stage, OvumSpindle ApparatusKaryotypingPolyploidyNuclear Transfer TechniquesTrisomyEmbryo, MammalianChromosomal InstabilityCell NucleusStarfishPreimplantation DiagnosisImage CytometryEgg ProteinsIn Situ Hybridization, FluorescenceRNA, MessengerChromosome SegregationXenopus ProteinsCytoplasmNondisjunction, Genetic