Strongylocentrotus purpuratusSea UrchinsStrongylocentrotusOvumEchinodermataFertilizationEmbryo, NonmammalianStrongyloideaBlastulaHyalinMolecular Sequence DataEctodermSperm TailSpermatozoaBase SequenceGene Expression Regulation, DevelopmentalGastrulaAmino Acid SequenceSperm-Ovum InteractionsPhylogenyGenesGenomeCloning, MolecularEgg ProteinsLarvaAcrosomeGenes, RegulatorSequence Homology, Amino AcidZygoteTubulinNucleic Acid HybridizationSequence AlignmentIn Situ HybridizationDNA, ComplementarySpecies SpecificityChromosomes, Artificial, BacterialHistonesEvolution, MolecularEndodermDNAActinsRNA, MessengerMultigene FamilyRegulatory Sequences, Nucleic AcidSeawaterBlastocystMolecular WeightTranscription, GeneticMesodermTranscription FactorsSequence Homology, Nucleic AcidSequence Analysis, DNAKelpRepetitive Sequences, Nucleic AcidTissue DistributionGene Expression RegulationProteinsCalciumWater Movements