Strongylocentrotus purpuratusSea UrchinsStrongylocentrotusOvumFertilizationEmbryo, NonmammalianEchinodermataMolecular Sequence DataBase SequenceGene Expression Regulation, DevelopmentalAmino Acid SequenceBlastulaStrongyloideaPhylogenyHyalinGenesCloning, MolecularSpermatozoaSperm TailEctodermDNAGastrulaFlavobacteriaceaeSperm-Ovum InteractionsNucleic Acid HybridizationGenomeEgg ProteinsLarvaAcrosomeZygoteSequence Homology, Amino AcidGenes, RegulatorTubulinSequence AlignmentIn Situ HybridizationDNA, ComplementarySequence Analysis, DNASpecies SpecificityChromosomes, Artificial, BacterialHistonesEndodermRNA, MessengerEvolution, MolecularActinsMultigene FamilyRegulatory Sequences, Nucleic AcidSeawaterBlastocystMolecular WeightTranscription, GeneticMesoderm