BlastodermEgg YolkYolk SacEmbryo, NonmammalianGastrulaDrosophilaBlastodiscDrosophila ProteinsDrosophila melanogasterChick EmbryoBody PatterningGene Expression Regulation, DevelopmentalTriboliumGenes, InsectVitelline MembraneCoturnixMorphogenesisInsect ProteinsHeteropteraQuailZebrafishFushi Tarazu Transcription FactorsOrganizers, EmbryonicBlastulaNodal Signaling LigandsOvumCleavage Stage, OvumInsect HormonesGerm CellsHomeodomain ProteinsEgg ProteinsGerm LayersZebrafish ProteinsEmbryonic DevelopmentTranscription FactorsIn Situ HybridizationEmbryonic InductionAminopterinMesodermEndoderm