AllantoisYolk SacExtraembryonic MembranesChorionBase PairingPrimitive StreakBase SequenceMesodermBlood VesselsEmbryo, MammalianGerm CellsEmbryonic and Fetal DevelopmentPlacentaT-Box Domain ProteinsAmnionCoturnixGene Expression Regulation, DevelopmentalIn Situ HybridizationEpitheliumGastrulaEmbryonic DevelopmentSkull BasePregnancySchiff BasesBase CompositionChick EmbryoReceptors, Growth Factor