Yolk SacEgg YolkEndodermal Sinus TumorVitelline MembraneMesonephromaEndolymphatic SacAir SacsEndodermEmbryo, MammalianAnal SacsGestational SacHematopoiesis, ExtramedullaryEmbryonic and Fetal DevelopmentPregnancyalpha-FetoproteinsPinocytosisPlacentaExtraembryonic MembranesPovidoneDysgerminomaEgg ProteinsHematopoietic Stem CellsGestational AgeGene Expression Regulation, DevelopmentalFetusPregnancy Trimester, FirstAmnionEmbryo LossBlood VesselsHematopoiesisTeratomaMesonephrosErythropoiesisEmbryonic DevelopmentTesticular NeoplasmsChick EmbryoNeoplasms, Germ Cell and EmbryonalHematopoietic SystemErythroblastsCell Differentiation