part of part of hypoblast (generic) http://upload.wikimedia.org/wikipedia/commons/e/e3/Gray21.png https://github.com/obophenotype/uberon/issues/437 https://sourceforge.net/p/geneontology/ontology-requests/9676/ BTO:0003953 UMLS:C1512561 TODO - consider relationship to UBERON:0000091 ! bilaminar disc mesendoderm NCIT:C34190 hypoblastus UBERON:0000089 XAO:0003044 FMA:293873 Wikipedia:Hypoblast EFO:0001930 In mammal and avian, extraembryonic endoderm such as visceral endoderm and hypoblast play essential roles in the embryonic axis formation and germ layer development. These extraembryonic tissues are generally considered to have been created in ancestral amniotes evolved from the Xenopus-type ancestor (reference 1); The endomesoderm secretes as yet unidentified signals that posteriorize the ectoderm, which would otherwise adopt an anterior fate. Our results point to a conserved function at the base of deuterostomes for beta-catenin in germ layer specification and to a causal link in the definition of the posterior part of the embryonic ectoderm by way of activating posteriorizing endomesodermal factors (reference 2).[well established][VHOG] hypoblast AAO:0010619 A primary germ layer that can give rise to both mesoderm and endoderm.[AAO] MIAA:0000418 Missing definition for term UBERON:0000089. Please replace it using linked reference. ZFA:0000117 AAO:0000229 future endoderm and mesoderm VHOG:0001222 MAT:0000418 this term groups together disparate structures with different relationships. EMAPA:32762 The inner of the two layers of the blastoderm that forms during gastrulation and give rise to the definitive mesoderm and endoderm. Kimmel et al, 1995.[TAO] endomesoderm TAO:0000117 embryonic structure blastoderm