The Mouse Adult Gross Anatomy Ontology and Mammalian Phenotype Ontology are downloaded weekly from the Mouse Genome Informatics databases at Jackson Laboratories (ftp://ftp.informatics.jax.org/pub/reports/index.html). For more information about these ontologies, see the MGI Publications Page at http://www.informatics.jax.org/mgihome/other/publications.shtml.
any structural anomaly of the horseshoe-shaped thickening of the endoderm at the cranial (rostral) end of the primitive streak formed by the involution of Spemann's organizer cells which, together with the notochord, induces the formation of the neural plate from the overlying ectodermal cells and contributes mesodermal type cells to the surrounding tissue