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.
partial or complete failure of the ultimobranchial bodies to fuse with the ventral thyroid primordium; as a result, ultimobranchial bodies remain as unilateral or bilateral vesicles composed exclusively of calcitonin-producing cells