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.
stretched or widened aperture of the luminal space of one or more of the vessels formed within the six (five in mammals) pairs of branchial arches in embryogenesis; in the adult, some of these vessels give rise to the great vessels