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 anomaly in the process in which a relatively unspecialized cell acquires specialized features of a myotube cell; myotube differentiation starts with myoblast fusion and the appearance of specific cell markers (this is the cell development step); then individual myotubes fuse to form bigger myotubes and start to contract