The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
A calculated measurement in which the weight of one or both testes, the paired egg-shaped glands normally situated in the scrotum, in which the spermatozoa develop, is divided by the total body weight of the organism and the result presented as a ratio, fraction, quotient or percentage thus normalizing it to body weight and, by extension, to the size of the organism.