A strain that is essentially homozygous at all genetic loci. In mice, such strains are produced by brother–sister mating for at least 12 sequential generations, or more if other breeding systems are used.
A group of organisms so highly inbred as to be genetically identical, except for sexual differences.
A set of animals produced by at least 20 consecutive generations of sister x brother or parent x offspring mating and can be traced to a single ancestral pair in the 20th or subsequent generation. Animals of an inbred strain are nearly fully homozygous, which thus provides a defined and consistent genotype for analysis.