There are a number of derivatives of straight inbred strains, and these are discussed briefly here. They are mostly used in genetical research, but may be useful in other disciplines interested in finding out what genes are responsible for phenotypic differences between inbred strains. They include the following
Sets of Recombinant Inbred Strains (RIS):
Sets of strains used for identifying and mapping loci which affect a phenotype which differs between two standard inbred strains
Sets of Recombinant Congenic Strains (RCS)
Sets of strains used for identifying and mapping quantitative trait loci which contribute to differences between two inbred strains.
Pairs of Coisogenic Strains
A pair of inbred strains which differ at only a single locus as a result of mutation or (in recent years) genetic modification of a single locus.
Segregating Inbred Strains
An isogenic strain carrying a mutation and maintained with forced heterozygosity
Pairs of Congenic Strains
A pair of strains which approximate the coisogenic state but produced by ten or more backcrosses of a mutant or GM locus to an inbred genetic background
Sets of Consomic or Chromosome Substitution Strains
Sets of inbred strains which differ from each other by a single chromosome. Useful for studying which genes affecting a trait are situated on each of the chromosomes (if a full set is available).
A pair of strains which differ only in the mitochondrial loci.