Genetic relationships among 5 inbred strains established from common ancestor, dd mouse, as assessed by mandible analysis.

By multivariate analysis using mandible measurements genetic relationships were investigated among 5 inbred strains, DDD, DDK, DSD, DD/Tbr and DDY, derived from the common ancestor, dd mouse. (1) In canonical discriminant analysis (discriminant analysis with reduction of dimensionality), 3 DD strains, DDD, DSD, and DDY, were closer to one another than to any control strain on planes Z1-Z2, Z1-Z3, and Z2-Z3. Only the DDK strain was quite far from those 3 strains. (2) In the discriminant analysis, however, the 5 inbred strains could be classified correctly at the rate of 100%. They were genetically different from one another. (3) The causes for this genetical difference seemed to be the genetic heterogeneity of the ancestor dd mouse and the method of inbreeding which had been independent since the separation.