[Esterase XX. Disc-electrophoretic investigations on the polymorphism of the esterases of the house mouse (author's transl)].

For the further clarification of the polymorphism of mouse-esterase and its hormonal control, which in part have not yet been fully comprehended, disc-electrophoretic analyses of eight organs were made, using a strain with the Tfm-mutation. In addition, quantitative assays of esterase activity as well as histochemical studies were performed. The individual organs are characterized by a specific banding pattern of esterase, which is essentially conditioned by the diverse activity of a limited number of bands. Partly these may be regarded as primary gene products, partly they seem to be secondary modifications. The few incidences of band-linkage justify the expectations, that further gene loci will be discovered. In four organs of Tfm-mutants a lower esterase activity was found than in the controls, which was especially distinct in the kidney. The behaviour of the testosterone-dependent bands in the kidneys of Tfm-mutants seems to indicate two different mechanisms of the effect of testosterone on these bands.