Genetics of two tissue esterase polymorphisms (Est-4 and Est-5) in the rabbit

Two polymorphic esterase systems were found after electrophoresis of rabbit tissue homogenates. Each of these systems is controlled by an autosomal locus with two alleles. Est-4 determines the absence (Est-4a) or presence (Est-4b) of two bands of esterase activity with intermediate anodcal mobility and broad substrate specificity. This polymorphism was found to be present in liver, small intestine, and spleen but not in kidney, heart, and testis. Est-5 is coding for cathodally migrating esterases which differ in mobility (Est-5a and Est-5b). This polymorphism was found only in kidney and testis homogenates. Est-5 esterases are more active against alpha-naphthyl acetate than against beta-naphthyl acetate and have no activity against alpha-naphthyl butyrate. Linkage analysis indicated that Est-4 is localized on rabbit LG VI as part of a cluster of esterase loci, whereas Est-5 segregates independently, Rabbits from two inbred and nine partly inbred strains were tested for these polymorphisms.