Electrophoretic variants in erythrocytes of the house mouse, Mus musculus

Using starch-gel electrophoresis and appropriate stain­ ing, four variants have been found in erythrocytes from.the house mouse, Mus muscuius. An allele, designated Es-3 , controlling the presence of a fast-migrating esterase (designated Es-3d) has been found at the Es-3 locus. Tests of substrate specificity, heat sensitivity, and of eserine sulphate and iodoacetamide sensitivity, showed Es-3d and two other esterases (Es-3b and Es-3c) controlled by the Es-3 locus to react identically. j The frequency of Es-3 is low (0.02 0.05) in natural popu­ lations of the house mouse. It is suggested that amino acid substitutions at one site of the protein could account for the electrophoretic patterns of Es-3b, Es~3c, and Es~3d. By carrying out starch-gel electrophoresis in Irismaleate-NaOK buffer, pH 7.0, an improved resolution of house mouse hemoglobin has been obtained. The binding of maleate to a free -SH group on the diffuse hemoglobin is postulated to be the cause for the charge difference between diffuse and single hemoglobins. Several hypothesis are presented as explanations for the electrophoretic patterns observed when diffuse hemoglobin is mixed with various sulfhydryl