THE INHERITANCE OF GLUCOSURIA IN THE KK AND Ay MOUSE

Abstract

Both the KK and the Ay mouse exhibit many symptoms of diabetes. Glucosuria is the most satisfactory test for this condition in mice. Glucosuria is inherited as a dominant in both strains, but many factors reduce its penetrance. The penetrance in the KK strain can be increased from 23 to 62% by crossing to C57BL/10J and then selecting the most effective background modifiers. The number of modifiers must be small because response was rapid and fixation fast. The cross KK × Ay gives yellow and black offspring in equal numbers. The yellows have the dominant genes for glucosuria from both strains, and the males all become glucosuric by the time they are 8 months old, in comparison to 7% of the males in the parental yellow strain. Of the yellow females, 88% are glucosuric by 1 year in comparion to 0% of the yellow strain or 2% of the KK's. The black males which lack the gene from the Ay strain but do have the gene from the KK have no glucosurics at 8 months and only 2% at 1 year. The F1 of the cross KK × Ay provides valuable research material since all yellow males will become glucosuric by 8 months of age and none of their black litter mates will.