Deoxyribonuclease II (DNase II) activity is regulated systemically by a single locus in mice.

A survey of inbred strains of mice revealed genetic variation in DNase II activity in the spleen, liver, kidney, lung, heart, coagulating gland and preputial gland. Since DNase II activities in these tissues were closely correlated to each other, systemic regulation of the enzyme was suggested. The inheritance of quantitative variation in the DNase II activity was studied in a test cross using the spleen DNase II activity level as an indicator of progeny phenotypes. The results showed that the strain difference in DNase II activity was controlled by a single autosomal locus. The locus for the mouse DNase II activity level, designated as Dnl2al, had at least two alleles. The allele Dnl2ala determines high DNase II activity and occurs in C57BL/6 and C3H/He strains. The other allele Dnl2alb determines low enzyme activity and occurs in BALB/c and DBA/2 strains.