Hmt4-20174 mutants (Df(1)174 homozygotes carrying skpA+t4) are viable and fertile. The hatch rate of embryos is only approximately 60% that of wild type. Survival of these animals in response to exposure to hydroxyurea or methylmethanesulfonate is normal.
Hmt4-20174 mutants (Df(1)174 homozygotes carrying skpA+t4) show a decrease in the mitotic index after γ-irradiation, similar to that seen in wild-type flies.