mus102^A1/Y larvae are more sensitive to formaldehyde than wild-type. mus102^A1/mei-41^AI male larvae are more sensitive to formaldehyde than wild-type.

Homozygotes and hemizygotes show a higher frequency of spontaneous chromosome aberrations in neuroblast metaphases than wild-type larvae. The ratio of chromatid breaks to isochromatid breaks is 1.2-1.4. Approximately half of the breaks are heterochromatic and half are euchromatic. The breaks appear to be randomly distributed among the chromosomes. Breaks are 1.4-1.6 times more frequent in females than in males.

Hemizygous male larvae are sensitive to methyl methanesulfonate (MMS). They show resistance to ultra violet (UV) light and X rays that is similar to wild-type. 65.8% of eggs laid by homozygous females develop into adults that eclose. mei-41^A1 mus102^A1 double mutant larvae have a greatly increased sensitivity to MMS compared to either single mutant. An increase compared to wild type in X chromosome loss due to non-disjunction is seen in the progeny of homozygous females.