Hemizygous male larvae are sensitive to methyl methanesulfonate (MMS). They show sensitivity to ultra violet (UV) light and X rays. Sensitivity to MMS is recessive at 0.075% MMS and shows a strong semidominant effect at 0.125% MMS. Only 3.8% of eggs laid by homozygous females develop into adults that eclose.
Separable from: a second site lethal mutation. The lethality of the chromosome can be separated from the mei-41 locus by recombination.