Heterozygous males have a reduced number of sex comb teeth on the first leg. Scr1/ScrAntp-A41 males have an average of 0.3 sex comb teeth on the first leg. Scr4/ScrAntp-A41 males are recovered at 1% of expected frequency and rarely have sex comb teeth on the first legs (average is 0.08 per leg in these animals). ScrAntp-A41/ScrTpl9 males (in which the haplolethality of the Df(3R)Tpl9 chromosome has been rescued by Dp(3;3)Dfdrv1) show 13% viability and have an average of 1.8 sex comb teeth per first leg. ScrLIN/ScrAntp-A41 males have an average of 2.8 sex comb teeth on the first leg (compared to 10.8 per leg in wild type).