Both l(2)41Aa^IR18/Df(2R)B and l(2)41Aa^IR18/Df(2R)Rsp31 mutant larvae exhibit reduced wing discs. The total number of Df(2R)Rsp31/l(2)41Aa^IR18 larval neuroblast cells undergoing mitosis is reduced compared to wild-type cells (mitotic index of 0.39 vs 0.81). The number of l(2)41Aa^IR18/l(2)41Aa¹ cells undergoing mitosis is likewise reduced (mitotic index of 0.5). 62% of l(2)41Aa^IR18/Df(2R)B mutant larval spermatids carry micronuclei, while 10% of l(2)41Aa^IR18/l(2)41Aa¹ mutants exhibit this effect. A fraction of spermatids have large Nebenkerns associated with either two or four nuclei or micronuclei (44% in l(2)41Aa^IR18\Df(2R)B mutants and 4% in l(2)41Aa^IR18\l(2)41Aa¹ mutants). In 60% of l(2)41Aa^IR18/Df(2R)B mutant larval spermatids, bivalents do not condense properly and chromatin filaments are visible along the three major dots of chromatin; this effect was also seen in 10% of l(2)41Aa^IR18/l(2)41Aa¹ mutants. Chromatin bridges are visible connecting the two sets of chromosomes during anaphase I of spermatid meiosis in l(2)41Aa^IR18/Df(2R)B mutants. Chromosome segregation is also altered in these mutants, with 62% of chromosomes lagging at anaphase/telophase I. In l(2)41Aa^IR18/l(2)41Aa¹ mutants, 15% of chromosomes are seen to be lagging. Lagging chromosomes are also observed during anaphase/telophase II, with a frequency of 54% in l(2)41Aa^IR18/Df(2R)B mutants and 14% in l(2)41Aa^IR18/l(2)41Aa¹ mutants.