bk1 << l(2)41Aa << rl << bk2
Df(2R)IR7/Df(2R)B mutant larvae have abnormal wing discs. Df(2R)B/Df(2R)IR7 mutant larval neuroblast cells exhibit a higher anaphase/metaphase ratio than wild-type cells. The total number of Df(2R)B/Df(2R)IR7 larval neuroblast cells undergoing mitosis is reduced compared to wild-type cells (mitotic index of 0.41 vs 0.81). 25% of Df(2R)B/Df(2R)IR7 mutant larval spermatids carry micronuclei. 12% of Df(2R)IR7/Df(2R)B mutant larval spermatids have large Nebenkerns associated with either two or four nuclei or micronuclei. In 30% of Df(2R)IR7/Df(2R)B mutant larval spermatids, bivalents do not condense properly and chromatin filaments are visible along the three major dots of chromatin. In Df(2R)B/Df(2R)IR7 mutant larval spermatids, 28% of chromosomes are seen to be lagging during anaphase/telophase I, while 21% lag during anaphase/telophase II.