top-2(it7ts) male germ lines have chromosome-segregation defects. Images from live analysis of N2, top-2(it7ts); him-8(e1489), and emb-27(g48) males. Males were shifted to 24° as L3s. After 16 hr, male gonads were dissected and stained with Hoechst dye (red in merged panels) and visualized by DIC optics. White arrows indicate examples of chromatin bridges and atypical chromosome segregation. The number of germ lines scored for each genotype were: N2, n = 32; top-2(it7ts), n = 25; and emb-27(g48), n=21. Bar, 5 μm.