Fig. 4

Eg5 inhibition led to monopolar spindles and cell cycle arrest at metaphase in GC-2 spd cells. a Representative images of the immunofluorescence of Eg5 proteins (green), β-tubulin (red) and DAPI (blue) in the cultured GC-2 spd cells. Co-localization analyses were shown by line scanning across the representative images. Scale bar, 10 μm. b The GC-2 spd cells were incubated with 1 μM STLC for 14 h, leading to the monoastral spindles and specific spindles at metaphase. DAPI, blue; β-tubulin, green. Scale bar, 10 μm. c The ratios of abnormal cells in metaphase in the Control, 14 h STLC and 48 h STLC groups (Control, 0.49 ± 0.49%; 14 h, 16.10 ± 3.41%; 48 h, 9.86 ± 1.54%). n = 3 per group. d The ratios of monoastral spindle in the Control, 14 h STLC and 48 h STLC groups (Control, 0.24 ± 0.24%; 14 h, 14.96 ± 3.71%; 48 h, 9.05 ± 2.34%). n = 3 per group. e The ratios of specific spindles in the Control, 14 h STLC and 48 h STLC groups (Control, 0.24 ± 0.24%; 14 h, 1.15 ± 0.54%; 48 h, 0.81 ± 0.81%). n = 3 per group. Student’s t-test. Error bars, mean ± SEM. ns, p > 0.05; *, p < 0.05 and **, p < 0.01. f Graphical model of the functions of kinesin-5 Eg5 in mouse spermatocytes. In wild-type cells, the chromosomes were orderly aligned at the spindle equator at metaphase. After Eg5 inhibition, the bipolar spindle was collapsed into the monopolar spindle and the chromosomes were misaligned around the spindle poles. Two different types of the monoastral spindles were shown