Figure 9.

RNAi directed against endogenous CHO1 interferes with the organization of central spindle and the formation of midbody matrix in CHO cells. Mock- and siRNA-transfected cells were synchronized and fixed at the different stages of mitosis 30 h after transfection. Cells were visualized by staining with antitubulin (A–H), anti-CHO1 polyclonal (A′-H′) antibodies, and DAPI (A"-H"). To correctly represent the amount of endogenous CHO1 in all cells, both mock- and siRNA-transfected cells were fixed and immunostained in an identical manner, and all images were captured and developed using identical exposure and conditions. RNAi directed against endogenous CHO1 affects neither the formation of bipolar spindle (B–B") nor chromosome segregation (D", E", G", and H") in CHO cells. However, the reduced level of CHO1 expression (D′ and G′) diminishes the matrix formation in anaphase (arrowhead in D) and telophase (arrowhead in G) cells in comparison with control (arrows in C and F). Almost complete depletion of CHO1 (E′ and H′) causes the severe disorganization of central spindles (E and H).