Figure 11.

Spindle assembly. Because meiotic spindles in Drosophila are acentriolar, spindle assembly is organized by the chromosomes. The chromosomal passenger complex proteins Aurora-B and Incenp (teal), as well as Subito (green) and the Centralspindlin complex (blue), localize to the central spindle around the DNA and function in chromosome movement and/or spindle assembly/stabilization. Nod (brown arrowhead) acts as the polar ejection force to push chromosomes away from the spindle poles. The proteins MSPS and D-TACC (pink) function at the spindle poles to maintain spindle bipolarity. The Augmin complex (purple) is also located predominately at the spindle poles, where it recruits γ-tubulin and promotes spindle assembly. Both γ-tubulin (dashed lines) and α/β-tubulin (dotted lines) localize along the entire meiotic spindle. The kinesins Ncd and KLP10A, as well as additional kinesins, help regulate the assembly (Ncd) and disassembly (KLP10A) of the bipolar spindle. Mei-38 promotes the assembly or stabilization of kinetochore microtubules (solid lines).