Msps protein is localized to acentrosomal poles to ensure bipolarity of Drosophila meiotic spindles

The female meiotic spindle is commonly formed in a centrosome-independent manner. Here we report the identification of proteins at acentrosomal poles in the female meiotic spindle of Drosophila, The acentrosomal poles contain at least two proteins, Mini-spindles (Msps) and D-TACC, which are also associated with mitotic centrosomes. These proteins interact with one another and are both required for maintaining the bipolarity of acentrosomal spindles. The polar localization of Msps is dependent on D-TACC and Ncd, a kinesin-like microtubule motor. We propose that the polar localization of Msps mediated by D-TACC and Ncd may be crucial for the stabilization of meiotic spindle bipolarity.