Phosphorylation dynamics in male meiosis: MPM-2 colocalization with microtubule cytoskeleton.

Single and double labelling in meiocytes was set up with MPM-2 and anti-alfa-tubulin antibodies in a wild-type clone of Solanum and in a male-sterile mutant (SH9B) with severe alterations in microsporogenesis. Anti-MPM-2 antibody dynamically marked all meiotic stages, showing a similar pattern of distribution in both meiosisI and II. The experiments of double labelling proved that MPM-2 colocalizes with the typical MT arrays, such as spindles, interzonal MTs, RMSs and phragmoplasts. Furthermore, MPM-2 is localized in the nuclei at the stage when the nuclear envelope has the presumptive role of MTOC.