Fig. 3. asp^dd4 meiocytes show well defined spindle poles and a range of central spindle defects. (A,B) Centrin (red in merged image and monochrome in central panels) is seen in a typical V-shaped pattern corresponding to adjacent centrioles at the spindle poles (A). The telophase tetrapolar cell in (B) shows no organisation of a central spindle. It has failed to undergo cytokinesis in meiosis I and appears set to fail the second meiotic division. (C) A cyst stained to reveal - tubulin (red in merged image, and monochrome in central panel). This illustrates the variation in the extent of formation of central spindle structures with this mutant allele. Central spindle structures are missing in several cells of the cyst. In this panel, three cells with central spindle structures are shown — in one it is poorly formed (small arrow), in another it is displaced (mid-sized arrow) and in the third it is comparable to wild type (large arrow). In all cases the merged image shows DNA in blue and microtubules in green. The corresponding monochrome images of microtubules are also shown in the bottom panels. (D) A cyst stained to reveal centrosomin (red in the merged image, and monochrome in the central panel). The arrowhead points to a cell lacking central spindle structure.