Abnormalities observed during meiosis of Mer3 spermatocytes: a spermatid containing two nuclei of equal size (arrows) and two Nebenkerns (A), tripolar spindle in a spermatocyte going through the second meiotic division (B), and four-polar spindle in a spermatocyte undergoing the second meiotic division (C-E). Panel C shows the phase contrast image, panel D the DAPI-stained nuclei, and panel E the merged image. Arrow points to the central spindle midzone . For comparison, wild-type meiotic cells in telophase were shown (F).
Dorogova et al. BMC Cell Biology 2008 9:1 doi:10.1186/1471-2121-9-1