Movie of meiosis I in primary spermatocytes of the crane-fly Nephrotoma suturalis that have been experimentally flattened. Time-lapse polarization microscopy using a Nikon Microphot SA, equipped for liquid crystal polarized light microscopy (LC-PolScope, CRi, Woburn Massachusetts) 60x/1.4 PlanApo oil immersion objective, 1.4 NA oil imm. condenser, with 2.0x zoom lens. Images captured every 30/60/90 sec for 2 hr 31 min using a QImaging Retigo EXi CCD camera. Raw images were processed using a 5-frame algorithm (Shribak and Oldenbourg, 2003). The time series used for the movie is included in this grouped set.