Time series of meiosis I, starting at metaphase, 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 immersion condenser, with 2.0x zoom lens. Images captured every 15 sec over 35 min using a QImaging Retigo EXi CCD camera. Raw images were processed using 5-frame algorithm (Shribak and Oldenbourg, 2003). A movie of the series is included in this grouped set.