To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S1. Sperm from +/+ males in the bursa copulatrix; sperm were observed in 0.85% NaCl within 5 min of dissection. Scale bar, 50 μm. Dimorphic sperm formation by Sex-lethal Hiroki Sakai, Hiroyuki Oshima, Kodai Yuri, Hiroki Gotoh, Takaaki Daimon, Toshinobu Yaginuma, Ken Sahara, and Teruyuki Niimi PNAS. 2019. 116:10412-10417 DOI: 10.1073/pnas.1820101116 Download Original Video Browse All Videos »