To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 2. Ultrastructure of spermatid and spermatozoon. RGs are darkly stained small granules dispersed in spermtid. MIG-23 is involved in sperm migration by modulating extracellular ATP levels in Ascaris suum Qiushi Wang, Ruijun He, Lianwan Chen, Qi Zhang, Jin Shan, Peng Wang, Xia Wang, and Yanmei Zhao Development 2022. 149:None-None; doi: 10.1242/dev.200478 Download Original Video