To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 1 Confocal 3D rendering of two fin ray segments. 3D movie of Alizarin Red stained fin rays illustrates two consecutive segments in one hemiray that possess a concave shape. A regulatory pathway involving retinoic acid and calcineurin demarcates and maintains joint cells and osteoblasts in regenerating fin Stephanie C. McMillan, Jing Zhang, Hue-Eileen Phan, Shirine Jeradi, Leona Probst, Matthias Hammerschmidt, and Marie-Andrée Akimenko Development 2018. 145:None-None; doi: 10.1242/dev.161158 Download Original Video