“…Importantly, among the signaling pathways controling bone patterning, such as during limb development (Capdevila and Belmonte, 2001; Riddle et al, 1993), Sonic hedgehog (Shh) has been described as a key factor controling ray bifurcation during fin regeneration (Armstrong et al, 2017; Laforest et al, 1998). However, repetitive amputations (Azevedo et al, 2012), macrophage activity (Petrie et al, 2014), actinotrichia organization (Nakagawa et al, 2022), and hydrodynamics (Dagenais et al, 2021) are able to alter the proximo-distal position of ray branchpoints through apparently Shh-independent mechanisms. Thus, the formation and shaping of bifurcated bony structures and the cellular contribution to these processes remain unclear.…”