ET3/Ednrb2 signaling is critically involved in regulating melanophore migration in Xenopus.

Melanoblasts are derived from neural crest cells (NCCs) and are the only NCCs that migrate through the dorsolateral pathway. However, how melanoblasts evolved to migrate through a pathway different from other NCCs is still unclear, because little is known about common molecular mechanisms of melanoblast migration that are conserved between species. Endothelin receptor B2 (Ednrb2) is required for avian melanoblasts to enter the dorsolateral pathway. Here, we show that Endothelin-3 (ET3)/Ednrb2 signaling is also required for melanoblast migration in Xenopus laevis, although they migrate through the ventral pathway. In Xenopus, Ednrb2 is expressed by melanoblasts from pre-migration stages and ET3 is expressed around their destinations, suggesting that ET3/Ednrb2 signaling may determine melanophore localization. Furthermore, melanoblast migration is interrupted by aberrant ET3/Ednrb2 signaling in vivo and their invasive ability is enhanced by ET3 in vitro. Our results suggest that ET3/Ednrb2 signaling is required for melanoblast migration in Ednrb2 gene-conserved animals.