The mutated in molorectal cancer (Mcc) gene has been described as a tumour suppressor, and has been shown to interact with β-catenin and thus limit Wnt signalling. However, various data also indicate a potential role in regulating the cytoskeleton. Ray Dunn and colleagues set out to investigate this further in zebrafish and Xenopus (p. ). In both species, they find that morpholino-induced mcc knockdown leads to phenotypes typical of defects in convergence and extension during gastrulation. Importantly, these phenotypes can be fully rescued by co-injection with Mcc RNA. In zebrafish, the defects in cellular behaviour are very similar to those seen upon disruption of non-canonical Wnt pathway. Through epistasis and biochemical analysis, the authors provide evidence that Mcc is likely involved in transmitting the Wnt signal from Vangl2 to the downstream effectors RhoA and JNK. Although the detailed molecular mechanism remains unclear, these data identify an important role for Mcc as a component of the non-canonical Wnt pathway that coordinates anamniote gastrulation.
