Functions as a transcriptional activator playing a crucial role during development. Functions in gastrulation, regulating mesoderm differentiation. Activates wnt8, t/bra, chrd and mix-A/mix.1 expression. First expressed at or just after midblastula transition (stage 8). Maximally expressed at stage 10 as an equitorial mesoderm band, more prominently on the dorsal side and around the invaginating dorsal lip. By activin and derriere.