Involved in specifying the paraxial, but not dorsal, mesoderm. May regulate the expression of T-box transcription factors required for mesoderm formation and differentiation, such as brachyury T, wnt8, vegt and eomes. Expressed specifically in presomitic paraxial mesoderm and its immediate presumptive progenitor cells and sharply down-regulated in presumptive somites. Expression is first detected at gastrulation. Expressed throughout development until the tadpole stage. Expression is predominantly localized in ventrolateral mesoderm but is absent from dorsal mesoderm in gastrulae. In tailbud stage embryos, expression is still detected and is localized to the most caudal (unsegmented) paraxial mesoderm. At the tadpole stage, expression remains in the tailbud.