Cooperation and regulatory loops of multiple nodals are essential for mesendoderm patterning in early embryos. Essential for mesoderm formation and axial patterning during embryonic development. Activates the activin-like signaling pathway to induce dorsal and ventral mesoderm in animal cap ectoderm. In addition, also dorsalizes ventral marginal zone (VMZ) tissues during gastrulation. Induces muscle actin. Appears to act as both a short-range and long-range morphogen. The unprocessed protein inhibits bmp- and wnt-signaling. Homodimer; disulfide-linked (By similarity). Forms heterodimers with the TGF-beta family member derriere (PubMed:12070085). Interacts with tsku; enhances nodal2 activity (PubMed:17925852). First localized to the vegetal region of the blastula. Just prior to gastrulation (stage 10), this expression disappears and instead becomes localized to the dorsal marginal zone, with enrichment in the organizer. First expressed at late blastula (stage 9) with expression peaking at early gastrula. Expression then disappears and does not return. By dorsal mesoderm-inducing signals including activin and other nodal-related proteins. The pro-region is necessary but not sufficient for wnt-inhibitory activity. The central region is required for muscle induction activity. Belongs to the TGF-beta family.