Transcription factor required for both mesoderm and endoderm formation in the embryo; signaling determinants and concentration levels may determine which germ layer is formed. Acts together with beta-catenin to activate genes that are responsible for mesoderm induction including wnt-8, eomes t/bra, siamois, mix1 and sox17. Directly binds to promoter DNA. Patterns the mesoderm along the dorsoventral and posterior axis. Activates siamois gene transcription when alone or in combination with beta-catenin, but inhibits siamois transcription in combination with pou5f1.1/oct-25. Forms a repression complex on the promoters of the nodal/nr1 and siamois genes with the maternal factors tcf7l1/tcf3 and pouf5.1/oct-25. Interacts (via C-terminus) with tcf7l1/tcf3 (via N-terminus). Also interacts with the other POU-domain transcription factors pou5f1.2/oct-91 and pou5f1.3/oct-60. Uniformly distributed in stage I oocytes but becomes localized to the vegetal hemisphere by stage II and remains so thereafter throughout oogenesis and the early embryonic cleavage stages. Zygotic expression parallels blastopore formation and shifts from dorsal expression in the marginal zone of late blastula and early gastrula stages to a ventral/lateral expression at the posterior end of later stage embryos. Expression is excluded from the notochord. In tailbud and tadpole stages, expressed exclusively in a subset of posterior Rohon-Beard neurons. Expressed both maternally and zygotically. Maternally expressed from early oogenesis. Zygotic expression occurs from late blastula and reaches maximum levels during gastrulation (stages 10.5-12). Levels decline at the time of blastopore closure (stage 13). By mesoderm inducing factors and TGF-beta family members including nodal/nr-1 acting in an autoregulatory loop, nodal2/nr-2 derriere, bFGF and activin B. Was named Antipodean by PubMed:9012537 because of its localization to the vegetal hemisphere of the egg.