Transcription factor that binds to the octamer motif (5'-ATTTGCAT-3'). Antagonizes the activity of nodal/activin signaling during gastrulation to suppress mesendoderm formation. Acts maternally to inhibit vegt and beta-catenin-activated gene transcription, probably by forming a transcriptional repression complex on the promoters of target genes. Binds to an octamer motif in interspersed RNA. Interacts with the transcription factors tcf7l1/tcf3 and vegt. Expressed in the animal half of oocytes and remains localized to the animal cap and marginal zone of blastula embryos. Expressed in the adult ovary and at a very low level in the adult kidney. Absent from primordial germ cells (PGCs). Expressed maternally. Most abundant in oocytes and fertilized eggs, with expression maintained through the cleavage stages of development until early gastrulation. Expression levels drop abruptly during gastrulation (stage 11) but remain at very low levels through larval stages. Belongs to the POU transcription factor family. Class-5 subfamily.