Key maternal determinant of the dorsal organizer and body axis formation in vertebrates that acts by promoting stabilization of beta-catenin (ctnnb1) (PubMed:30467143). Localizes on the plasma membrane of the future dorsal blastomeres in early blastulas and binds to and promotes the tankyrase-mediated degradation of axin (axin1 and axin2) (PubMed:30467143). Axin degradation results in stabilization and nuclear translocation of beta-catenin (ctnnb1) for activating organizer-specific target gene expression (PubMed:30467143). Interacts with axin1; leading to promote the tankyrase-mediated degradation of axin (PubMed:30467143). Interacts with axin2; leading to promote the tankyrase-mediated degradation of axin (PubMed:30467143). Enriched on the plasma membrane of blastomeres only in a small region in which the dorsal organizer will form. Expressed maternally (PubMed:30467143). Transcripts are first distributed evenly in blastomeres (PubMed:30467143). During the early cleavage period, transcripts in the vegetal pole region are transported toward the animal pole from one side of the yolk (PubMed:30467143). Transcript levels decrease 2 hours post fertilization (PubMed:30467143). The protein is enriched in a small region of blastomeres, in which the dorsal organizer will form (at protein level) (PubMed:30467143). Maternal mutant embryos lack the body axis: embryos develop normally during cleavage and blastula stages but lack the embryonic shield at the shield stage (PubMed:30467143). The dorsal organizer is absent and embryos fail to form the head and other dorsoanterior tissues (PubMed:30467143). Was named huluwa after the Chinese animation TV series huluwa, known as Calabash Brothers in western countries. Belongs to the huluwa family.