Nuclear accumulation of β-catenin and transcription of downstream genes are regulated by zygotic Wnt5α and maternal Dsh in ascidian embryos

Narudo Kawai, Yohei Iida, Gaku Kumano, Hiroki Nishida

Research output: Contribution to journalArticle

24 Citations (Scopus)


Nuclear β-catenin plays crucial roles in the establishment of the embryonic axis and formation of mesendoderm tissues in ascidians and other animals. However, the cue responsible for nuclear accumulation of β-catenin in the vegetal hemisphere is still unknown in ascidians. Here, we investigated the roles of Wnt5α and Dsh in the nuclear accumulation of β-catenin and activation of its downstream genes in the ascidian Halocynthia roretzi. Wnt5α knockdown embryos lost nuclear accumulation of β-catenin at the 64-cell stage but not at the 32-cell stage, and expression of Hr-lim, one of the targets of β-catenin, was impaired in the anterior region of the embryo. Zygotic Wnt5α expression in the anterior-vegetal blastomeres was primarily responsible for these defects. Dsh knockdown showed no effect on nuclear localization of β-catenin, but inhibited Hr-lim expression in the posterior region. These results suggest that maintenance of nuclear Hr-β-catenin after the 64-cell stage is regulated by zygotic Hr-Wnt5α, and that expression of its target genes is modulated by both Hr-Wnt5α and Hr-Dsh. Our results also highlight the importance of nuclear accumulation of β-catenin up to the 32-cell stage through a still unclarified mechanism.

Original languageEnglish
Pages (from-to)1570-1582
Number of pages13
JournalDevelopmental Dynamics
Issue number6
Publication statusPublished - 2007 Jun 1



  • Ascidian embryo
  • Dsh
  • Lim
  • Nuclear transport
  • Wnt5α
  • β-catenin

ASJC Scopus subject areas

  • Developmental Biology

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