Format

Send to

Choose Destination
Development. 2016 Nov 15;143(22):4167-4172. Epub 2016 Oct 5.

Antagonism between β-catenin and Gata.a sequentially segregates the germ layers of ascidian embryos.

Author information

1
Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
2
Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
3
Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, Villefranche-sur-mer 06230, France.
4
Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, Villefranche-sur-mer 06230, France yasuo@obs-vlfr.fr yutaka@ascidian.zool.kyoto-u.ac.jp.
5
Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan yasuo@obs-vlfr.fr yutaka@ascidian.zool.kyoto-u.ac.jp.

Abstract

Many animal embryos use nuclear β-catenin (nβ-catenin) during the segregation of endomesoderm (or endoderm) from ectoderm. This mechanism is thus likely to be evolutionarily ancient. In the ascidian embryo, nβ-catenin reiteratively drives binary fate decisions between ectoderm and endomesoderm at the 16-cell stage, and then between endoderm and margin (mesoderm and caudal neural) at the 32-cell stage. At the 16-cell stage, nβ-catenin activates endomesoderm genes in the vegetal hemisphere. At the same time, nβ-catenin suppresses the DNA-binding activity of a maternal transcription factor, Gata.a, through a physical interaction, and Gata.a thereby activates its target genes only in the ectodermal lineage. In the present study, we found that this antagonism between nβ-catenin and Gata.a also operates during the binary fate switch at the 32-cell stage. Namely, in marginal cells where nβ-catenin is absent, Gata.a directly activates its target, Zic-r.b (ZicL), to specify the marginal cell lineages. Thus, the antagonistic action between nβ-catenin and Gata.a is involved in two consecutive stages of germ layer segregation in ascidian embryos.

KEYWORDS:

Ascidian; Ciona intestinalis; Gata; Germ layer formation; Zic; β-Catenin

PMID:
27707797
DOI:
10.1242/dev.141481
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center