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XB-ART-54803
Dev Dyn January 1, 2018; 247 (7): 903-913.

Tbx2 is required for the suppression of mesendoderm during early Xenopus development.

Teegala S , Chauhan R , Lei E , Weinstein DC .


Abstract
BACKGROUND: T-box family proteins are DNA-binding transcriptional regulators that play crucial roles during germ layer formation in the early vertebrate embryo. Well-characterized members of this family, including the transcriptional activators Brachyury and VegT, are essential for the proper formation of mesoderm and endoderm, respectively. To date, T-box proteins have not been shown to play a role in the promotion of the third primary germ layer, ectoderm. RESULTS: Here, we report that the T-box factor Tbx2 is both sufficient and necessary for ectodermal differentiation in the frog Xenopus laevis. Tbx2 is expressed zygotically in the presumptive ectoderm, during blastula and gastrula stages. Ectopic expression of Tbx2 represses mesoderm and endoderm, while loss of Tbx2 leads to inappropriate expression of mesoderm- and endoderm-specific genes in the region fated to give rise to ectoderm. Misexpression of Tbx2 also promotes neural tissue in animal cap explants, suggesting that Tbx2 plays a role in both the establishment of ectodermal fate and its dorsoventral patterning. CONCLUSIONS: Our studies demonstrate that Tbx2 functions as a transcriptional repressor during germ layer formation, and suggest that this activity is mediated in part through repression of target genes that are stimulated, in the mesendoderm, by transactivating T-box proteins. Taken together, our results point to a critical role for Tbx2 in limiting the potency of blastula-stage progenitor cells during vertebrate germ layer differentiation. Developmental Dynamics 247:903-913, 2018. © 2018 Wiley Periodicals, Inc.

PubMed ID: 29633424
PMC ID: PMC6105467
Article link: Dev Dyn
Grant support: [+]
Genes referenced: bix1.3 bmp4 chrd.1 dand5 dll1 eomes flrt3 foxi1 gdf3 gsc krt12.4 mab21l3 nodal sox17b.1 sox2 sox3 szl tbx2 tbx4 tbx5 tbxt vegt ventx2.1 ventx2.2 wnt11 wnt11b wnt8a
GO keywords: dorsal/ventral neural tube patterning [+]
Morpholinos: foxi1 MO3 foxi1 MO6 tbx2 MO5


Article Images: [+] show captions
References:
Abrahams, 2010, Pubmed [+]


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