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XB-ART-49423
Dev Biol November 1, 2014; 395 (1): 38-49.

Developmental enhancers are marked independently of zygotic Nodal signals in Xenopus.

Gupta R , Wills A , Ucar D , Baker J .


Abstract
To determine the hierarchy of transcriptional regulation within the in vivo vertebrate embryo, we examined whether developmental enhancers were influenced by Nodal signaling during early embryogenesis in Xenopus tropicalis. We find that developmental enhancers, defined by the active enhancer chromatin marks H3K4me1 and H3K27ac, are established as early as blastula stage and that Smad2/3 only strongly associates with these regions at gastrula stages. Significantly, when we perturb Nodal signaling using the drug SB431542, most enhancers remain marked, including at genes known to be sensitive to Nodal signaling. Overall, as enhancers are in an active conformation prior to Nodal signaling and are established independently of Nodal signaling, we suggest that many developmental enhancers are marked maternally, prior to exposure to extrinsic signals.

PubMed ID: 25205067
PMC ID: PMC4517478
Article link: Dev Biol
Grant support: [+]

Species referenced: Xenopus laevis
Genes referenced: eomes gsc lefty nodal nodal1 otx2 pitx2 smad2 smad3

GEO Series: GSE56000: NCBI

Article Images: [+] show captions
References [+] :
Akkers, A hierarchy of H3K4me3 and H3K27me3 acquisition in spatial gene regulation in Xenopus embryos. 2009, Pubmed, Xenbase