Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Echinobase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Echinobase
ECB-ART-42982
Dev Biol 2013 Oct 01;3821:268-79. doi: 10.1016/j.ydbio.2013.07.027.
Show Gene links Show Anatomy links

New regulatory circuit controlling spatial and temporal gene expression in the sea urchin embryo oral ectoderm GRN.

Li E , Materna SC , Davidson EH .


Abstract
The sea urchin oral ectoderm gene regulatory network (GRN) model has increased in complexity as additional genes are added to it, revealing its multiple spatial regulatory state domains. The formation of the oral ectoderm begins with an oral-aboral redox gradient, which is interpreted by the cis-regulatory system of the nodal gene to cause its expression on the oral side of the embryo. Nodal signaling drives cohorts of regulatory genes within the oral ectoderm and its derived subdomains. Activation of these genes occurs sequentially, spanning the entire blastula stage. During this process the stomodeal subdomain emerges inside of the oral ectoderm, and bilateral subdomains defining the lateral portions of the future ciliary band emerge adjacent to the central oral ectoderm. Here we examine two regulatory genes encoding repressors, sip1 and ets4, which selectively prevent transcription of oral ectoderm genes until their expression is cleared from the oral ectoderm as an indirect consequence of Nodal signaling. We show that the timing of transcriptional de-repression of sip1 and ets4 targets which occurs upon their clearance explains the dynamics of oral ectoderm gene expression. In addition two other repressors, the direct Nodal target not, and the feed forward Nodal target goosecoid, repress expression of regulatory genes in the central animal oral ectoderm thereby confining their expression to the lateral domains of the animal ectoderm. These results have permitted construction of an enhanced animal ectoderm GRN model highlighting the repressive interactions providing precise temporal and spatial control of regulatory gene expression.

PubMed ID: 23933172
PMC ID: PMC3783610
Article link: Dev Biol
Grant support: [+]

Genes referenced: gemin2 LOC100887844 LOC575170 nodall spdef
Morpholinos: gscl MO2 spdef MO2 zeb2 MO3

References [+] :
Ben-Tabou de-Leon, Gene regulatory control in the sea urchin aboral ectoderm: spatial initiation, signaling inputs, and cell fate lockdown. 2013, Pubmed, Echinobase