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Echinobase
ECB-ART-42669
Dev Biol 2013 Feb 01;3741:245-54. doi: 10.1016/j.ydbio.2012.11.013.
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Gene regulatory control in the sea urchin aboral ectoderm: spatial initiation, signaling inputs, and cell fate lockdown.

Ben-Tabou de-Leon S , Su YH , Lin KT , Li E , Davidson EH .


Abstract
The regulation of oral-aboral ectoderm specification in the sea urchin embryo has been extensively studied in recent years. The oral-aboral polarity is initially imposed downstream of a redox gradient induced by asymmetric maternal distribution of mitochondria. Two TGF-β signaling pathways, Nodal and BMP, are then respectively utilized in the generation of oral and aboral regulatory states. However, a causal understanding of the regulation of aboral ectoderm specification has been lacking. In this work control of aboral ectoderm regulatory state specification was revealed by combining detailed regulatory gene expression studies, perturbation and cis-regulatory analyses. Our analysis illuminates a dynamic system where different factors dominate at different developmental times. We found that the initial activation of aboral genes depends directly on the redox sensitive transcription factor, hypoxia inducible factor 1α (HIF-1α). Two BMP ligands, BMP2/4 and BMP5/8, then significantly enhance aboral regulatory gene transcription. Ultimately, encoded feedback wiring lockdown the aboral ectoderm regulatory state. Our study elucidates the different regulatory mechanisms that sequentially dominate the spatial localization of aboral regulatory states.

PubMed ID: 23211652
PMC ID: PMC3548969
Article link: Dev Biol
Grant support: [+]

Genes referenced: bmp2 LOC100887844 LOC115919910 LOC764641 nodall
Morpholinos: LOC577801 MO2 bmp2 MO1 dlxl MO1 dvr1 MO1 hmxl1 MO1 hoxal MO2 irx4 MO2 msx1 MO2 tbx2 MO1

References [+] :
Armstrong, Cell-cell interactions regulate skeleton formation in the sea urchin embryo. 1993, Pubmed, Echinobase