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-43739
Elife 2014 Dec 02;3:e04664. doi: 10.7554/eLife.04664.
Show Gene links Show Anatomy links

Early asymmetric cues triggering the dorsal/ventral gene regulatory network of the sea urchin embryo.

Cavalieri V , Spinelli G .


Abstract
Dorsal/ventral (DV) patterning of the sea urchin embryo relies on a ventrally-localized organizer expressing Nodal, a pivotal regulator of the DV gene regulatory network. However, the inceptive mechanisms imposing the symmetry-breaking are incompletely understood. In Paracentrotus lividus, the Hbox12 homeodomain-containing repressor is expressed by prospective dorsal cells, spatially facing and preceding the onset of nodal transcription. We report that Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent transcription. Reciprocally, impairing hbox12 function disrupts DV polarity by allowing ectopic expression of nodal. Clonal loss-of-function, inflicted by blastomere transplantation or gene-transfer assays, highlights that DV polarization requires Hbox12 action in dorsal cells. Remarkably, the localized knock-down of nodal restores DV polarity of embryos lacking hbox12 function. Finally, we show that hbox12 is a dorsal-specific negative modulator of the p38-MAPK activity, which is required for nodal expression. Altogether, our results suggest that Hbox12 function is essential for proper positioning of the DV organizer.

PubMed ID: 25457050
PMC ID: PMC4273433
Article link: Elife


Species referenced: Echinodermata
Genes referenced: gscl LOC100887844 LOC105439014 LOC115919910 nodall otp otx2 pmar1 pou2f1


Article Images: [+] show captions
References [+] :
Agca, Respecification of ectoderm and altered Nodal expression in sea urchin embryos after cobalt and nickel treatment. 2009, Pubmed, Echinobase