File:Sea Urchin-endomesoderm induction.png

Gene Regulatory Networks Underlying Endomesoderm Induction

(A) The micromere determinant Pmar1 (circled in red) activates the PMC-GRN in micromere progeny and is sufficient for micromere-derived endomesoderm-inducing signals. The E-EM/En-GRNs (up to 17 h postfertilization) integrate the regulatory functions of maternal and zygotic core factors that drive the earliest steps of endomesoderm progenitor specification in sea urchin embryos. The zygotically expressed core factors Z13, Eve, Wnt8, Blimp1, FoxA, and Brachyury (Bra) (circled in black) accumulate in presumptive endomesoderm during early developmental stages and could potentially respond to early inductive inputs from micromere descendants.

(B) Schematic depicting an experiment that reveals micromere-derived endomesoderm inductive signals, which are sufficient to induce ectopic endo16 expression and complete archenteron formation in animal blastomeres, and are also necessary for normal vegetal endo16 expression and timely gastrulation in the sea urchin embryo. The regulatory interactions among these signals and the overall EM-GRN are unknown. GRN diagram is adapted from [8].

doi:10.1371/journal.pbio.1000029.g001

Original file name: Journal.pbio.1000029.g001.png

http://www.plosbiology.org/article/info:doi%2F10.1371%2Fjournal.pbio.1000029

Citation: Sethi AJ, Angerer RC, Angerer LM (2009) Gene Regulatory Network Interactions in Sea Urchin Endomesoderm Induction. PLoS Biol 7(2): e1000029. doi:10.1371/journal.pbio.1000029

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