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Evolutionary rewiring of gene regulatory network linkages at divergence of the echinoid subclasses
Citation: Erkenbrack, E. M., & Davidson, E. H. (2015). Evolutionary rewiring of gene regulatory network linkages at divergence of the echinoid subclasses.Proceedings of the National Academy of Sciences, 112(30), E4075-E4084.
Significance: This work provides direct evidence of evolutionary rewiring of gene-regulatory circuitry accompanying divergence of two subclasses of echinoderm, the cidaroid and euechinoid sea urchins. These forms descend from a known common Paleo- zoic ancestor, and their embryos develop differently, offering an opportunity to probe the basic evolutionary process by which clade divergence occurs at the gene-regulatory net- work (GRN) level. We carried out a systematic analysis of the use of particular genes participating in embryonic skeleto- genic cell specification, building on an established euechinoid developmental GRN. This study revealed that the well-known and elegantly configured regulatory circuitry that underlies skeletogenic specification in modern sea urchins is largely a novel evolutionary invention. The results dramatically dis- play extensive regulatory changes in a specific developmental GRN, underlying an incidence of cladistic divergence at the subclass level.

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Notch-mediated lateral inhibition is an evolutionarily conserved mechanism patterning the ectoderm of echinoids

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©  2016 Eric M Erkenbrack and PNAS. All rights reserved.