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Evidence that conserved developmental gene-regulatory networks can change as a unit during deutersostome evolution emerges from a study published in BMC Biology. This shows that genes consistently expressed in anterior brain patterning in hemichordates and chordates are expressed in a similar spatial pattern in another deuterostome, an asteroid echinoderm (sea star), but in a completely different developmental context (the animal-vegetal axis). This observation has implications for hypotheses on the type of development present in the deuterostome common ancestor. © 2011 McDougall and Degnan; licensee BioMed Central Ltd.
McDougall, C., & Degnan, B. M. (2011). Modularity of gene-regulatory networks revealed in sea-star development. BMC Biology, 9. https://doi.org/10.1186/1741-7007-9-6