Experiments in the chaetognathe Spadella performed by June Ordoñez in the Wollesen group also showed that its central nervous system, which forms from two lateral neuroblast clusters, also originates in the BMP-positive domain. We propose that the original function of BMP signaling was pro-neural, and its anti-neural role is just a side effect of the ancestral role of BMP signaling in the global DV patterning seen in animals where a highly centralized CNS happens to develop on the “low BMP side”. Link to paper
