Somites are transient embryologic structures that differentiate into precursors for skeletal muscles as well as bone and cartilage of the axial skeleton. Embryological and genetic analyses have identified the molecular signals that initiate somite pattern formation. Among these signals are members of the BMP family, as well as BMP antagonists that restrict their activity in specific cells of the developing embryo.

In this and a previous study, we investigated the role of BMP antagonists Noggin, Follistatin and Gremlin in patterning the axial skeleton. We present evidence that Follistatin, Noggin and Gremlin1 participate in a ‘‘BMP antagonist relay’’ in early sclerotome development, consistent with a persistent function for BMP/BMP antagonist signaling during the differentiation of somite derivatives.