On the role of fibronectin during the compaction stage of somitogenesis in the chick embryo.

During the early stages of somitogenesis in the chick embryo the presomitic cells in the segmental plate undergo compaction. The aggregation of segmental plate cells is stimulated by fibronectin. The stimulation of segmental plate cells to aggregate and undergo compaction can be effected in isolated segmental plate cells, in isolated segmental plates, and in intact embryos removed from the yolk. The fact that the segmental plate cells react with greater vigor to cellular fibronectin than to plasma fibronectin suggests a specific molecular mechanism in the initiation of somitogenesis.