Fig. 4. Ciliary band neurons.
BioTapestry model of neurogenesis of postoral and ciliary band neurons. Specification occurs following the early patterning of the ventral ectoderm. First the postoral neurons begin to be specified. soxC expression is activated by Soxb1. Delta is activated shortly thereafter to signal through Notch to neighboring cells resulting in repression of neurogenesis in the Notch-activated cells, thereby restricting the number of neurons specified. When the ciliary band appears, ciliary band neurons complete their specification and differentiate. Solid lines represent perturbations reported in the literature. The connections may or may not be direct since cis-regulatory confirmation has not been conducted. Dashed lines represent likely connections that are only preliminarily established. Diamond input into Nodal represents an early asymmetry of uncertain origin.