Figure 6

Morphogenesis of the iris and ciliary zone. Diagram showing location of insets for the developing (A) and mature (H) iris and ciliary zone. Histology of the 3 dpf developing dorsal (B) and ventral (E) iris. TEM micrographs from 3 dpf show pigment cell stratification in dorsal (C) and ventral (F) regions. Note the reduced differentiation as indicated by pigmentation within the ventral region. Corresponding drawings indicate the principle cell types found within the developing iris (D, G). Color shadings indicate cells of similar embryonic origins. Histology of the 1 month old zebrafish dorsal (I) and ventral (L) iris. TEM micrographs show differences in the ultrastructure of non-pigmented ciliary epithelial cells between dorsal (J) and ventral (M) regions. Insets show the membranous infolding and secretory appearance within the dorsal ciliary zone (K) and the lack of this morphology in the ventral non-pigmented ciliary epithelium (N). RBC, red blood cell; UN, undifferentiated cell; Xa, xanthophore; Me, melanocyte; Ir, iridophore; CE, corneal epithelium; CN, corneal endothelium; NR, neural retina.