Cytoskeleton and tissue origin in the anterior cynomolgus monkey eye.

We studied cytoskeletal proteins and other markers for embryologic origin in the outflow pathways of the aqueous humor, cornea, sclera, and ciliary muscle of the cynomolgus monkey. The corneal endothelium and trabecular cells stained with markers for vimentin, smooth muscle cell alpha-actin, F-actin, spectrin, vinculin, and talin. The endothelium of Schlemm's canal stained with markers for vimentin, spectrin, and F-actin. These results suggest that trabecular cells are a kind of myofibroblast and support the belief that the endothelial cells of Schlemm's canal are vascular in origin. Fibrillary staining with antibodies to vimentin, spectrin, neurofilament protein, and glial acid fibrillary protein was observed along and between the ciliary muscle cells. Cells in the deep sclera adjacent to the supraciliary space stained with antibodies to smooth muscle alpha-actin, alpha-vinculin, talin, and desmin. These cells may anchor ciliary muscle cells into the sclera or may be developmental remnants of ciliary muscle cells. Leu 19 immunoreactivity was found in the corneal endothelium, in all trabecular cells, in ciliary muscle cells, and in keratocytes and fibroblasts in the superficial part of the cornea and sclera. All of these cells are therefore likely to express neural cell adhesion molecules indicating neuroectodermal origin.