Primary cilia of the corneal endothelium

Abstract

A primary cilium is a normal component of every rabbit corneal endothelial cell, rather than being a rare or sporadic organelle, as previously believed. In common with other cilia of this type it possesses an axonemal organization of 9 +0 which converts distally to 8 + 1; it occurs only one per cell; and the basal body is accompanied by a proximal centriole. Additional structures associated with the basal body are nine transitional fibers, four striated satellite arms, and several rootlets. Ladderlike structures extend between the two centrioles to form the wall of a barrel. Reexamination of primary cilia from other tissues indicates that the ultrastructure of endothelial cilia may be characteristic of primary cilia in general.

Scanning electron microscopy of the corneal endothelium of ostrich

“…In the current investigation, we did not detect cilia in the corneal endothelium. However, this structure, protruding into the anterior chamber, was occasionally found in the endothelial cells of humans as well as in other animals (GALLAGHER, 1980). The small pits observed scattered over the cell surface probably represent pinocytotic vesicles, previously documented (SVEDBERGH & BILL, 1972).…”

NDP kinase moves into developing primary cilia

“…Biochemical approaches based on isolated 9+2 cilia and flagella have been useful in the identification of ciliary components, their localization inside the cilium and the interactions governing their import into these organelles. However, there are no published methods for isolation of primary cilia, most probably because in most cells they are minuscule and thus comprise a minute fraction of total cell volume [Gallagher, 1980]. The feasibility of a successful isolation is higher in A6 cells, which have a high incidence of long primary cilia when cultured for an extended period post-confluence (Figs.…”

“…2 and 4). Based on the observation that shear forces can easily lead to deciliation of specimens [Gallagher, 1980], we developed a procedure for isolating primary cilia from A6 cells using brief mechanical agitation in saline followed by differential centrifugation. To prevent damage to the cilia, we avoided detergents and chemicals such as dibucaine, as well as extremes of pH and high calcium.…”

“…Gallagher, 1980] noted their widespread presence and conserved ultrastructure, suggesting that these organelles might have an important function in cells. Some hypothesized that primary cilia might have a sensory role (see Poole et al, 1985 and references thereof), but proof of this function was missing.…”

Association of Nucleoside Diphosphate Kinase with Microtubule-Based Structures

“…Gallagher, 1980) noted their widespread presence and conserved ultrastructure, suggesting that these organelles may have an important function in cells.…”