Mitochondria attached to desmosomes in the ciliary epithelia of human, monkey, and rabbit eyes

In the normal ciliary epithelia of the rhesus monkey, owl monkey, albino rabbit, and human eye, a previously unreported relationship exists between mitochondria and certain desmosomes. At these sites, two mitochondria appear like "sentinels" attached to the cytoplasmic surfaces of their respective sides of a desmosome. In other instances, only one side of the junction may be afforded an associated mitochondrion. In each case the cytoplasmic filaments of the desmosome are seen to blend with the outer membrane of the mitochondrion. The relationship between desmosomes and mitochondria in the ciliary epithelium is unique among ocular tissues. A survey of ocular epithelia in the various species examined, failed to give any evidence of similar junctional/organelle complexes. Various functional roles for this relationship are discussed including the possibility that the mitochondria could control the cytoplasmic calcium ion concentration in the microenvironment of their associated desmosomal junctions.