A Gene causing Ocular Retardation in the Mouse

The development of the eyes in mice homozygous for the gene ocular retardation (or) is described here. Up to the age of 11 days the eyes of or/or embryos appear to be normal in their size and general proportions, but after this time they are reduced in size. This is due to the failure of the central artery and vein to establish a pathway along the choroid fissure, which closes completely. In the adult the lens is never crystalline and is always distorted in shape, while the retina contains no sensory cells, no optic nerves develop, and there is no optic chiasma. An orbit of normal size is filled with hypertrophied Harderian and lachrymal glands.