Desquamating Cells of the Chick Embryo Corneal Epithelium

The chick embryo corneal epithelium undergoes an extensive sloughing of surface cells just prior to hatching (20 days of incubation). The sloughing cells are seen at light and electron microscopic levels to be lighter staining than surrounding cells. They exhibit characteristics of cell death such as nuclear pyknosis, cytoplasmic vacuolization and swelling, and loss of intercellular attachments. The cell coat of the anterior corneal epithelium was examined after treatment of the tissue with alcian blue. Sloughing cells exhibited little or no mucosubstance adhering to their surface while surrounding cells retained a thick coat of mucosubstance.