Abnormally large lamellar bodies in type II pneumocytes in Chediak-Higashi syndrome in beige mice.

Lamellar bodies in type II pneumocytes are markedly enlarged in beige mice. The irregular shapes of some of these enlarged specialized lysosomes suggest fusion of smaller ellipsoidal bodies to form the giant organelles, consistent with the proposal of others for the mechanism of formation of abnormal lysosomes in Chediak-Higashi syndrome. Examination of the structure of lamellar bodies by the freeze-fracture technique reveals highly ordered stacking or concentric wrapping of the constituent lamellae. The corrugated patterns evident on the surfaces of normal lamellae are also present in Chediak-Higashi syndrome lamellae. Both normal and Chediak-Higashi syndrome lamellae appear free of typical intramembranous particles. The corrugations seen in the lamellae closely resemble those seen on freeze-fracture of dispersions of lecithin in water.