[Crystallization of reptile hemoglobin during its digestion in a pentastomide]

The hemoglobin of the lizard Tarentola annularis has been studied within erythrocytes being digested in the gut of a parasitic pentastomide, Raillietiella sp. The hemoglobin is crystallized in the form of bundles comprised of numerous tubules (up to 2000). These tubules are simple or complex. Simple tubules are 50 nm in diameter; their wall is made up of two electron-opaque rings, separated by a clear ring. Complex tubules are up to 100 nm in diameter and show as many as 13 concentric walls. High magnification of transverse sections of simple tubules show 96 granules; each opaque ring is made up of 48 granules. Human hemoglobin is known to crystallize as 18-nm tubules, the wall of which is made up of six molecules; comparison of these data with our observations indicates that transverse sections of tubules of crystallized lizard hemoglobin should contain 24 molecules. Thus, each molecule of crystallized lizard hemoglobin consists of four granules; these granules may be considered as globin molecules. Erythrocytes in fresh lizard blood do not show crystallized hemoglobin; however, in blood treated with sodium bisulfite, they show tubules similar to that found in the parasite.