Ultrastructure of Anaplasma marginale after freeze-fracture.

Stained thin sections and freeze-fractured replicas of Anaplasma marginale-infected bovine erythrocytes were examined by electron microscopy. Freeze-fracture replication not only verified basic Anaplasma ultrastructure, but also allowed visualization of structures not previously reported. Because of the partial 3-dimensional views obtained with freeze-fracture replication, a new structure that appears as a protruding tip was discernible. Also, the surface of Anaplasma's limiting membrane was less granular than the fractured surface of host erythrocyte. A corrugated surface with a periodicity of 10.5 nm was seen when the limiting membrane was fractured.