Further Observations on the Fine Structure of Acanthamoeba palestinensis (Reich, 1933). The Golgi Complex, Microbodies, and Mitochondria

The fine structure of the trophozoite of Acanthamoeba palestinensis with a special emphasis on the Golgi complex, microbodies, and mitochondria has been examined. Golgi complexes are distributed throughout the cytoplasm but are most abundant in the perinuclear region. Usually two Goigi complexes are found in the same plane on opposite sides of the nucleus. One of them appears to be in an intimate association with the nuclear membrane. The region of contact contains compact cisternae, vesicles of various sizes, as well as granular and amorphous electron‐dense material. Structural changes in the nuclear envelope are also observed in this area. A structure consisting of a Golgi complex and electron‐dense microtubule organizing center, comparable to the centrosphere of other Acanthamoeba species, has been observed. Microbodies, surrounded by a single unit membrane and containing a granular matrix and tubular inclusions, are scattered throughout the cytoplasm. These organelles, circular (∼1 μm in diameter) or ovoidal (∼1 μm in length and ∼0.5 μm in width) in section, have often an irregular outline. These microbodies are probably the morphological equivalent of peroxisomes and glyoxysomes. Most mitochondria show a typical structure including tubular cristae and intracristal inclusions. Occasionally mitochondria with two apposed double membranes running through the midline are found. Such atypical cristae have never been reported in small amoebae before.