Mitochondrial pleiomorphism in sustentacular cells of Xenopus laevis.
The mitochondrial population of sustentacular cells in the testis of the amphibian, Xenopus laevis, has been examined by electron microscopy. Three distinct types of mitochondria have been observed. The first and most common mitochondrial type is a "typical" organelle with a rod-like profile containing tubular to plate-like cristae. The second mitochondrial form is characterized externally by irregular bulbous protrusions and internally by increased numbers of tubular cristae. The third mitochondrial type, which is usually ovoid in profile, has the most unusual internal membrane configuration, consisting of pleated folds pierced by regular rows of fenestrations. Mitochondrial type one is found in all sustentacular stages, mitochondrial type two first appears in sustentacular cells surrounding early spermatids, and mitochondrial type three is observed only in sustentacular cells surrounding spermatozoa. These observations indicate that discrete subclasses of mitochondria are present in sustentacular cells of Xenopus.
D000818:Animals; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure*; D012708:Sertoli Cells / Q000648:ultrastructure; D013094:Spermatozoa / Q000648:ultrastructure; D013737:Testis / Q000648:ultrastructure*; D014981:Xenopus