Morphology of Mitochondria in Syncytial Annelid Female Germ-Line Cyst Visualized by Serial Block-Face SEM

Figure 3

(a–c) Accumulations of mitochondria (Mi) together with the tubules of the endoplasmic reticulum (ER) that enclosed the Golgi complexes (GC) are visible in the nurse cell pole opposite the ring canal, near the cell nucleus (Nu). Note the two distinguishable kinds of mitochondria with electron-dense and electron-lucent matrix, both of them possessing numerous cristae. Granulo-fibrillar nuage material (arrows) was observed close to mitochondrial aggregation within both nurse cells and cytophore (inset). (d) Thioflavin T staining showed that the nuage material was rich in amyloid-like proteins (arrows). NC – nurse cells; Nu – nurse cell nucleus. (e–i) Autophagosomes in nurse cells containing the remnants of cell organelles including the mitochondria (arrows). Tubules of endoplasmic reticulum – ER; Golgi complexes – GC. (a–c), (e–i) Transmission electron microscopy, Epon ultrathin sections; (a) bar = 1.4 µm; (b), (c), (e) bar = 0.9 µm; (f) bar = 0.5 µm; (g, h) bar = 0.4 µm; (i) bar = 0.3 µm. (d) Steedman wax sections stained with thioflavin-T; bar = 45 µm.