Table 1.
Percentage [%] of cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in N. heteropoda that showed signs of autophagy.
Table 2.
Percentage [%] of apoptotic cells in the anterior region of the intestine and proximal zone of hepatopancreatic epithelium in N. heteropoda.
Table 3.
Percentage [%] of necrotic cells in the entire intestine and proximal zone of the hepatopancreatic epithelium in N. heteropoda.
Fig 1.
Autophagosomes formation in the N. heteropoda midgut.
(A) Cells of the proximal zone of the hepatopancreatic tubules. TEM. Bar = 0.55 μm. (B-C) Intestine digestive cells that showed signs of autophagy. TEM. (B) Bar = 0.4 μm. (C) Bar = 0.5 μm. (D) Hepatopancreatic epithelial cell that showed signs of autophagy. TEM. Bar = 0.45 μm. Cisterns of the endoplasmic reticulum (ER), mitochondria (m), vesicles with electron-dense content (v), autophagosomes (au), agglomerations of degenerating organelles (asterisks), phagophore formation (arrows).
Fig 2.
Autophagy in the N. heteropoda midgut.
(A) Hepatopancreas. TEM. Bar = 0.15 μm. (B-D) Intestine digestive cells. (B) TEM. Bar = 0.1 μm. (C) Mitophagy. TEM. Bar = 0.15 μm. (D) Mitophagy. TEM. Bar = 0.55 μm. (E-F) Hepatopancreas. (E) TEM. Bar = 0.75 μm. (F) TEM. Bar = 0.45 μm. Autophagosomes (au), autolysosomes (al), residual body (rb), cisterns of the endoplasmic reticulum (ER), mitochondria (m), microvilli (mv), midgut lumen (l), vacuoles (v), lamellar bodies (lb), lipids (l).
Fig 3.
Autolysosomes and acid phosphatase localization in the N. heteropoda midgut.
(A) Transverse section through the intestine with pink spots of acid phosphatase localization. Midgut lumen (l), midgut epithelium (e). Acid phosphatase staining. Light microscope. Bar = 20 μm. (B) Transverse section through the hepatopancreatic tubule with pink spots of acid phosphatase localization. Midgut lumen (l). Acid phosphatase staining. Light microscope. Bar = 30 μm. (C) Transverse section through the intestine. Negative control for acid phosphatase staining. Midgut lumen (l) midgut epithelium (e). Light microscope. Bar = 19 μm. (D) Intestine. Electron-dense autolysosomes (al), mitochondria (m), cisterns of ER (ER), microvilli (mv). Acid phosphatase staining. TEM. Bar = 0.8 μm. (E) Hepatopancreas. Electron-dense autolysosomes (al), cisterns of ER (ER). Acid phosphatase staining. TEM. Bar = 0.8 μm. (F) 3D representation of the accumulation of lysosomes and autolysosomes (red signals). Nuclei (blue signals). A fragment of the intestine. LysoTracker Red and Hoechst 33342 staining. Confocal microscope. Bar = 10.5μm. (G) 3D representation of the accumulation of lysosomes and autolysosomes (red signals). Nuclei (blue signals). A fragment of the proximal zone of the hepatopancreas. LysoTracker Red and Hoechst 33342 staining. Confocal microscope. Bar = 10μm.
Fig 4.
Apoptosis in the N. heteropoda midgut.
3D representation of the Tunel assay and Hoechst 33342 staining. Nuclei of apoptotic cells (red), nuclei (blue). Confocal microscope. (A) Fragment of the anterior region of the intestine. Bar = 9.5μm. (B) Fragment of the hepatopancreatic tubule. Bar = 11μm.
Fig 5.
Ultrastructural features of apoptotic cells in the N. heteropoda midgut.
(A-C) Intestine. TEM. (A) Electron-dense cytoplasm of an apoptotic cell (ac). Distinct extracellular spaces (arrows) between the apoptotic and neighboring digestive cells (dc). Bar = 1.7 μm. (B-C) Lobular shaped nucleus (n) with patches of heterochromatin. (B) Bar = 1 μm. (C) Bar = 1.2 μm. (D-E) Hepatopancreas. TEM. (D) Apoptotic cell (ac) losing contact with the basal lamina (bl). Bar = 1.5 μm. (E) Apoptotic cell (ac) discharged into the midgut lumen (l). Bar = 2 μm. Cisterns of ER (ER), vacuoles (v), mitochondria (m), nucleus (n), nucleolus (nu), basal lamina (bl).
Table 4.
Alterations of the cell and organelles during apoptosis and necrosis.
Fig 6.
Necrosis in the N. heteropoda midgut.
(A) Intestine. TEM. Bar = 1 μm. (B) Hepatopancreas. TEM. Bar = 0.9 μm. Necrotic cell (nc) with electron-lucent cytoplasm, midgut lumen (l), digestive cells (dc) of the intestine, mitochondria (m), microvilli (mv), cisterns of ER (ER).
Fig 7.
Mitochondrial potential in the N. heteropoda midgut epithelium.
(A) Transformed mitochondria (mt) that are devoid of cristae and normal mitochondria (m) in the apical cytoplasm of the digestive cells of intestine. Microvilli (mv), midgut lumen (l). TEM. Bar = 0.6 μm. (B) Normal mitochondria (m) in the apical cytoplasm of the digestive cells of intestine. Cisterns of ER (ER), fragment of the nucleus (n). TEM. Bar = 0.4 μm. (C-D) Active mitochondria with a high membrane potential (red signals), inactive mitochondria with a low membrane potential (green signals). JC-1 cationic dye. Confocal microscope. (C) Bar = 10 μm. (D) Bar = 9 μm. (E) A diagrammatic representation of the average percentage of cells with depolarized mitochondria in the intestine (in) (5.1%) and hepatopancreas (hp) (3.9%).
Table 5.
Percentage [%] of intestinal and hepatopancreatic epithelial cells with depolarized mitochondria in N. heteropoda.
Table 6.
The localization of autophagy, apoptosis and necrosis in different regions of the midgut in N. heteropoda.