Persistent ER Stress Induces the Spliced Leader RNA Silencing Pathway (SLS), Leading to Programmed Cell Death in Trypanosoma brucei
Figure 10
TEM of SLS-induced cells demonstrating morphological changes characteristic of apoptosis.
A. Electron micrographs of untreated cells (i-iv), SEC63 cells after 48 hours of silencing (v-x), and cells treated with 4 mM DTT for 5 hours (xi-xiv) or 12 hours (xv-xvii); (xiii-xiv) sections were immunostained with anti BiP antibodies. N, nucleus; Nuc, nucleolus; M, mitochondria; ER, endoplasmic reticulum; AP, autophagosomes; fp, flagellar pocket. Scale bars: 1 µm. In each panel, the relevant structure is indicated with an arrow (as described in the text). B. Autophagosome formation under SEC63 silencing or DTT treatment. Cells carrying the silencing construct of SEC63 as well as the tagged YFP-ATG8 construct or parental cells carrying YFP-ATG8 constructs were visualized by live imaging using fluorescence microscopy. Parental cells were either i. uninduced (-Tet) or induced for 48 hrs (+Tet); ii. Untreated cells (control) or cells treated with DTT for 4 hrs (DTT), DIC- differential interference contrast. Scale bars, 5 µm.