Fig. 1: sisR-1 regulates mitochondrial clumping during fasting.
From: Nutrient-dependent regulation of a stable intron modulates germline mitochondrial quality control
A Germline cells at different stages of oogenesis. G: germarium, S: stage. B Number of stage 14 oocytes per ovary in fed and fasted y w, sisR-1 RNAi line 1 and 2. Data are presented as mean values +/−SD. *p < 0.001. n = 30 ovaries. Two-tailed t-test. C Relative levels of sisR-1 normalized against actin5C in y w fed versus fasted oocytes. Data are presented as mean values +/−SD from three biological replicates. *p = 0.01. Two-tailed t-test. D Relative levels of sisR-1 normalized against actin5C in control sibling versus nos-Gal4 > TOR RNAi ovaries. Data are presented as mean values +/−SD from n = 3 biological replicates. *p < 0.01. Two-tailed t-test. E Confocal images of stage 8/9 egg chambers showing localization of sisR-1 (Green), ATP5α (Red) and DAPI (Blue) in Oregon R fed with yeast paste for 2 days and fasted for 1 day post eclosure. Boxed region is magnified. Arrowheads point to mitochondrial clumps that colocalize with sisR-1 in fasted females. Scale bar = 20 µm. F Percentages of cytoplasmic sisR-1 dots that colocalize with mitochondrial clumps. Data are presented as mean values +/−SD. ***p < 0.001. n = 5 (fed), 8 (fasted) slices. Two-tailed t-test. G Mitochondria isolation showing enrichment of sisR-1 in mitochondrial fractions. ATP5α and β-Tubulin were used as positive controls. N = 2 biological replicates. H Confocal images of stage 8/9 egg chambers showing ATP5α localization in fasted Oregon R, sisR-1 RNAi line 1 and 2. Arrowheads point to mitochondrial clumps in fasted Oregon R. Scale bar = 20 µm. I Percentages of total stage 8/9 egg chambers with mitochondrial clumps in Oregon R and sisR-1 RNAi line 1 and 2 (n = 100 egg chambers) *p < 0.001. Chi-square test, one-sided.  J Number of clumps per egg chamber present in stage 8/9 egg chamber that contain clumps. Data are presented as mean values +/−SD. *p < 0.01. n = 9 (Oregon R), 7 (RNAi #1), 9 (RNAi #2) egg chambers. Two-tailed t-test. K Proposed model on how fasting affects sisR-1 levels and causes mitochondrial clumping. Source data are provided as a Source Data file.
