Fig. 3
From: Lethal (2) giant discs (Lgd)/CC2D1 is required for the full activity of the ESCRT machinery
The size of ESCRT-containing electron-dense microdomains is enlarged in lgd mutant MEs. Representative TEM pictures of MVBs of wild-type (A, A’) and lgdd7 mutant (B, B’) wing disc cells. (A’, B’) Defined and measured ESCRT-containing electron-dense microdomains of the MVBs shown in A and B are highlighted in red. Magnification of ESCRT-containing electron-dense microdomains where the associated, nascent ILV is clearly observable (arrowhead). The overall morphology of the MVBs in lgdd7 mutants appears to be normal (B, B’). (C) Statistical analysis of the ESCRT-containing electron-dense microdomains of wild-type and lgdd7 mutant MVBs in wing imaginal disc cells. The average size of lgd mutant electron-dense microdomains is significantly increased in comparison to the wild-type [wt n = 72 MVBs (90 ESCRT-containing electron-dense microdomains); lgdd7 n = 87 MVBs (111 ESCRT-containing electron-dense microdomains); Mann-Whitney test, two-tailed p < 0.0001 (****); scatter dot plot, mean shown as a “line”]. (D–H) Analysis of MEs of cells that are depleted of Rab7 function. (D, D’) A wing disc depleted of Rab7 function in the posterior compartment by the continuous expression of rab7-RNAi with hhGal4 (arrow). The magnification in (D’) highlights the efficiency of the depletion in the posterior compartment (arrow). (E, E’) Representative MEs/MVBs of anterior wild-type and posterior depleted cells. Analysis of the size (F), luminal content (G) and size (H) of the ESCRT-containing electron-dense microdomains of the wild-type and Rab7-depleted MEs/MVBs. While the average size and the luminal content is increased, there is no change in the size of the ESCRT-containing electron-dense microdomains in comparison to wild-type [(F, G) wt (ant.) n = 253 MVBs; (F) rab7-RNAi (post.) n = 282 MVBs; (G) rab7-RNAi (post.) n = 280 MVBs; (F, G) Mann-Whitney test, two-tailed p < 0.0001 (****); box plots: whiskers: 5–95 percentile; mean shown as “+”. (F) Values greater than 1 μm2 are not shown (rab7-RNAi (post.): 8 out of 282 MVBs). (H) wt (ant.) n = 86 MVBs (114 ESCRT-containing electron-dense microdomains); rab7-RNAi (post.) n = 92 MVBs (110 ESCRT-containing electron-dense microdomains) Mann-Whitney test, two-tailed; scatter dot plot; mean shown as a “line”]. Scale bars (A–B’, E, E’) 250 nm; (D) 200 μm; (D’) 50 μm. (D, D’) At least ten wing imaginal discs were analysed for each genotype