Dspastin dosage affects LD number and size in skeletal muscle and nerves.

(A) Representative images of Drosophila larvae muscles labeled with acetylated α-tubulin and BODIPY 493/503. Dspastin^K467R expression and loss of Dspastin in muscle cells using the Mef2-Gal4 promoter reduced drastically LDs within the tissue. Muscle specific overexpression of Dspastin (Dspastin/Mef2-Gal4) caused increased LD number and size. Control genotype (Mef2-Gal4/+). Scale bar, 10 μm. Quantification of LD number (B) and size distribution (C) in muscles. Significance was calculated using unpaired t-test (two tailed) in B and Mann-Whitney test in C. Differences were considered statistically significant at p<0.05 (*) and p<0.005 (**). (D) Drosophila larval muscle expressing myc-tagged Dspastin^K467R was labeled with an anti-myc antibody and LDs with BODIPY 493/503. White arrows show LD localization of Dspastin^K467R. Scale bar, 5 μm. (E) Maximum intensity projections of proximal ventral ganglion nerves from Drosophila third instar larvae expressing Dspastin, Dspastin^K467R, DspastinRNAi under the neuronal driver Elav-Gal4 and controls (Elav-Gal4/+). Nerves were labeled with acetylated α-tubulin to visualize stable MTs and BODIPY 493/503 to detect LDs. Nerves overexpressing wild-type Dspastin show increased LD size and number, whereas Dspastin downregulation (DspastinRNAi/Elav-Gal4) and Dspastin^K467R expression (DspastinK467R/Elav-Gal4) resulted in a loss of LDs. Scale bar, 10 μm. Quantification of LD number (F) and size distribution (G) in nerves. Significance was calculated using unpaired t-test (two tailed) in F and Mann-Whitney test in G.