A Global In Vivo Drosophila RNAi Screen Identifies a Key Role of Ceramide Phosphoethanolamine for Glial Ensheathment of Axons
(A) Addition of sphingosine to diet rescues the lace phenotype. Arrowheads indicate glial swelling region. (B) Orthogonal projections showed that dietary addition of sphingosine rescues the enwrapment defect. (C) Quantification of average cross-section area after knockdown of lace in glia and upon sphingosine treatment is shown. All graphs represent mean values ± SD. One-way ANOVA followed by Tukey post hoc test was performed for statistical analysis. Scale 20 µm (D1–D3) TEM micrographs of L3 larval peripheral nerve cross-sections are shown. Wrapping glia is color-coded. Vacuoles (blue arrowhead) are present in the wrapping glia and there is loss of membrane extension resulting in lack of proper ensheathement in repo-GAL4/lace RNAi flies as compared to control repo-GAL4/+ flies. (D3) Addition of 300 µM sphingosine to the diet (Matreya, USA) rescues the ensheathment defect. (E) Quantification of the number of unwrapped axons before and after sphingosine treatment in the in lace knocked down flies. (repo-GAL4/laceRNAi). One-way ANOVA followed by Tukey post hoc test was performed. All graphs represent mean values ±SD. *** p<0.001.