Fig. 1

Mutation of kun54 leads to excessive lipid accumulation. a–c rrp-8(kun54) is a mutant strain obtained from a forward genetic screen of fat regulators by EMS mutagenesis. Compared with wild-type (WT) worms, rrp-8(kun54) worms consistently show increased lipid accumulation by a Nile Red staining, b LipidTox Red staining, and c Oil Red staining of fixed worms. The stained particles are lipid droplets (LDs) in representative 1-day-old adult worms. Scale bar represents 20 μm. Magnification, × 400. d Distribution of the lipid droplet size (% lipid droplets), as measured from Nile Red staining of fixed worms from a. Data are presented as mean ± SD of 10 animals for each worm strain. e Lipid contents were quantified by TLC/GC and presented as the percentage of triacylglycerol (% TAG) in total lipids (TAG + phospholipids, PL). Data are presented as the mean ± SD of four biological repeats. f Genetic mapping of the kun54 mutation (the mapping details are shown in Supplementary Fig. 1) and the mutated position of kun54 in T07A9.8 is indicated by an asterisk. g Information for generation of the rrp-8(kun122) mutation. Top panel: schematic diagram of the generation of the kun122 mutation (42 bp deletion) using CRISPR/cas-9 technology. The red arrow indicates the site of the designed sgRNA. Bottom panel: Nile Red staining of fixed worms. h Distribution of the lipid droplet size (% lipid droplets), as measured in Nile Red-stained fixed worms from g. Data are presented as the mean ± SD of 10 animals for each worm strain. i Nuclear localization of RRP-8::GFP with DAPI (upper panel, fluorescence microscopy) and the nucleolar marker mCherry::FIB-1 (lower panel, confocal microscopy). Scale bar represents 10 μm in upper panel and 20 μm in lower panel. j Fluorescence microscopy of nuclear expression of RRP-8::GFP {kunEx121[Prrp-8::rrp-8::gfp]} throughout different developmental stages (embryo to L4 larvae). In all of the represented animals, the anterior is indicated on the left and posterior is indicated on the right. Significant difference between WT and a specific worm strain, Student’s t-test, ***P < 0.001