(A) Simplified carbohydrate and lipid metabolic pathways. Changes in the expression of genes involved in carbohydrate and fatty acid metabolism are shown. Fold changes at 15 °C and by mdt-15(tm2182) [mdt-15(-)] mutations are shown in circles and squares, respectively. See S3 Table for fold changes and p-values as well as S1 Data and GEO database (accession number GSE128815) for RNA-seq data. (B) mRNA levels of fat-1 through fat-7 in wild-type and mdt-15(-) at 25 °C and 15 °C were measured by using qRT-PCR (two-tailed Student t tests, *p < 0.05, **p < 0.01, ***p < 0.001, n ≥ 3). (C) Quantification of fat-7::GFP fluorescence intensity in wild-type and mdt-15(-) animals at 25 °C and 15 °C (two-tailed Student t tests, **p < 0.01, ***p < 0.001, n ≥ 20 from three independent experiments). Representative images are shown in S3H Fig. See S7 Table for the standard deviations of box plot data. acaa, acetyl-CoA acyltransferase; ACC, acetyl-CoA carboxylase; ACDH, acyl-CoA dehydrogenase; ACO, acyl-CoA oxidase; ACS, acyl-CoA synthetase; aldo, aldolase; atgl, adipose triglyceride lipase; CPT, carnitine palmitoyl transferase; CS, citrate synthase; ECH, enoyl-CoA hydratase; elo, fatty acid elongase; enol, enolase; FAR, fatty-acid–and retinol-binding protein; FAS, fatty acid synthase; FAT, fatty acid desaturase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; GEO, Gene Expression Omnibus; GFP, green fluorescent protein; GPI, glucose-6-phosphate isomerase; HACD, hydroxyacyl-CoA dehydrogenase; hosl, hormone-sensitive lipase; hxk, hexokinase; IDH, isocitrate dehydrogenase; ipgm, cofactor-independent phosphoglycerate mutase; kat, 3-ketoacyl-coA thiolase; LBP, lipid-binding protein; lipl, lipase-like; MDH, malate dehydrogenase; MDT-15, Mediator 15; qRT-PCR, quantitative reverse-transcription PCR; PFK, phospho-fructo-kinase; PGK, phosphoglycerate kinase; PGM, phosphoglycerate mutase; PK, pyruvate kinase; RNA-seq, RNA sequencing; SCS, succinyl-CoA synthetase; SDH, succinate dehydrogenase; TPI, triosephosphate isomerase; α-KGDH, α-ketoglutarate dehydrogenase.