(A) Body length measurement of fath-1 RNAi worms rescued by BSA control, 350 μM (R)-2-OH FA (2R) or 350 μM (S)-2-OH FA (2S) supplementation. N ≥ 50 for each data set. (B) Body length measurements showing the rescuing effects of 5, 20, 35, 50, 100 or 200 μM alkynyl 2-OH-PA supplementation on the growth arrest defect caused by fath-1 RNAi. N ≥ 50 for each data set. (C) Distribution of fatty acids and derivatives in the C. elegans intestine labeled by “Click chemistry” approach. PA, palmitic acid; OH-PA, 2-hydroxy plamitic acid; alk, alkynyl; az, azide. Scale bar, 5 μm.