Fig. 5. Cyclopropane-containing glycolipids are enriched in hacl-1 mutants.

a Leucine metabolism feeds into branched-chain fatty acid (BCFA) biosynthesis in C. elegans. b Pairwise analysis of Leu or ¹³C₆-Leu-supplemented worms using the Label Finder revealed ¹³C₅-enriched NAEs derived from BCFAs. Shown are representative HPLC-MS (ESI+) EICs and dotted lines represent incorporation of ¹³C₅ (Δm/z, 5.0167), as visualized using Metaboseek Mass Shifts. c Study design for comparative metabolomics of WT and hacl-1 worms fed either E. coli OP50 or cyclopropane fatty acid-deficient E. coli JW1653-1. d Representative HPLC-MS (ESI-) EIC for 496.2317, corresponding to cyclopropane-containing N-acyl GPE 13:1 (17). Shown structure was proposed based on MS/MS fragmentation and absence in JW1653-1. e Quantification of N-acyl GPEs that were absent from worms fed JW1653-1. Data represent six (WT) or five (hacl-1) samples from three biologically independent experiments and bars means ± SD. f Representative HPLC-MS (ESI-) EIC for m/z 570.2674, corresponding to cyclopropane-containing GLEA 13:1 (18). Shown structure was proposed based on MS/MS fragmentation and absence in JW1653-1. Asterisks (*) mark isobaric hacl-1-enriched features that are not impacted by JW1653-1 diet. g Proposed metabolism of bacterial 17:1 (or 19:1) cyclopropane lipids. Three (or four) rounds of β-oxidation would produce an 11:1 cyclopropane fatty acid unsuitable for further β-oxidation that could be a substrate for α- or ω-oxidation. Source data are provided as a Source Data file.