Figure 1. Dietary E. coli influences fat storage in C. elegans.

(A) Ancestral relationship between four E. coli strains used in this study. OP50 and DA837 are derived from E. coli strain B, HB101 is a B x K12 hybrid, and HT115(DE3) is derived from E. coli K-12. (B) Fat stores in C. elegans depend on the dietary E. coli strain. Young adults were fixed with paraformaldehyde and stained with Nile Red. (C) Lipids were extracted from young adult C. elegans grown on four E. coli strains. Total protein was determined using an aliquot of the nematode pellet used for lipid extraction. Lipid extracts were separated into phospholipids and TAGs using thin layer chromatography and quantified using gas chromatography. Error bars are SEM, n = 3−5 independent growths. The fatty acids in phospholipid fractions did not vary but the relative amount of fatty acids found in TAG fractions varied up to 2 fold depending on the dietary E. coli strain.