Table 1.
Mass spectrometry detection of 2-monoacylglycerols and 6 classes of N-acyl amides in Oregon-RS larvae.
Table 2.
Mass spectrometry detection of 6 classes of N-acyl amides in Oregon-RS larvae.
Figure 1.
Identification of 2-linoleoyl glycerol (2-LG) from third instar Oregon-RS larvae.
(A) Matching chromatographic peaks of synthetic 2-LG standard and LIII Drosophila lipid extracts. (B) Product ion scan for the parent ion 355.5 [H+] using the 2-LG standard. (C) Product ion scan for the parent ion 355.5 [H+] using the lipid extract from Oregon-RS Drosophila larvae.
Figure 2.
Overlay chromatograms from mass spectrometric data comparing synthetic standards and lipid extracts from third instar Oregon-RS larvae.
This is an example of the type of data that are compared via the analytical software to determine chromatographic/mass spectrometric matches from unknown samples to the synthetic standards. Here, the example of the HPLC/MS/MS chromatogram generated using the analytical method for the synthetic standard of N-linoleoyl ethanolamine is overlaid with a partially purified lipid extract from third instar Oregon-RS larvae. Matching retention times and chromatographic peaks that are generated with the mass spectrometric match of the MS/MS of the parent/fragment ion pair associated with the synthetic standards provide clear evidence that the same compound exists in the extract sample.
Figure 3.
Representative overlay chromatograms of eight N-linoleoyl amides isolated from third instar Oregon-RS larvae.
Lipid extracts analyzed using HPLC/MS/MS were from Oregon-RS Drosophila larvae raised on base diet formulation. A–H) Chromatographic overlays of two individual scans show identical retention times for the standards (in black) and analytes isolated from Drosophila lipid extracts (grey). Insets show the molecular structure of each lipid. (3B is a replica of the example given in Fig. 2. It is shown here to provide a standard for how it relates to the other analogous compounds.).
Figure 4.
Representative overlay chromatograms of four N-linoleoyl amides isolated from third instar Oregon-RS larvae
. Lipid extracts analyzed using HPLC/MS/MS were from Oregon-RS Drosophila larvae raised on base diet formulation. I–L) Chromatographic overlays of two individual scans show identical retention times for the standards (in black) and analytes isolated from Drosophila lipid extracts (grey). Insets show the molecular structure of each lipid.
Figure 5.
Comparative lipidomics in Oregon-RS, Canton-S and w1118 strains.
(A) Third instar larvae (LIII) were reared simultaneously and photographed to demonstrate the lack of gross bodily differences. (B) T1117, a lipophilic dye without known receptors in Drosophila melanogaster [28], was used to localize the accumulation of dietary lipids. The Cha-Gal4 driver in combination with the UAS-GFP reporter was used to reveal both the central and peripheral cholinergic system in LIII. Note that the fat body is the primary site of lipophilic dye accumulation. (C–E) Comparative lipidomics in the three wild-type strains revealed comparable 2-LG and N-linoleoyl glycine, but not N-linoleoyl ethanolamine (p = 0.0017 Oregon-RS vs. w1118; (E) contents. Scale bars = 1 mm.