Analysis of Drosophila Lipids by Matrix-Assisted Laser Desorption/ Ionization Mass Spectrometric Imaging

Drosophila melanogaster is a major model organism for numerous lipid-related diseases. While comprehensive lipidomic profiles have been generated for D. melanogaster, little information is available on the localization of individual lipid classes and species. Here, we show the use of matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) to profile lipids in D. melanogaster tissue sections. The preparation of intact cryosections from whole insects presents a challenge due to the brittle hydrophobic cuticle surrounding the body and heterogeneous tissue types beneath the cuticle. However, the introduction of a novel sucrose infiltration step and gelatin as an embedding media greatly improved the quality of tissue sections. We generated MS image profiles of six major lipid classes: phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, and triacylglycerides. In addition, signals corresponding to two male-specific sex pheromon...