The epicuticular lipid barrier is highly dynamic across the life course in Drosophila
Authors: Lena Lampe 1; Clare L Newell 1; Ian Gilmore 2; Alex P Gould 1
Affiliations: 1) Francis Crick Institute; 2) National Physical Laboratory
Keywords: j. physiology of adult organs; q. other (Mass Spectrometry)
An epicutaneous lipid barrier is found in all terrestrial organisms and protects them from dehydration and other potentially harmful stresses in the environment. The high surface area to volume ratio of insects means that an effective epicuticular lipid barrier to dessication is particularly important. The composition of the barrier lipid blend is highly complex and, although hydrocarbons have been extensively analysed, other cuticular lipid species are less well investigated. Here we use a new surface-specific technique for mass spectrometry, OrbiSIMS, to characterize the cuticular lipid repertoire of Drosophilamelanogaster during ageing. We identify epicuticular ceramides, wax esters, phospholipids and free fatty acids and show that they have specific temporal profiles that change substantially during ageing. Using stable isotope tracing, we measure the turnover rates of epicuticular lipids and show that larval nutritional resources contribute greatly to some but not all molecular species. This study shows how larval nutrition contributes to the adult epicuticular lipid blend and the quality of the dessication barrier.