Glycerophospholipid Profiles of Allomyrina dichotoma Larvae at Different Instars Based on Lipidomics and Transcriptomics Suggest a Promising Lipid Source

The farming of insects has emerged as a novel source of proteins and lipids. The larvae of <i>Allomyrina dichotoma</i>, an important source insect, contain large concentrations of lipids; however, the constituents of these lipids are unknown. We used lipidomics and transcriptomics to analyze the deposition of glycerophospholipids in <i>A. dichotoma</i> larvae at different instars. A total of eight subclasses of 833 glycerophospholipid molecules were identified in <i>A. dichotoma</i> larvae. The results showed the lipid with the highest levels in <i>A. dichotoma</i> larvae was phosphatidylethanolamine (PE) followed by phosphatidylcholine (PC), and phosphatidylglycerol (PG). Glycerophospholipids in <i>A. dichotoma</i> larvae at three instars were clearly differentiated. Large amounts of PE and PC were deposited in Stage 3 larvae, and cardiolipin (CL), phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidic acids (PAs) showed a similar pattern. However, PG and phosphatidylinositol diphosphate (PIP) decreased in Stage 3 larvae. Furthermore, the metabolic pathways and the key genes related to glycerophospholipid synthesis were identified based on transcriptomes for <i>A. dichotoma</i> larvae. These results revealed the composition of glycerophospholipids. We also explored the molecular mechanism for deposition of glycerophospholipids during the developmental stages of <i>A. dichotoma</i> larvae. Our results provide insights for using <i>A. dichotoma</i> larvae to produce lipids.