Functional characterization of Lipid storage droplets 1 (LSD1) in growth and lipolysis of Hermetia illucens

As intracellular organelles in adipose tissue, lipids droplets manage the balance between triglyceride accumulation and energy consumption in animals. Perilipin family members, associated with surface of lipid droplets, participate the regulation of lipid metabolism. Lipid storage droplet-1 (LSD1)/Perilipin-1 acts as a gatekeeper for adipose lipid storage in animals. Despite extensive studies in fruit fly, the function of LSD1 in insect larval stage remain indistinct. In this study, we characterized the function of LSD1 in black soldier fly Hermetia illucens, a nova resource insect to recycle organic wastes. We found that LSD1 was broadly present in dipteran species and evolved with divergence between mosquitos and flies. We further constructed in vivo mutagenesis mediated by CRISPR/Cas9 and found that mutations in LSD1 increased the larval weight and did not bring any defects in development. Raw fat content was also not significantly influenced in late larval stage and new-emerged adults. Our results not only extend our knowledge of LSD1 in insects, but also help for better understanding of the lipid homeostasis in BSF.