Lipid Dynamics, Identification, and Expression Patterns of Fatty Acid Synthase Genes in an Endoparasitoid, Meteorus pulchricornis (Hymenoptera: Braconidae)

In insect parasitoids, fatty acid synthases (FASs) have received less attention and their roles associated with lipogenesis loss are far from clear. is a solitary endoparasitoid wasp of many larvae of lepidopteran pests. The lipid content during developmental stages of was measured; it was higher in the larval and pupal stages but declined from six-day-old pupae. Lipid accumulation constantly decreased in the adult stage, even after feeding on honey solutions. To investigate the roles of FASs in lipid synthesis in , four FAS genes ( ) were identified from the transcriptome database of . All FAS genes included full-length open reading frames and shared 72-79% similarity with the sequences of . qRT-PCR validation showed that all four had the highest expression after the adult wasps were fed on honey diets. and reached their expression peaks at the adult stage but and peaked at the larval stage. To further study the function of FASs, dsRNA injection knocked down the expression of four and resulted in a significant decline of lipid content at the adult stage in . Results from this study suggest that adults cannot accumulate lipid content effectively and FASs may still contribute to lipid synthesis in the adult stage. This broadens the knowledge on the ability of lipid synthesis in parasitoid wasps and provides insight into the roles of FASs in insects with parasitic life-history traits.