Nutritional Value Formation of Silkworm Pupa at Different Growth Stages: Analysis from Multi-omics Perspective

Silkworm pupa (Bombyx mori) is affinal drug and diet in China, which is rich in protein and human essential amino acids. However, it is unclear how the internal nutritional composition changes and the antioxidant situation throughout the transformation of a silkworm pupa into a silkworm moth. In this study, we investigated the samples from four growth stages during silkworm pupal emergence by integrating proteomics and metabolomics. The results of the systematic bioinformatics study revealed that the growth of silkworm pupae considerably altered the ribosome-related genetic expression, cuticle development, and folate metabolism. The partial redox-active amino acid levels and the level of peroxiredoxin 1 expression were consistent with the fact that the total antioxidant capacity was higher in 7- and 10-day-old silkworm pupae. As compared to silkworm pupae, the amounts of fatty acids rose while those of amino acids, peptides, and organic acids dropped. This research also discovered that the altered protein profiles of silkworm pupae were controlled by the differential expression of mTOR signaling proteins (V-ATPase, S6, eIF4E) and ubiquitin mediate proteins (RP-L40e, UBE2L3, UBE2N, SKP1, ELOC). This study provided a new scientific foundation for the development and utilization of edible insect silkworm pupa functional food products.