Developmental Changes for the Hemolymph Metabolome of Silkworm (Bombyx mori L.)

Abstract

Silkworm (Bombyx mori) is a lepidopteran-holometabolic model organism. To understand its developmental biochemistry, we characterized the larval hemolymph metabonome from the third instar to prepupa stage using 1H NMR spectroscopy whilst hemolymph fatty acid composition using GC-FID/MS. We unambiguously assigned more than 60 metabolites, among which tyrosine-o-β-glucuronide, mesaconate, homocarnosine, and picolinate were reported for the first time from the silkworm hemolymph. Phosphorylcholine was the most abundant metabolite in all developmental stages with exception for the periods before the third and fourth molting. We also found obvious developmental dependence for the hemolymph metabonome involving multiple pathways including protein biosyntheses, glycolysis, TCA cycle, the metabolisms of choline amino acids, fatty acids, purines, and pyrimidines. Most hemolymph amino acids had two elevations during the feeding period of the fourth instar and prepupa stage. Trehalose was the major blood sugar before day 8 of the fifth instar, whereas glucose became the major blood sugar after spinning. C16:0, C18:0 and its unsaturated forms were dominant fatty acids in hemolymph. The developmental changes of hemolymph metabonome were associated with dietary nutrient intakes, biosyntheses of cell membrane, pigments, proteins, and energy metabolism. These findings offered essential biochemistry information in terms of the dynamic metabolic changes during silkworm development.

Metabolomics differences between silkworms (Bombyx mori) reared on fresh mulberry (Morus) leaves or artificial diets

“…All nutrients and water silkworms need come from mulberry leaves, which is a result of the long-term co-evolution and natural selection between silkworms and mulberry trees 7 , 8 . Nutrients in mulberry leaves that can be used by silkworms are mainly proteins, carbohydrates, lipids, inorganic matter, moisture, and vitamins 9 – 13 . Although artificial diets for silkworms have mimicked the composition of mulberry leaves, rearing silkworms on artificial diets comprising a large amount of mulberry leaf powder has achieved comparable results to rearing them on mulberry leaves.…”

Silkworm (Bombyx mori) has the Capability to Accumulate C20 and C22 Polyunsaturated Fatty Acids

“…Overall, the unsaturated FAs (USFAs) content reached the highest level in the wandering stage and then gradually decreased to a level consistent with that in the larval stage. It was reported that FAs in insects participated the biosynthesis of proline, which act a key role as the primary energy substrate in flight muscle metabolism . The decrease of USFAs may be due to the expenditure of energy in the stage of pupa and moth, and the biosynthesis of proline may be more specifically from PUFAs.…”

Comparative proteomics analysis of silkworm hemolymph during the stages of metamorphosis via liquid chromatography and mass spectrometry

“…Of 50 proteins involved in the metabolism pathway, eight were involved in glycolysis/gluconeogenesis, seven in arginine and proline metabolism, five in fructose and mannose metabolism, and five in the citrate cycle (TCA cycle). In comparison, a recent metabolome study identified multiple pathways in the silkworm hemolymph including protein biosynthesis, glycolysis, the TCA cycle, and purine and pyrimidine metabolism . It is likely that numerous enzymes and related proteins might play key roles in the glycolysis, amino acid metabolism, the biosynthesis and degradation of proteins, and energy metabolism during silkworm development and metamorphosis.…”