Simple Summary
An optimal internal response to feeding state is critical for survival and development in insects. Part of this response originates in the insect midgut, which detects the nutritional status of incoming food and sends relevant signals to other organs via hormones. Starvation leads to changes in insect behaviors, such as food-seeking, and physiology, such as modifying nutrient usage to save energy for survival. Therefore, in this study, proteomics was used on fed and starved tobacco hornworm (Manduca sexta) caterpillar digestive tracts to characterize how the midgut responds to starvation. Several processes were modified by starvation, including digestive enzymes and metabolic functions. Additionally, gut-produced neuropeptide hormones were detected, and some changed in abundance in starved insects, particularly neuropeptide F1, which suggests that the dynamics of neuropeptide F1 are tied to feeding state. Overall, this study provides a foundation for understanding the gut response, particularly the dynamics of neuropeptide hormones, to starvation and provides multiple targets for future work.
Starvation is a complex physiological state that induces changes in protein expression to ensure survival. The insect midgut is sensitive to changes in dietary content as it is at the forefront of communicating information about incoming nutrients to the body via hormones. Therefore, a DIA proteomics approach was used to examine starvation physiology and, specifically, the role of midgut neuropeptide hormones in a representative lepidopteran, Manduca sexta. Proteomes were generated from midguts of M. sexta fourth-instar caterpillars, starved for 24 h and 48 h, and compared to fed controls. A total of 3047 proteins were identified, and 854 of these were significantly different in abundance. KEGG analysis revealed that metabolism pathways were less abundant in starved caterpillars, but oxidative phosphorylation proteins were more abundant. In addition, six neuropeptides or related signaling cascade proteins were detected. Particularly, neuropeptide F1 (NPF1) was significantly higher in abundance in starved larvae. A change in juvenile hormone-degrading enzymes was also detected during starvation. Overall, our results provide an exploration of the midgut response to starvation in M. sexta and validate DIA proteomics as a useful tool for quantifying insect midgut neuropeptide hormones.
Kaur, G.; Quilici, D.R.; Woolsey, R.J.; Petereit, J.; Nuss, A.B.
2024,
Starvation induced changes to the midgut proteome and neuropeptides in Manduca sexta,
Insects 2024, 15(5), 325
