Figure 5
Schematic representation of the proposed hypothesis on the modulation of males’ metabolism after feeding on raspberry fruit medium. Nutrient deficiency, specifically carbohydrate deficiency, activates the production of Adipokinetic hormone (Akh) in the Corpora Cardiaca (CC) which will bind to the Akh receptor (AkhR), promoting the dephosphorylation of the Forkhead box O (FOXO) transcription factor and mobilization to the nucleus. This will promote TAG and glycogen mobilization for glucose production by gluconeogenesis, and trehalose production by trehaloneogenesis mediated by Trehalose-6-phosphate synthase 1 (Tps1). Due to low sugar content in raspberry, there is a need to increase glucose and trehalose levels, therefore the expression of Trehalase (Treh) and sorbitol dehydrogenase (Sodh) remain unchanged. Simultaneously, there is a feedback activation of the insulin receptor (InR) by FOXO, in order to maintain the receptor more prone to binding of the Drosophila insulin-like peptides (Dilps) produced by the insulin-producing cells (IPC) after the detection of higher levels of glucose.
