Adaptation to dietary conditions by trehalose metabolism in Drosophila

Abstract

Trehalose is a non-reducing disaccharide that serves as the main sugar component of haemolymph in insects. Trehalose hydrolysis enzyme, called trehalase, is highly conserved from bacteria to humans. However, our understanding of the physiological role of trehalase remains incomplete. Here, we analyze the phenotypes of several Trehalase (Treh) loss-of-function alleles in a comparative manner in Drosophila. The previously reported mutant phenotype of Treh affecting neuroepithelial stem cell maintenance and differentiation in the optic lobe is caused by second-site alleles in addition to Treh. We further report that the survival rate of Treh null mutants is significantly influenced by dietary conditions. Treh mutant larvae are lethal not only on a low-sugar diet but also under low-protein diet conditions. A reduction in adaptation ability under poor food conditions in Treh mutants is mainly caused by the overaccumulation of trehalose rather than the loss of Treh, because the additional loss of Tps1 mitigates the lethal effect of Treh mutants. These results demonstrate that proper trehalose metabolism plays a critical role in adaptation under various environmental conditions.

iTRAQ‐based quantitative proteome revealed metabolic changes of Sitophilus zeamais in response to terpinen‐4‐ol fumigation

“…Moreover, trehalose is the main insect hemolymph sugar in some insects, and is important in maintaining a number of physiological processes such as providing energy for flight muscles and protecting insects against low temperatures . The loss of trehalase was lethal to fruit flies at the pupal stage, and the decrease of trehalase could affect the supply of energy in S. zeamais .…”

Role of glycogen in development and adult fitness in Drosophila

“…To elucidate the cause of larval lethality, we then investigated whether glycogen mutants exhibit sensitivity to malnutrition. We previously reported that Tps1 mutants are sensitive to sugar deprivation and poor dietary conditions (Matsuda et al, 2015;Yasugi et al, 2017). However, larval lethality in GlyS and GlyP mutants was not changed under a yeast-only (Y-only) diet that largely lacks carbohydrates compared with that of mutants on a normal diet (ND) (Fig.…”

“…Drosophila were reared on fly food (normal diet, ND) containing 8 g agar, 100 g glucose, 45 g dry yeast, 40 g corn flour, 4 ml propionic acid and 0.45 g butylparaben (in ethanol) per liter (1× recipe). For the analysis of restricted or enriched dietary conditions, fly food was prepared as described previously (Matsuda et al, 2015;Yasugi et al, 2017). In brief, fly food containing a reduced or increased amount of yeast or glucose was used (0.2× or 2× the amount used for the 1× recipe).…”

“…All the experiments were conducted under non-crowded conditions at 25°C. The food intake assay was carried out as described previously (Yasugi et al, 2017).…”

“…1A), which also plays an important role in maintaining glucose homeostasis (Elbein et al, 2003; Chng et al, 2017;Mattila and Hietakangas, 2017). In contrast to GlyS and GlyP mutants, null alleles of the trehalose synthesis enzyme Tps1 show complete lethality during metamorphosis, but not during the larval period when dietary sugar is available (Matsuda et al, 2015;Yasugi et al, 2017). To test phenotypic interaction between glycogen and trehalose metabolism, we analyzed the lethality in larvae lacking both glycogen and trehalose metabolism.…”