Dietary protein content alters both male and female contributions to Drosophila melanogaster female post-mating response traits. Schultzhaus Janna N,Carney Ginger E Journal of insect physiology Males transfer sperm, proteins and other molecules to females during mating. In Drosophila melanogaster, these molecules contribute to the induction of egg maturation, ovulation, oviposition, sperm storage and changes in female receptivity. This suite of physiological and behavioral changes is referred to as the female post-mating response (PMR). Protein is a necessary macronutrient for both male and female reproduction, but imbalances in protein content can decrease reproductive potential. Dietary protein affects the production of proteins in the male ejaculate that are important for induction of the PMR, and female fecundity increases with dietary protein while lifetime mating rate decreases. The effects of dietary protein levels on other aspects of the female PMR and on male ability to induce the PMR are unknown. To investigate how protein content affects PMR, we raised flies on diets containing low, moderate or high levels of protein and mated females and males from each diet in a combinatorial manner. We first measured the mating duration for each pair, an indication of male reproductive investment, and then evaluated two aspects of the female PMR, fecundity and female remating latency. We found that mating duration was negatively correlated with male dietary protein, and females that mated with high protein males laid fewer eggs. Female diet had no effect on mating duration, but females fed diets with higher protein content laid more eggs and remated sooner. Therefore, dietary protein levels can affect postcopulatory processes important for reproductive output in a sexually dimorphic manner. 10.1016/j.jinsphys.2017.04.004

Time-restricted feeding promotes muscle function through purine cycle and AMPK signaling in Drosophila obesity models. Nature communications Obesity caused by genetic and environmental factors can lead to compromised skeletal muscle function. Time-restricted feeding (TRF) has been shown to prevent muscle function decline from obesogenic challenges; however, its mechanism remains unclear. Here we demonstrate that TRF upregulates genes involved in glycine production (Sardh and CG5955) and utilization (Gnmt), while Dgat2, involved in triglyceride synthesis is downregulated in Drosophila models of diet- and genetic-induced obesity. Muscle-specific knockdown of Gnmt, Sardh, and CG5955 lead to muscle dysfunction, ectopic lipid accumulation, and loss of TRF-mediated benefits, while knockdown of Dgat2 retains muscle function during aging and reduces ectopic lipid accumulation. Further analyses demonstrate that TRF upregulates the purine cycle in a diet-induced obesity model and AMPK signaling-associated pathways in a genetic-induced obesity model. Overall, our data suggest that TRF improves muscle function through modulations of common and distinct pathways under different obesogenic challenges and provides potential targets for obesity treatments. 10.1038/s41467-023-36474-4

DO-SRS imaging of diet regulated metabolic activities in Drosophila during aging processes. Aging cell Lipid metabolism plays crucial roles during aging processes, but how it is regulated by diets and how it interplays with aging still remain unclear. We proposed a new optical imaging platform by integrating heavy water (D O) probing with stimulated Raman scattering (DO-SRS) microscopy, for the first time, to directly visualize and quantify lipid metabolism regulated by different diets and insulin signaling pathway in Drosophila fat body during aging. We found that calorie restriction, low protein diet, and (moderately) high protein and high sucrose diets enhanced lipid turnover in flies at all ages, while (moderately) high fructose and glucose diets only promoted lipid turnover in aged flies. The measured lipid turnover enhancements under diverse diets were due to different mechanisms. High protein diet shortened the lifespan while all other diets extended the lifespan. Downregulating the insulin signaling pathway enhanced lipid turnover, which is likely related to lifespan increase, while upregulating insulin signaling pathway decreased lipid turnover that would shorten the lifespan. Our study offers the first approach to directly visualize spatiotemporal alterations of lipid turnover in aging Drosophila in situ, for a better understanding of the interconnections between lipid metabolism, diets, and aging. 10.1111/acel.13586

A protein restricted diet induces a stable increased fat storage phenotype in flies. Toxicology reports Background:Scientific evidence has revealed possible confounders in diet induced obesity models of . High Sugar Diet (HSD) induction of obesity in flies has been associated with fly hyperosmolarity and glucotoxicity, while High Fat Diet (HFD) induction has been associated with lipotoxicity. The objective of this study was to assess for a healthy obesity phenotype by comparison of fly survival, physio-chemical and biochemical changes associated with HSD, HFD and Protein Restricted Diet (PRD) obesity induction models of male . Here, we provide information on a PRD as the plausible option in obesity research not involving cancer, diabetes, glucotoxicity and lipotoxicity studies. Methods:Obesity was induced by exposing white mutant to four experimental diets for four weeks. Group 1 was fed regular food (control), group 2 was fed a 0.5% less yeast than in regular feed (PRD), group 3 was fed a 30% w/v sucrose to regular cornmeal food (HSD) and group 4 was fed a 10% w/v food-grade coconut oil to regular cornmeal food (HFD). Peristaltic waves were measured on 3rd instar larvae of all experimental groups. Negative geotaxis, fly survival, body mass, catalase activity, triglycerides (TG/TP), sterol, and total protein were measured in adult after four weeks. Results:Triglycerides (TG/TP) and total protein levels were significantly higher in HSD phenotype. Sterols were higher in HFD phenotype. Though catalase enzyme activity was highest in PRD phenotype, this activity was not statistically significant when compared to that of HSD and HFD phenotypes. However, PRD phenotype had the lowest mass, highest survival rate and the highest negative geotaxis, thus demonstrating a balanced, stable and more viable metabolic status in the experimental model. Conclusion:A protein restricted diet induces a stable increased fat storage phenotype in . 10.1016/j.toxrep.2023.06.003

Epidermal tyrosine catabolism is crucial for metabolic homeostasis and survival against high-protein diets in Drosophila. Development (Cambridge, England) The insect epidermis forms the exoskeleton and determines the body size of an organism. How the epidermis acts as a metabolic regulator to adapt to changes in dietary protein availability remains elusive. Here, we show that the Drosophila epidermis regulates tyrosine (Tyr) catabolism in response to dietary protein levels, thereby promoting metabolic homeostasis. The gene expression profile of the Drosophila larval body wall reveals that enzymes involved in the Tyr degradation pathway, including 4-hydroxyphenylpyruvate dioxygenase (Hpd), are upregulated by increased protein intake. Hpd is specifically expressed in the epidermis and is dynamically regulated by the internal Tyr levels. Whereas basal Hpd expression is maintained by insulin/IGF-1 signalling, Hpd induction on high-protein diet requires activation of the AMP-activated protein kinase (AMPK)-forkhead box O subfamily (FoxO) axis. Impairment of the FoxO-mediated Hpd induction in the epidermis leads to aberrant increases in internal Tyr and its metabolites, disrupting larval development on high-protein diets. Taken together, our findings uncover a crucial role of the epidermis as a metabolic regulator in coping with an unfavourable dietary environment. 10.1242/dev.202372