High fat diet induced abnormalities in metabolism, growth, behavior, and circadian clock in Drosophila melanogaster.

AIMS: The current lifestyle trend has made people vulnerable to diabetes and related diseases. Years of scientific research have not been able to yield a cure to the disease. The current study aims to investigate a link between high-fat diet mediated diabesity and circadian rhythm in the Drosophila model and inferences that might help in establishing a cure to the dreaded disease.

MAIN METHODS: Several experimental methods including phenotypical, histological, biochemical, molecular, and behavioral assays were used in the study to detect obesity, diabetes, and changes in the circadian clock in the fly model.

KEY FINDINGS: The larva and adults of D.melanogaster exposed to high-fat diet (HFD) displayed excess deposition of fat as lipid droplets and micronuclei formation in the gut, fat body, and crop. Larva and adults of HFD showed behavioral defects. The higher amount of triglyceride, glucose, trehalose in the whole body of larva and adult fly confirmed obesity-induced hyperglycemia. The overexpression of insulin gene (Dilp2) and tribble (trbl) gene expression confirmed insulin resistance in HFD adults. We also observed elevated ROS level, developmental delay, altered metal level, growth defects, locomotory rhythms, sleep fragmentation, and expression of circadian genes (per, tim, and clock) in HFD larva and adults. Thus, HFD impairs the metabolism to produce obesity, insulin resistance, disruption of clock, and circadian clock related co-mordities in Drosophila melanogaster.

SIGNIFICANCE: The circadian gene expression provides an innovative perspective to understand and find a new treatment for type-II diabetes and circadian anomalies.