Insulin-Like Peptides Regulate Feeding Preference and Metabolism in

Area of Science:

• * Entomology
• * Molecular Biology
• * Metabolic Regulation

Background:

• * Drosophila insulin-like peptides (DILPs) regulate hemolymph carbohydrates and storage metabolites.
• * DILPs are crucial for maintaining metabolic homeostasis in insects.

Purpose of the Study:

• * Investigate diet-dependent roles of DILPs (dilp1-5, dilp7) in fruit fly appetite and metabolism.
• * Analyze effects of DILP gene mutations on nutrient intake, storage, and hemolymph carbohydrate levels.
• * Understand the evolutionary pathways of metabolic regulation.

Main Methods:

• * Utilized wild type and mutant fruit fly lines (dilp1-7).
• * Employed response surface methodology to evaluate metabolic differences across various diets.
• * Monitored insect appetite, food choice (carbohydrates vs. proteins), and accumulation of triglycerides, glycogen, glucose, and trehalose.

Main Results:

• * Compensatory feeding for carbohydrates observed in wild type and mutants.
• * Mutants (dilp2,3, dilp3, dilp5, dilp7) showed increased protein consumption on high-yeast diets.
• * Specific dilp mutations (dilp2, dilp3, dilp5, dilp7) significantly altered glycogen, trehalose, and triglyceride levels, with dilp3 and dilp7 impacting appetite.

Conclusions:

• * DILPs play critical, diet-specific roles in regulating fruit fly appetite and metabolism.
• * Drosophila serves as a valuable model for studying metabolic diseases and metabolic regulatory evolution.
• * Specific DILP mutations lead to distinct metabolic phenotypes, highlighting their individual contributions.