A heteroallelic Drosophila insulin-like receptor mutant and its use in validating physiological activities of food constituents.

Here we report an additional Drosophila transheterozygote InR(GS15311)/InR(GS50346) carrying two different P-element-inducible alleles of insulin-like receptor gene (InR). InR(GS15311)/InR(GS50346) flies exhibit the following phenotypes previously reported in InR and insulin/IGF-1 signaling (IIS) pathway-related gene mutants: small bodies, developmental delay, shortened lifespan, and increased fasting resistance. All of these characteristics are shared among flies carrying mutated genes implicated in the pathway. This heteroallelic combination exhibited fertility but resulted in male semilethality, while females were viable and grew into adults. Furthermore, an experimental model employing the InR(GS15311)/InR(GS50346) strain confirmed negligible involvement of royal jelly in IIS. Thus, the heteroallelic InR mutant, discovered in this study, will serve as a good model for multiple purposes: investigating the IIS mechanisms; identifying and validating the ingredients that prevent type II diabetes; and screening of food constituents associated with IIS.