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

•We discovered a novel heteroallelic Drosophila insulin-like receptor (InR) mutant.•This mutant shows phenotypes previously reported in InR without losing fertility.•This mutant grows into adult and might be a good model for type II diabetes.•We confirmed that InR was not involved in the effects of royal jelly bioactivity. Here we report an additional Drosophila transheterozygote InRGS15311/InRGS50346 carrying two different P-element-inducible alleles of insulin-like receptor gene (InR). InRGS15311/InRGS50346 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 InRGS15311/InRGS50346 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.