Extension of Life-Span by Loss of CHICO, a <i>Drosophila</i> Insulin Receptor Substrate Protein

TLDR

The insulin/IGF signaling pathway, in which the Drosophila chico gene encodes an insulin receptor substrate, is known to regulate adult longevity—as demonstrated in C. elegans—and the dwarf phenotype of chico mutants is not required for lifespan extension.

Abstract

The Drosophila melanogaster gene chico encodes an insulin receptor substrate that functions in an insulin/insulin-like growth factor (IGF) signaling pathway. In the nematode Caenorhabditis elegans, insulin/IGF signaling regulates adult longevity. We found that mutation of chico extends fruit fly median life-span by up to 48% in homozygotes and 36% in heterozygotes. Extension of life-span was not a result of impaired oogenesis in chico females, nor was it consistently correlated with increased stress resistance. The dwarf phenotype of chico homozygotes was also unnecessary for extension of life-span. The role of insulin/IGF signaling in regulating animal aging is therefore evolutionarily conserved.