The Drosophila insulin receptor is required for normal growth

Endocrinology. 1996 Mar;137(3):846-56. doi: 10.1210/endo.137.3.8603594.


Drosophila contain an insulin receptor homologue, encoded by the inr gene located at position 93E4-5 on the third chromosome. The receptor protein is strikingly homologous to the human receptor, exhibiting the same alpha2beta2 subunit structure and containing a ligand- activated tyrosine kinase in its cytoplasmic domain. Chemical mutagenesis was used to induce mutations in the inr gene and six independent mutations that lead to a loss of expression or function of the receptor protein were identified. These mutations are recessive, embryonic, or early larval lethals, but some alleles exhibit heteroallelic complementation to yield adults with a severe developmental delay (10 days), growth-deficiency, female-sterile phenotype. Interestingly, the severity of the mutant phenotype correlates with biochemical measures of loss of function of the receptor tyrosine kinase. The growth deficiency appears to be due to a reduction in cell number, suggesting a role for inr in regulation of cell proliferation during development. The phenotype is reminiscent of those seen in syndromes of insulin-resistance or IGF-I and IGF-I receptor deficiencies in higher organisms, suggesting a conserved function for this growth factor family in the regulation of growth and body size.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles
  • Animals
  • Cell Differentiation
  • Cell Division
  • Drosophila / growth & development*
  • Drosophila / physiology
  • Female
  • Mutation
  • Receptor, Insulin / physiology*


  • Receptor, Insulin