A Nutrient Sensor Mechanism Controls Drosophila Growth

Cell. 2003 Sep 19;114(6):739-49. doi: 10.1016/s0092-8674(03)00713-x.

Abstract

Organisms modulate their growth according to nutrient availability. Although individual cells in a multicellular animal may respond directly to nutrient levels, growth of the entire organism needs to be coordinated. Here, we provide evidence that in Drosophila, coordination of organismal growth originates from the fat body, an insect organ that retains endocrine and storage functions of the vertebrate liver. In a genetic screen for growth modifiers, we identified slimfast, a gene that encodes an amino acid transporter. Remarkably, downregulation of slimfast specifically within the fat body causes a global growth defect similar to that seen in Drosophila raised under poor nutritional conditions. This involves TSC/TOR signaling in the fat body, and a remote inhibition of organismal growth via local repression of PI3-kinase signaling in peripheral tissues. Our results demonstrate that the fat body functions as a nutrient sensor that restricts global growth through a humoral mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / deficiency
  • Amino Acid Transport Systems / genetics
  • Amino Acid Transport Systems / isolation & purification*
  • Amino Acid Transport Systems / metabolism
  • Amino Acids / deficiency
  • Animals
  • Down-Regulation / physiology
  • Drosophila Proteins / deficiency
  • Drosophila Proteins / genetics
  • Drosophila Proteins / isolation & purification*
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / growth & development*
  • Drosophila melanogaster / metabolism
  • Fat Body / metabolism
  • Feedback, Physiological / genetics
  • Food Deprivation / physiology*
  • Gene Expression Regulation, Developmental / genetics
  • Juvenile Hormones / deficiency
  • Juvenile Hormones / isolation & purification*
  • Juvenile Hormones / metabolism
  • Nutritional Physiological Phenomena / physiology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Signal Transduction / physiology

Substances

  • Amino Acid Transport Systems
  • Amino Acids
  • Drosophila Proteins
  • Juvenile Hormones
  • slif protein, Drosophila
  • Phosphatidylinositol 3-Kinases
  • Receptor Protein-Tyrosine Kinases
  • tor protein, Drosophila