Drosophila fragile X protein, DFXR, regulates neuronal morphology and function in the brain

Neuron. 2002 Jun 13;34(6):961-72. doi: 10.1016/s0896-6273(02)00731-6.


Mental retardation is a pervasive societal problem, 25 times more common than blindness for example. Fragile X syndrome, the most common form of inherited mental retardation, is caused by mutations in the FMR1 gene. Fragile X patients display neurite morphology defects in the brain, suggesting that this may be the basis of their mental retardation. Drosophila contains a single homolog of FMR1, dfxr (also called dfmr1). We analyzed the role of dfxr in neurite development in three distinct neuronal classes. We find that DFXR is required for normal neurite extension, guidance, and branching. dfxr mutants also display strong eclosion failure and circadian rhythm defects. Interestingly, distinct neuronal cell types show different phenotypes, suggesting that dfxr differentially regulates diverse targets in the brain.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / pathology
  • Brain / physiology*
  • Circadian Rhythm / genetics
  • Circadian Rhythm / physiology
  • Drosophila Proteins / physiology*
  • Fragile X Mental Retardation Protein
  • Fragile X Syndrome / genetics*
  • Molecular Sequence Data
  • Motor Activity / genetics
  • Motor Activity / physiology
  • Mutation
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Neuroglia / metabolism
  • Neuroglia / pathology
  • Neuroglia / physiology
  • Neurons / cytology*
  • Neurons / pathology
  • Neurons / physiology
  • RNA-Binding Proteins*
  • Sequence Homology, Amino Acid


  • Drosophila Proteins
  • Nerve Tissue Proteins
  • RNA-Binding Proteins
  • Fragile X Mental Retardation Protein