Identifying sleep regulatory genes using a Drosophila model of insomnia

J Neurosci. 2009 Jun 3;29(22):7148-57. doi: 10.1523/JNEUROSCI.5629-08.2009.

Abstract

Although it is widely accepted that sleep must serve an essential biological function, little is known about molecules that underlie sleep regulation. Given that insomnia is a common sleep disorder that disrupts the ability to initiate and maintain restorative sleep, a better understanding of its molecular underpinning may provide crucial insights into sleep regulatory processes. Thus, we created a line of flies using laboratory selection that share traits with human insomnia. After 60 generations, insomnia-like (ins-l) flies sleep 60 min a day, exhibit difficulty initiating sleep, difficulty maintaining sleep, and show evidence of daytime cognitive impairment. ins-l flies are also hyperactive and hyperresponsive to environmental perturbations. In addition, they have difficulty maintaining their balance, have elevated levels of dopamine, are short-lived, and show increased levels of triglycerides, cholesterol, and free fatty acids. Although their core molecular clock remains intact, ins-l flies lose their ability to sleep when placed into constant darkness. Whole-genome profiling identified genes that are modified in ins-l flies. Among those differentially expressed transcripts, genes involved in metabolism, neuronal activity, and sensory perception constituted over-represented categories. We demonstrate that two of these genes are upregulated in human subjects after acute sleep deprivation. Together, these data indicate that the ins-l flies are a useful tool that can be used to identify molecules important for sleep regulation and may provide insights into both the causes and long-term consequences of insomnia.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Analysis of Variance
  • Animals
  • Animals, Genetically Modified
  • Avoidance Learning / physiology
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Behavior, Animal
  • Cholesterol / metabolism
  • Circadian Rhythm / genetics
  • Contractile Proteins / metabolism
  • Disease Models, Animal
  • Dopamine / metabolism
  • Drosophila
  • Drosophila Proteins / genetics*
  • Fatty Acids, Nonesterified / metabolism
  • Female
  • Filamins
  • Gene Expression Profiling / methods
  • Gene Expression Regulation / physiology*
  • Humans
  • Lipids
  • Locomotion / genetics
  • Malate Dehydrogenase / metabolism
  • Male
  • Microfilament Proteins / metabolism
  • Neurotransmitter Agents / metabolism
  • Oligonucleotide Array Sequence Analysis / methods
  • Peptide Hormones / genetics
  • Peptide Hormones / metabolism
  • Phenotype
  • Sleep / genetics*
  • Sleep Deprivation / physiopathology
  • Sleep Initiation and Maintenance Disorders / genetics*
  • Statistics, Nonparametric
  • Stress, Psychological / genetics
  • Triglycerides / metabolism
  • Wakefulness

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Contractile Proteins
  • Drosophila Proteins
  • Fatty Acids, Nonesterified
  • Filamins
  • Lipids
  • Microfilament Proteins
  • Neurotransmitter Agents
  • Peptide Hormones
  • Triglycerides
  • Cholesterol
  • Malate Dehydrogenase
  • malic enzyme 2; human
  • Dopamine