title: Genetic background has a major impact on differences in sleep resulting from environmental influences in Drosophila.
abstract: OBJECTIVE
  To determine the effect of different genetic backgrounds on demographic and environmental interventions that affect sleep and evaluate variance of these measures; and to evaluate sleep and variance of sleep behaviors in 6 divergent laboratory strains of common origin.
  
  
  METHODS
  Assessment of the effects of age, sex, mating status, food sources, and social experience using video analysis of sleep behavior in 2 different strains of Drosophila, white(1118ex) (w(1118ex)) and white Canton-S (w(CS10)). Sleep was also determined for 6 laboratory strains of Canton-S and 3 inbred lines. The variance of total sleep was determined for all groups and conditions.
  
  
  RESULTS
  The circadian periods and the effects of age upon sleep were the same between w(1118ex) and w(CS10) strains. However, the w(1118ex) and w(CS10) strains demonstrated genotype-dependent differences in the effects upon sleep of sex, mating status, social experience, and being on different foods. Variance of total sleep was found to differ in a genotype dependent manner for interventions between the w(1118ex) and w(CS10) strains. Six different laboratory Canton-S strains were found to have significantly different circadian periods (P < 0.001) and sleep phenotypes (P < 0.001). Three inbred lines showed reduced variance for sleep measurements.
  
  
  CONCLUSIONS
  One must control environmental conditions in a rigorously consistent manner to ensure that sleep data may be compared between experiments. Genetic background has a significant impact upon changes in sleep behavior and variance of behavior due to demographic factors and environmental interventions. This represents an opportunity to discover new genes that modify sleep/wake behavior.
authors.affiliation: Center for Sleep & Circadian Neurobiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-3403, USA. johnez@mail.med.upenn.edu
authors.forename: John E
authors.initials: JE
authors.lastname: Zimmerman
authors.forename: May T
authors.initials: MT
authors.lastname: Chan
authors.forename: Nicholas
authors.initials: N
authors.lastname: Jackson
authors.forename: Greg
authors.initials: G
authors.lastname: Maislin
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
mesh_terms: D000818:Animals; D001143:Arousal / Q000235:genetics; D001522:Behavior, Animal / Q000502:physiology*; D002940:Circadian Rhythm / Q000235:genetics; D004330:Drosophila; D005260:Female; D059647:Gene-Environment Interaction; D005838:Genotype; D008297:Male; D012890:Sleep / Q000235:genetics*; D014741:Video Recording