title: Natural variation in Drosophila stressed locomotion meets or exceeds variation caused by hsp70 mutation: analysis of behavior and performance.
abstract: Thermotolerance involves more than life or death. Investigating the complexity of this trait will aid identification of its genetic contributors. We examined variation in thermally stressed walking behavior and performance in natural Drosophila melanogaster strains and strains mutant for the heat shock protein Hsp70, to determine which aspects of locomotion are affected by heat shock and genotype. We developed software for the large-scale capture, analysis, and visualization of locomotion, and determined: (1) Heat shock and thermal pretreatment significantly and differentially impact fly locomotor behavior and performance. (2) Stressed locomotion traits vary extensively among natural strains. (3) Interactions among treatments, strains, and traits are substantial and often counterintuitive. (4) Hsp70 overexpressing flies are faster and more basally thermoprotected in performance than Hsp70 null flies, but null flies are more unidirectional. (5) Natural variation in most stressed locomotion traits exceeds that caused by Hsp70 mutation, reveals uncoupling between thermoprotection of behavior and performance, and suggests significant genetic variation for trait-specific modifiers of thermotolerance.
authors.affiliation: Department of Biological Sciences, University of Massachusetts Lowell, 1 University Ave, Lowell, MA 01854, USA. Brian_Bettencourt@uml.edu
authors.forename: Brian R
authors.initials: BR
authors.lastname: Bettencourt
authors.forename: Brian W
authors.initials: BW
authors.lastname: Drohan
authors.forename: Andrea T
authors.initials: AT
authors.lastname: Ireland
authors.forename: Mahalakshmi
authors.initials: M
authors.lastname: Santhanam
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Smrtic
authors.forename: Erin M
authors.initials: EM
authors.lastname: Sullivan
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D004252:DNA Mutational Analysis; D004331:Drosophila melanogaster; D005260:Female; D015870:Gene Expression / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D006185:Habituation, Psychophysiologic / Q000235:genetics; D054643:INDEL Mutation; D007091:Image Processing, Computer-Assisted; D008124:Locomotion / Q000235:genetics*; D008297:Male; D011930:Reaction Time / Q000235:genetics; D012984:Software; D013312:Stress, Physiological / Q000235:genetics*; D016019:Survival Analysis; D013697:Thermosensing / Q000235:genetics*; D014743:Videotape Recording
chemical_list: D018840:HSP70 Heat-Shock Proteins