title: Distinct genetic architecture underlies the emergence of sleep loss and prey-seeking behavior in the Mexican cavefish.
abstract: BACKGROUND
  Sleep is characterized by extended periods of quiescence and reduced responsiveness to sensory stimuli. Animals ranging from insects to mammals adapt to environments with limited food by suppressing sleep and enhancing their response to food cues, yet little is known about the genetic and evolutionary relationship between these processes. The blind Mexican cavefish, Astyanax mexicanus is a powerful model for elucidating the genetic mechanisms underlying behavioral evolution. A. mexicanus comprises an extant ancestral-type surface dwelling morph and at least five independently evolved cave populations. Evolutionary convergence on sleep loss and vibration attraction behavior, which is involved in prey seeking, have been documented in cavefish raising the possibility that enhanced sensory responsiveness underlies changes in sleep.
  
  
  RESULTS
  We established a system to study sleep and vibration attraction behavior in adult A. mexicanus and used high coverage quantitative trait loci (QTL) mapping to investigate the functional and evolutionary relationship between these traits. Analysis of surface-cave F2 hybrid fish and an outbred cave population indicates that independent genetic factors underlie changes in sleep/locomotor activity and vibration attraction behavior. High-coverage QTL mapping with genotyping-by-sequencing technology identify two novel QTL intervals that associate with locomotor activity and include the narcolepsy-associated tp53 regulating kinase. These QTLs represent the first genomic localization of locomotor activity in cavefish and are distinct from two QTLs previously identified as associating with vibration attraction behavior.
  
  
  CONCLUSIONS
  Taken together, these results localize genomic regions underlying sleep/locomotor and sensory changes in cavefish populations and provide evidence that sleep loss evolved independently from enhanced sensory responsiveness.
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, NV, 89557, USA. yoshizaw@hawaii.edu.|Department of Biology, University of Hawaii, Manoa, Honolulu, HI, 96822, USA. yoshizaw@hawaii.edu.
authors.forename: Masato
authors.initials: M
authors.lastname: Yoshizawa
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, NV, 89557, USA. beatrizrobinson93@gmail.com.
authors.forename: Beatriz G
authors.initials: BG
authors.lastname: Robinson
authors.affiliation: Department of Biology, New York University, New York, NY, 10012, USA. duboue@ciwemb.edu.|Present address: Carnegie Institution for Science, Department of Embryology, Baltimore, MD, 21218, USA. duboue@ciwemb.edu.
authors.forename: Erik R
authors.initials: ER
authors.lastname: Duboué
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, NV, 89557, USA. pmasek@unr.edu.
authors.forename: Pavel
authors.initials: P
authors.lastname: Masek
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, NV, 89557, USA. jbrianjaggard@gmail.com.
authors.forename: James B
authors.initials: JB
authors.lastname: Jaggard
authors.affiliation: Department of Biology, Centre College, Danville, KY, 40422, USA. kellyoquin@gmail.com.
authors.forename: Kelly E
authors.initials: KE
authors.lastname: O'Quin
authors.affiliation: Department of Biology, New York University, New York, NY, 10012, USA. rb4@nyu.edu.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Borowsky
authors.affiliation: Department of Biology, University of Maryland, College Park, MD, 20742, USA. Jeffery@umd.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: Jeffery
authors.affiliation: Department of Biology, University of Nevada, Reno, Reno, NV, 89557, USA. akeene@unr.edu.
authors.forename: Alex C
authors.initials: AC
authors.lastname: Keene
mesh_terms: D000818:Animals; D005075:Biological Evolution; D059552:Caves; D060126:Characidae / Q000235:genetics*; D003433:Crosses, Genetic; D005260:Female; D006824:Hybridization, Genetic; D008124:Locomotion; D008297:Male; D008800:Mexico; D011235:Predatory Behavior / Q000502:physiology*; D040641:Quantitative Trait Loci / Q000235:genetics; D012890:Sleep; D012892:Sleep Deprivation / Q000235:genetics*; D014732:Vibration