Conference Paper
Convergent evolution of sleep loss
Keene, A.
Record Number:
3087
Year:
2015
Journal:
AIM 2015
Abstract:
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 provides a powerful model for elucidating
the genetic mechanisms underlying behavioral evolution. 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. 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. While the genetic and neural mechanisms underlying sleep
loss are distinct from those regulating VAB, ablation of the entire lateral line with
gentamicin, or localized ablation of superficial neuromasts in the head or trunk regions
restore surface fish levels of sleep in Pachón cavefish. Strikingly, ablation of the lateral
line has no effect on sleep in surface or other cave populations suggesting the evolution
of a wake-promoting role for the lateral line in Pachón cavefish. Analysis of surface-
Pachón-cave F2 hybrid fish reveal sleep is inversely related to the number of superficial
neuromasts in the head or trunk, fortifying the notion that sleep loss in Pachón is linked
to increased sensitivity of the lateral line. Taken together, these findings present
Mexican cavefish as a model for understanding the evolutionary changes in sleep and
provide insight into the relationship between sleep and the gating of sensory information.
Current research is seeking to identify the genetic basis for lateral line-dependent sleep
loss in Pachón cavefish
Times Cited:
1
Relevent Species: