Journal Article
Studying the evolution of the vertebrate circadian clock: The power of fish as compataive models
Foulkes, N.S., Whitmore, D., Vallone, D and Bertolucci, C.
Record Number:
2927
Year:
2016
Journal:
Advances in Genetics
Pages:
1-30
Volume:
95
Abstract:
The utility of any model species cannot be judged solely in terms of the tools and
approaches it provides for genetic analysis. A fundamental consideration is also how
its biology has been shaped by the environment and the ecological niche which it
occupies. By comparing different species occupying very different habitats we can learn
how molecular and cellular mechanisms change during evolution in order to optimally
adapt to their environment. Such knowledge is as important as understanding how these mechanisms work. This is illustrated by the use of fish models for studying the
function and evolution of the circadian clock. In this review we outline our current
understanding of how fish clocks sense and respond to light and explain how this
differs fundamentally from the situation with mammalian clocks. In addition, we present
results from comparative studies involving two species of blind cavefish, Astyanax
mexicanus and Phreatichthys andruzzii. This work reveals the consequences of evolution
in perpetual darkness for the circadian clock and its regulation by light as well as for
other mechanisms such as DNA repair, sleep, and metabolism which directly or indirectly
are affected by regular exposure to sunlight. Major differences in the cave habitats
inhabited by these two cavefish species have a clear impact on shaping the
molecular and cellular adaptations to life in complete darkness.
Times Cited:
2