Journal Article
Cavefishes in chronobiological research: A narrative review.
Pavlova, V.V. and Krylov, V.V.
Record Number:
6084
Year:
2023
Journal:
Clocks and Sleep
Pages:
62-71
Volume:
5
Notes:
Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons
Attribution (CC BY) license (https:// creativecommons.org/licenses/by/4.0/).
Abstract:
Abstract: Cavefish are vertebrates living in extreme subterranean environments with no light, temperature
changes, and limited food. Circadian rhythms in these fish are suppressed in natural habitats.
However, they can be found in artificial light–dark cycles and other zeitgebers. The molecular
circadian clock has its peculiarities in cavefish. In Astyanax mexicanus, the core clock mechanism
is tonically repressed in the caves due to the overactivation of the light input pathway. A lack of
functional light input pathway but rather the entrainment of circadian genes’ expression by scheduled
feeding were revealed in more ancient Phreatichthys andruzzii. Different evolutionarily determined
irregularities in the functioning of molecular circadian oscillators can be expected in other cavefish.
The unique property of some species is the existence of surface and cave forms. Along with the ease
of maintenance and breeding, it made cavefish a promising model for chronobiological studies. At
the same time, a divergence of the circadian system between cavefish populations requires the strain
of origin to be indicated in further research.
Keywords: Astyanax mexicanus; circadian clock; behavior; rhythm; caves; light–dark cycle
Times Cited:
2