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Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
An inherited functional circadian clock in zebrafish embryos
F Delaunay1, C Thisse, O Marchand
1Ecole Normale Supérieure, CNRS UMR 5665, 46 allée d'Italie, 69364 Lyon Cedex, France.
Science (New York, N.Y.)
|July 15, 2000
Summary
The zebrafish circadian clock functions during early embryogenesis, with the Period3 (Per3) gene showing rhythmic expression. Maternal Per3 inheritance may explain how the clock is passed through generations.
Area of Science:
- Developmental Biology
- Chronobiology
- Genetics
Background:
- Circadian clocks are endogenous time-keeping systems crucial for regulating physiological processes in most organisms.
- The Period3 (Per3) gene is a key component of the molecular machinery underlying circadian rhythms.
- Understanding the onset and inheritance of circadian rhythms during embryonic development is fundamental.
Purpose of the Study:
- To investigate the functional status of the circadian clock during early zebrafish embryogenesis.
- To determine the role of light and developmental temperature in resetting the embryonic circadian clock.
- To explore the contribution of maternal factors to the inheritance of circadian rhythms.
Main Methods:
- Quantitative analysis of Per3 gene expression patterns in zebrafish embryos at various developmental stages.
- Exposure of embryos to different light-dark cycles and temperature conditions to assess clock resetting.
- Analysis of Per3 messenger RNA accumulation in oocytes and early embryos.
Main Results:
- Per3 expression exhibited robust circadian rhythms in the central nervous system and retina of zebrafish embryos.
- The embryonic Per3 rhythm was free-running, entrainable by light, but insensitive to developmental delays induced by low temperatures.
- Per3 messenger RNA was rhythmically accumulated in oocytes and persisted in early embryos, indicating maternal contribution.
Conclusions:
- The circadian clock is functional and operative during early zebrafish embryogenesis.
- Light serves as a primaryZeitgeber for the embryonic clock, while developmental temperature does not reset its phase.
- Maternal inheritance of clock gene products, such as Per3, likely provides a mechanism for phase inheritance through ovogenesis.
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