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Published on: June 3, 2020
Diurnally entrained anticipatory behavior in archaea
Kenia Whitehead1, Min Pan, Ken-ichi Masumura
1Institute for Systems Biology, Seattle, Washington, United States of America.
Plos One
|May 9, 2009
Summary
This study reveals diurnal gene transcription in the archaeon Halobacterium salinarum, demonstrating anticipatory behavior previously unobserved in this domain. These findings suggest a strategy for optimizing physiology in response to environmental cues.
Area of Science:
- Microbiology
- Molecular Biology
- Environmental Science
Background:
- Biological systems often anticipate environmental changes using cues like light-dark cycles.
- Diurnal rhythms are common in eukaryotes and some bacteria but have not been documented in archaea.
- Understanding archaeal responses to environmental cycles is crucial for comprehending microbial ecology.
Purpose of the Study:
- To investigate the presence and characteristics of diurnal gene transcription in the halophilic archaeon Halobacterium salinarum.
- To determine if Halobacterium salinarum exhibits free-running rhythms after light-dark entrainment.
- To explore the link between diurnal entrainment and the synchronization of oxic and anoxic physiologies.
Main Methods:
- Utilized light-dark (LD) entrainment to study gene transcription patterns in Halobacterium salinarum NRC-1.
- Monitored gene expression under constant darkness to observe free-running rhythms.
- Analyzed the synchronization of oxic and anoxic metabolic processes with the LD cycle.
Main Results:
- Observed light-dark (LD)-entrained diurnal oscillatory transcription in up to 12% of genes in Halobacterium salinarum.
- Demonstrated free-running diurnal rhythms in gene expression under constant darkness, indicating a biological memory of entrainment.
- Found synchronization of oxic and anoxic physiologies to the LD cycle.
Conclusions:
- Halobacterium salinarum exhibits diurnal gene transcription and physiological synchronization, a novel finding for archaea.
- The archaeon appears to leverage sunlight's influence on oxygen diffusivity to optimize its metabolism, being oxic at night and anoxic during the day.
- This anticipatory behavior likely enhances fitness in nutrient-limited, hypersaline environments.
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