Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

4.7K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.7K
Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

2.5K
2.5K
Bacterial Phylum Cyanobacteria01:30

Bacterial Phylum Cyanobacteria

863
Cyanobacteria are a diverse group of oxygenic, phototrophic bacteria that played a pivotal role in converting Earth’s atmosphere from anoxic to oxygen-rich billions of years ago. They exhibit remarkable morphological diversity, ranging from unicellular forms to filamentous types, with cell sizes varying between 0.5 μm and 100 μm. Cyanobacteria are classified into five groups: Chroococcales (unicellular, dividing by binary fission), Pleurocapsales (unicellular, dividing by...
863
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

42.1K
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
42.1K
Anoxygenic Photosynthesis01:30

Anoxygenic Photosynthesis

1.7K
Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green...
1.7K
The Calvin Benson Cycle01:46

The Calvin Benson Cycle

7.8K
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
7.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Effects of the signaling molecule cyclic-di-GMP on cyanobacterial circadian rhythm in <i>Synechococcus elongatus</i> PCC 7942.

Journal of bacteriology·2026
Same author

Mechanism and reconstitution of circadian transcription in cyanobacteria.

Nature structural & molecular biology·2026
Same author

Circadian clock proteins KaiB and Rbp2 of <i>Synechococcus elongatus</i> display oscillations in their subcellular localization patterns.

Microbiology spectrum·2025
Same author

A homolog of methionine γ-lyase is required for biofilm development in the cyanobacterium Synechococcus elongatus.

World journal of microbiology & biotechnology·2025
Same author

Nurse led telephonic palliative care versus specialty outpatient palliative care: pragmatic, randomised clinical trial.

BMJ medicine·2025
Same author

Robert Haselkorn (1934-2025): Pioneer in molecular biology and microbiology.

Proceedings of the National Academy of Sciences of the United States of America·2025

Related Experiment Video

Updated: Apr 4, 2026

Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter
07:42

Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter

Published on: September 17, 2016

13.5K

Circadian Rhythms in Cyanobacteria.

Susan E Cohen1, Susan S Golden2

  • 1Center for Circadian Biology and Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA susanc@ucsd.edu.

Microbiology and Molecular Biology Reviews : MMBR
|September 4, 2015
PubMed
Summary
This summary is machine-generated.

Circadian rhythms, controlled by a biological clock, help organisms adapt to daily environmental changes. This study details the molecular clock mechanism in cyanobacteria, revealing a complex network for timekeeping.

More Related Videos

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.5K
Analysis of Circadian Photoresponses in Drosophila Using Locomotor Activity
00:08

Analysis of Circadian Photoresponses in Drosophila Using Locomotor Activity

1.5K

Related Experiment Videos

Last Updated: Apr 4, 2026

Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter
07:42

Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter

Published on: September 17, 2016

13.5K
In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.5K
Analysis of Circadian Photoresponses in Drosophila Using Locomotor Activity
00:08

Analysis of Circadian Photoresponses in Drosophila Using Locomotor Activity

1.5K

Area of Science:

  • Microbiology
  • Molecular Biology
  • Chronobiology

Background:

  • Life on Earth exhibits circadian rhythms, biological processes synchronized with daily environmental cycles like light and temperature.
  • These rhythms are regulated by an internal circadian clock, crucial for adapting cellular physiology to predictable environmental fluctuations.
  • Circadian clocks are widespread, found in both prokaryotic and eukaryotic organisms, indicating their fundamental biological importance.

Purpose of the Study:

  • To elucidate the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942.
  • To review and synthesize current understanding of the cyanobacterial clock, focusing on environmental synchronization and output pathways.
  • To explore the network properties of the circadian oscillator and its integration within the cellular context.

Main Methods:

  • Detailed molecular analysis of the circadian clock components in Synechococcus elongatus PCC 7942.
  • Review of recent experimental work on cyanobacterial circadian rhythms.
  • Comparative analysis of circadian mechanisms across different cyanobacterial species.

Main Results:

  • The study presents a comprehensive understanding of the molecular clock in Synechococcus elongatus PCC 7942.
  • It highlights how the circadian oscillator synchronizes with external cues and transmits timing information.
  • The findings support a shift from a linear clock model to a network model with multifunctional components.

Conclusions:

  • The cyanobacterial circadian clock operates as an interactive network, not a simple linear system.
  • Understanding this mechanism provides insights into cellular adaptation and temporal regulation in prokaryotes.
  • This work facilitates the translation of findings from cyanobacteria to other prokaryotic systems exhibiting rhythmic phenomena.