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

4.0K
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...
4.0K
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

34.6K
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.
34.6K
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences01:17

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

762
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
762

You might also read

Related Articles

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

Sort by
Same author

Switching from insertion to conversion for multielectron aqueous vanadium batteries.

Nature materials·2026
Same author

Genome-Scale Metabolic Modeling of Terpenoid Biosynthesis: Advances and Perspectives.

Journal of agricultural and food chemistry·2026
Same author

Therapeutic potential of ELABELA in alleviating hereditary hypertrophic cardiomyopathy.

Journal of advanced research·2026
Same author

Single-nucleus transcriptomics resolves multiple fate dynamics between inflorescence meristem and primary stem.

Science advances·2026
Same author

Tmem67 Is Required for Spermiogenesis and Male Fertility in Mice.

FASEB journal : official publication of the Federation of American Societies for Experimental Biology·2026
Same author

Establishment of a rapid and highly sensitive direct-RAA-RDB detection platform: application in non-deletion α-thalassemia.

Frontiers in molecular biosciences·2026

Related Experiment Video

Updated: Jun 6, 2025

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

12.8K

The cyanobacterial circadian clock couples to pulsatile processes using pulse amplitude modulation.

Chao Ye1, Chris N Micklem2, Teresa Saez2

  • 1Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge CB2 1LR, UK; School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.

Current Biology : CB
|November 26, 2024
PubMed
Summary

Cyanobacteria use pulse amplitude modulation (PAM) to link their cell cycle and circadian clock. This mechanism ensures robust 24-hour gene expression rhythms, even when gene pulses are irregular.

Keywords:
Synechococcus elongatus PCC 7942cell divisioncell sizecircadian clockcyanobacteriagene expression pulsingpulse amplitude modulationsigma factorssingle-cell live imagingsystems biology

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

9.7K
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

22.3K

Related Experiment Videos

Last Updated: Jun 6, 2025

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

12.8K
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

9.7K
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

22.3K

Area of Science:

  • Cellular Biology
  • Systems Biology
  • Circadian Rhythms

Background:

  • Cellular processes are dynamic and often oscillatory, requiring precise coordination.
  • Coupling distinct oscillatory processes within a single cell is a key challenge.
  • The cyanobacterial circadian clock times daily processes via gene expression oscillations.

Purpose of the Study:

  • To explore the coupling of oscillatory and pulsatile gene circuits using the cyanobacterial circadian clock.
  • To investigate how the circadian clock modulates pulsatile gene expression.
  • To determine the functional significance of RpoD4 expression in cyanobacteria.

Main Methods:

  • Single-cell time-lapse microscopy.
  • Mathematical modeling of gene circuits.
  • Genetic manipulation (gene deletion and altered expression levels).

Main Results:

  • The circadian clock modulates the amplitude of RpoD4 expression pulses, which occur at cell division.
  • Pulse amplitude modulation (PAM) enables robust 24-hour rhythms in RpoD4 expression despite non-circadian pulse frequencies.
  • RpoD4 expression levels are linked to cell size in a dose-dependent manner.

Conclusions:

  • A link exists between the cell cycle, circadian clock, and RpoD4 in cyanobacteria.
  • PAM is a mechanism for biological clocks to robustly modulate pulsatile downstream processes.
  • The study reveals how cellular timing mechanisms integrate cell cycle events with circadian regulation.