Circadian biology

Circadian biology studies ~24-hour endogenous rhythms that synchronise physiology and behaviour with the day–night cycle.

Circadian clocks organise physiology across kingdoms; clean experimental systems make them teachable.

Claim ledger

What the evidence shows

Drawn from 5 studies in this library. Mix labels say which citation roles are present; they are not a strength score. Supports means evidence for a finding; Challenges means evidence against a stated position; Qualifies marks scope.

• ● Supporting studies only

  Multiple empirical papers in this library examine circadian biology with mechanistic biological findings.

  3 studies
  1. 1How does food reset the liver clock?
  2. 2CK1ε, PERIOD2, and cancer-selective growth arrest
  3. 3Does light control fungal cellulase genes?

  Study comparison

  Study	Role	Design	N	Population	Outcome
  How does food reset the liver clock?2015	Supports	Animal / in-vitroOrganotypic liver-slice and in-vivo assays of food-related OXM as a liver-clock Zeitgeber	Mouse liver-clock resetting experiments — no single primary analytic N in stored text	Mouse liver tissue/slices and related in-vivo models	Hepatic circadian clock resetting by oxyntomodulin
  CK1ε, PERIOD2, and cancer-selective growth arrest2008	Supports	Animal / in-vitroKinase shRNA library screen and CK1ε inhibitor assays in isogenic cancer vs normal cells	Library targets 1,006 genes; cell-line dependency study — no single sample N	Isogenic cancer and normal cell models	Cancer-selective, PERIOD2-dependent growth arrest after CSNK1E/CK1ε inhibition
  Does light control fungal cellulase genes?2012	Supports	Animal / in-vitroCellulase transcription profiling in photoreceptor mutants under light regimes	Fungal photoreceptor mutant expression study — no single sample N in stored text	Fungi with WC-1/WC-2/VVD photoreceptor pathways	Light modulation of cellulase gene expression via photoreceptors

• ○ Limited citations

  OXM can couple food intake to hepatic clock resetting; eating in the rest phase risks internal circadian desynchrony relevant to shiftwork metabolism.

  1 study
  1. 1How does food reset the liver clock?

• ○ Limited citations

  CSNK1E is a cancer-preferential dependency; CK1ε inhibitors phenocopy shRNA, and growth arrest is PERIOD2-dependent.

  1 study
  1. 1CK1ε, PERIOD2, and cancer-selective growth arrest

• ○ Limited citations

  WC-1, WC-2 and VVD affect cellulase gene expression; light modulation of cellulases appears conserved, likely advantageous in nature.

  1 study
  1. 1Does light control fungal cellulase genes?

• ○ Limited citations

  Known clock genes cycle as expected; many additional exons/ncRNA features show circadian rhythms.

  1 study
  1. 1Tiling arrays reveal plant circadian RNAs

Debates

Tensions and limits

Some items are genuine disagreements on the same question. Others mark different assays, populations, or outcomes.

Timeline

How understanding moved

Study years are when the paper was published. Evidence edits are dated changes to this page's claims. Explanations are when PaperFren added a Discovery — not a claim that the science happened that day.

Papers

5 studies in this library bear on Circadian biology, ordered by citations.

• Does the plant clock gate auxin responses?

  The Arabidopsis circadian clock regulates auxin-responsive transcription and gates growth responses to auxin.

  PLoS biology · 2007 · 282 citations

• Tiling arrays reveal plant circadian RNAs

  Genome tiling arrays uncover extensive circadian-regulated transcription across the Arabidopsis genome.

  Genome biology · 2009 · 93 citations

• How does food reset the liver clock?

  The gut incretin oxyntomodulin (OXM) links food intake to resetting of the hepatic circadian clock and metabolism.

  eLife · 2015 · 88 citations

• CK1ε, PERIOD2, and cancer-selective growth arrest

  Cancer cells depend more than normal cells on casein kinase 1-epsilon; inhibiting CK1ε causes PERIOD2-dependent growth arrest.

  Genome biology · 2008 · 76 citations

• Does light control fungal cellulase genes?

  Neurospora photoreceptors WC-1, WC-2 and VVD influence cellulase expression; light-modulated cellulase regulation is conserved in filamentous fungi.

  BMC genomics · 2012 · 58 citations

Questions

What is still open

1. Systems and scales differ across circadian biology studies (species, tissues, methods), so mechanisms should not be over-generalised.

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Ask PaperFren about Circadian biology