Quantitative live imaging of Venus::BMAL1 in a mouse model reveals complex dynamics of the master circadian clock regulator

• DOI: 10.1371/journal.pgen.1008729
• Publication Date: 2020-04-30T18:12:36Z
• Authors: Nan Yang; Nicola J. Smyllie; Honor Morris; Cátia F. Gonçalves; Michal Dudek; Dharshika R. J. P...; Johanna E. Chesham; Antony Adamson; David G. Spiller; Egor Zindy; James Bagnall; Neil Humphreys; Judith Hoyland; Andrew S. I. Loudon; Michael H. Hastings; Qing-Jun Meng
• Keywords: Oscillating gene; Master clock

Evolutionarily conserved circadian clocks generate 24-hour rhythms in physiology and behaviour that adapt organisms to their daily seasonal environments. In mammals, the suprachiasmatic nucleus (SCN) of hypothalamus is principal co-ordinator cell-autonomous distributed across all major tissues. The importance robust highlighted by experimental epidemiological associations between disruption human diseases. BMAL1 (a bHLH-PAS domain-containing transcription factor) master positive regulator within transcriptional-translational feedback loops (TTFLs) cell-autonomously define time. It drives negative regulators Period Cryptochrome alongside numerous clock output genes, thereby powers time-keeping. Because deletion Bmal1 alone sufficient eliminate cells whole animal it has been widely used as a model for molecular rhythms, revealing essential, tissue-specific roles in, example, brain, liver musculoskeletal system. Moreover, clock-independent functions influence ageing protein translation. Despite essential role time-keeping, direct measures its intra-cellular are still lacking. To fill this knowledge-gap, we CRISPR Cas9 mouse expressing knock-in fluorescent fusion endogenous (Venus::BMAL1) quantitative live imaging physiological settings. Bmal1Venus enabled us visualise quantify core factor central peripheral clocks, with single-cell resolution revealed expression, anti-phasic regulators, nuclear-cytoplasmic mobility abundance.