Cut the noise or couple up: Coordinating circadian and synthetic clocks

Abstract

Circadian clocks are important to much of life on Earth and are of inherent interest to humanity, implicated in fields ranging from agriculture and ecology to developmental biology and medicine. New techniques show that it is not simply the presence of clocks, but coordination between them that is critical for complex physiological processes across the kingdoms of life. Recent years have also seen impressive advances in synthetic biology to the point where parallels can be drawn between synthetic biological and circadian oscillators. This review will emphasize theoretical and experimental studies that have revealed a fascinating dichotomy of coupling and heterogeneity among circadian clocks. We will also consolidate the fields of chronobiology and synthetic biology, discussing key design principles of their respective oscillators.

The seasons within: a theoretical perspective on photoperiodic entrainment and encoding

“…Besides coupled SCN neurons in the mammalian core pacemaker, communicating circadian clocks have been described in and between peripheral tissues as well. Density dependent rhythmicity in cultured fibroblasts (Noguchi et al 2013) and hepatocytes (Guenthner et al 2014) is indicative of coupling (Micklem and Locke 2021). In addition, mathematical modeling suggests that the choroid plexus, a non-neuronal brain tissue that harbors a robust clock more precise than the SCN gains its high precision through nearest neighbor gap junctional coupling .…”

“…Interlocked transcriptional translational negative feedback loops are a common design principle underlying single cellular rhythm generation across different species such as Neurospora crassa, plants, insects and mammals. Such single cellular oscillators coordinate at the tissue and organ level to ensure a proper system level functioning of circadian physiology (Micklem and Locke 2021). A functioning circadian clockwork has been shown to provide an adaptive advantage across different kingdoms of life, ranging from unicellular cyanobacteria to multicellular plants and mammals (Ouyang et al 1998;Dodd et al 2005;Spoelstra et al 2016).…”

Spatially specific mechanisms and functions of the plant circadian clock

“…Rather than being a single timekeeper, multiple studies are revealing specialization in regulation and function for the clock across the plant. We will only briefly describe mechanisms for local and long-distance coordination of plant clock rhythms as these have recently been extensively reviewed ( Micklem and Locke, 2021 ; Nohales, 2021 ; Sorkin and Nusinow, 2021 ). Instead, we will focus on how the clock architecture is altered across the plant, our understanding of spatially specific functions, and what implications these have for our understanding of how the clock can increase fitness.…”

Coupled and Synchronization Models of Rhythmic Arm Movement in Planar Plane

“…Nonlinear oscillators have been used to interpret biological systems, which are commonly related directly or indirectly to physiological rhythms, such as circadian clocks [ 17 ], physiological stress [ 18 ], and bipolar disorder [ 19 ]. The coupled system and synchronization are very common phenomena in biological systems, which typically exhibit rhythmic behaviors.…”