The Development and Decay of the Circadian Clock in Drosophila melanogaster

Abstract

The way in which the circadian clock mechanism develops and decays throughout life is interesting for a number of reasons and may give us insight into the process of aging itself. The Drosophila model has been proven invaluable for the study of the circadian clock and development and aging. Here we review the evidence for how the Drosophila clock develops and changes throughout life, and present a new conceptual model based on the results of our recent work. Firefly luciferase lines faithfully report the output of known clock genes at the central clock level in the brain and peripherally throughout the whole body. Our results show that the clock is functioning in embryogenesis far earlier than previously thought. This central clock in the fly remains robust throughout the life of the animal and only degrades immediately prior to death. However, at the peripheral (non-central oscillator level) the clock shows weakened output as the animal ages, suggesting the possibility of the breakdown in the cohesion of the circadian network.

Daily temperature cycles prolong lifespan and have sex-specific effects on peripheral clock gene expression in Drosophila melanogaster

“…high-amplitude) circadian rhythms are associated with resilience to shift work in humans (Reinberg et al, 1980), and better metabolic health (He et al, 2016;Katewa et al, 2016) and longevity (Hurd and Ralph, 1998;Katewa et al, 2016) in rodents and D. melanogaster. In addition, ageing is associated with a progressive weakening of circadian rhythmicity, an outcome that is highly conserved in mammals, fish and insects (Hood and Amir, 2017;Kunieda et al, 2006;Stankiewicz et al, 2017;Zhao et al, 2019). Therefore, the manipulation of cues that entrain the amplitude of clock gene expression could have beneficial effects in both mammals and insects.…”

Getting into rhythm: developmental emergence of circadian clocks and behaviors

“…A key question in chronobiology is how the core circadian clock network emerges during animal development and how its development is tied to the emergence of behavioral and physiological rhythms. Here we will briefly describe clock ontogeny in mammals and zebrafish (see Vallone 2007 [21], Landgraf 2014 [22], Zhao 2019 [23]) before providing a more extensive review of its development in flies.…”