How cells control developmental timetables

 TERESA RAYON HTTPS://ORCID.ORG/0000-0001-5173-1442 Authors Info & Affiliations

Abstract

An overview on the molecular and metabolic mechanisms behind individual cell differences in developmental timing in the segmentation clock and the central nervous system.

From the cell cycle to circadian rhythms, biology relies on precise timing. This includes the duration of a process, the order and direction of events, and the rate at which a process operates. Timing can depend on extrinsic mechanisms that guide the synchronous progression through development of a group of cells via systemic cues. However, timing also relies on intrinsic mechanisms that keep track of time within cells. A focus on developmental timing is gaining momentum, as researchers tease out the molecular and metabolic mechanisms responsible for it.

In evolutionary developmental biology, differences in genetically controlled temporal programs are well recognized and referred to as heterochronies. These include differences in the time of initiation, duration, or rate of a process in comparison with an organisms’ ancestors or other species. Whereas shifts in the time of initiation or duration have been linked to genetic variation of regulatory sequences or differential expression dynamics (1, 2), other heterochronies that emerge from changes in the rate of a process are distinct and usually involve the same genetic program operating at different speeds. This has been termed allochrony and does not seem to be explained by variations in regulatory sequences (Fig. 1, A to C) (3, 4). However, less is known about the mechanisms driving allochronies. ...

https://www.science.org/doi/10.1126/sciadv.adh1849