16 research outputs found
Kernel Architecture of the Genetic Circuitry of the Arabidopsis Circadian System
A wide range of organisms features molecular machines, circadian clocks,
which generate endogenous oscillations with ~24 h periodicity and thereby
synchronize biological processes to diurnal environmental fluctuations.
Recently, it has become clear that plants harbor more complex gene regulatory
circuits within the core circadian clocks than other organisms, inspiring a
fundamental question: are all these regulatory interactions between clock genes
equally crucial for the establishment and maintenance of circadian rhythms? Our
mechanistic simulation for Arabidopsis thaliana demonstrates that at least half
of the total regulatory interactions must be present to express the circadian
molecular profiles observed in wild-type plants. A set of those essential
interactions is called herein a kernel of the circadian system. The kernel
structure unbiasedly reveals four interlocked negative feedback loops
contributing to circadian rhythms, and three feedback loops among them drive
the autonomous oscillation itself. Strikingly, the kernel structure, as well as
the whole clock circuitry, is overwhelmingly composed of inhibitory, rather
than activating, interactions between genes. We found that this tendency
underlies plant circadian molecular profiles which often exhibit
sharply-shaped, cuspidate waveforms. Through the generation of these cuspidate
profiles, inhibitory interactions may facilitate the global coordination of
temporally-distant clock events that are markedly peaked at very specific times
of day. Our systematic approach resulting in experimentally-testable
predictions provides insights into a design principle of biological clockwork,
with implications for synthetic biology.Comment: Supplementary material is available at the journal websit
Perspectives and Integration in SOLAS Science
Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm.
Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of oceanâatmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency.
The exchange of energy, gases and particles across the air-sea interface is controlled by a variety of biological, chemical and physical processes that operate across broad spatial and temporal scales. These processes influence the composition, biogeochemical and chemical properties of both the oceanic and atmospheric boundary layers and ultimately shape the Earth system response to climate and environmental change, as detailed in the previous four chapters. In this cross-cutting chapter we present some of the SOLAS achievements over the last decade in terms of integration, upscaling observational information from process-oriented studies and expeditionary research with key tools such as remote sensing and modelling.
Here we do not pretend to encompass the entire legacy of SOLAS efforts but rather offer a selective view of some of the major integrative SOLAS studies that combined available pieces of the immense jigsaw puzzle. These include, for instance, COST efforts to build up global climatologies of SOLAS relevant parameters such as dimethyl sulphide, interconnection between volcanic ash and ecosystem response in the eastern subarctic North Pacific, optimal strategy to derive basin-scale CO2 uptake with good precision, or significant reduction of the uncertainties in sea-salt aerosol source functions. Predicting the future trajectory of Earthâs climate and habitability is the main task ahead. Some possible routes for the SOLAS scientific community to reach this overarching goal conclude the chapter