scholarly journals Temporal integration of auxin information for the regulation of patterning

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Carlos S Galvan-Ampudia ◽  
Guillaume Cerutti ◽  
Jonathan Legrand ◽  
Géraldine Brunoud ◽  
Raquel Martin-Arevalillo ◽  
...  
Keyword(s):  
Shoot Apex ◽  
Temporal Dynamics ◽  
Quantitative Imaging ◽  
Temporal Integration ◽  
Positional Information ◽  
High Definition ◽  
Auxin Concentration ◽  
Spatio Temporal ◽  
High Auxin ◽  
Multicellular Organisms

Positional information is essential for coordinating the development of multicellular organisms. In plants, positional information provided by the hormone auxin regulates rhythmic organ production at the shoot apex, but the spatio-temporal dynamics of auxin gradients is unknown. We used quantitative imaging to demonstrate that auxin carries high-definition graded information not only in space but also in time. We show that, during organogenesis, temporal patterns of auxin arise from rhythmic centrifugal waves of high auxin travelling through the tissue faster than growth. We further demonstrate that temporal integration of auxin concentration is required to trigger the auxin-dependent transcription associated with organogenesis. This provides a mechanism to temporally differentiate sites of organ initiation and exemplifies how spatio-temporal positional information can be used to create rhythmicity.

scholarly journals From spatio-temporal morphogenetic gradients to rhythmic patterning at the shoot apex

2018 ◽  
Author(s):  
Carlos S. Galvan-Ampudia ◽  
Guillaume Cerutti ◽  
Jonathan Legrand ◽  
Romain Azais ◽  
Géraldine Brunoud ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Shoot Apex ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Plant Hormone ◽  
Temporal Dynamics ◽  
Quantitative Imaging ◽  
Transport Network ◽  
High Definition ◽  
Spatio Temporal

AbstractRhythmic patterning is central to the development of eukaryotes, particularly in plant shoot post-embryonic development. The plant hormone auxin drives rhythmic patterning at the shoot apical meristem, but the spatio-temporal dynamics of the auxin gradients is unknown. We used quantitative imaging to demonstrate that auxin provides high-definition graded information not only in space but also in time. We provide evidence that developing organs are auxin-emitting centers that could self-organize spatio-temporal auxin gradients through a transport network converging on the meristem center. We further show that a memory of the exposition of cells to auxin allows to differentiate temporally sites of organ initiation, providing a remarkable example of how the dynamic redistribution of a morphogenetic regulator can be used to create rhythmicity.

scholarly journals Spatio-temporal Dynamics of the Patterning of Arabidopsis Flower Meristem

2020 ◽  
Author(s):  
José Díaz ◽  
Elena R. Álvarez-Buylla
Keyword(s):  
Flower Development ◽  
Apical Meristem ◽  
Temporal Dynamics ◽  
Positional Information ◽  
Floral Organ ◽  
Necessary Condition ◽  
Sufficient Condition ◽  
Abc Model ◽  
Flower Meristem ◽  
Spatio Temporal

AbstractThe qualitative model presented in this work recovers the onset of the four fields that correspond to those of each floral organ whorl of Arabidopsis flower, suggesting a mechanism for the generation of the positional information required for the differential expression of the A, B and C identity genes according to the ABC model for organ determination during early stages of flower development. Our model integrates a previous model for the emergence of WUS pattern in the apical meristem, and shows that this pre-pattern is a necessary but not sufficient condition for the posterior information of the four fields predicted by the ABC model. Furthermore, our model predicts that LFY diffusion along the L1 layer of cells is not a necessary condition for the patterning of the floral meristem.

scholarly journals Mesoderm patterning by a dynamic gradient of retinoic acid signalling

2020 ◽  
Vol 375 (1809) ◽  
pp. 20190556 ◽  
Author(s):  
Ségolène Bernheim ◽  
Sigolène M. Meilhac
Keyword(s):  
Retinoic Acid ◽  
Temporal Dynamics ◽  
Positional Information ◽  
Retinoic Acid Signalling ◽  
Dynamic Expression ◽  
Common Principle ◽  
Molecular Mechanism Of Action ◽  
Positive And Negative Feedback ◽  
Spatio Temporal ◽  
Mesoderm Patterning

Retinoic acid (RA), derived from vitamin A, is a major teratogen, clinically recognized in 1983. Identification of its natural presence in the embryo and dissection of its molecular mechanism of action became possible in the animal model with the advent of molecular biology, starting with the cloning of its nuclear receptor. In normal development, the dose of RA is tightly controlled to regulate organ formation. Its production depends on enzymes, which have a dynamic expression profile during embryonic development. As a small molecule, it diffuses rapidly and acts as a morphogen. Here, we review advances in deciphering how endogenously produced RA provides positional information to cells. We compare three mesodermal tissues, the limb, the somites and the heart, and discuss how RA signalling regulates antero-posterior and left–right patterning. A common principle is the establishment of its spatio-temporal dynamics by positive and negative feedback mechanisms and by antagonistic signalling by FGF. However, the response is cell-specific, pointing to the existence of cofactors and effectors, which are as yet incompletely characterized. This article is part of a discussion meeting issue ‘Contemporary morphogenesis’.

scholarly journals Spatio-Temporal Dynamics of the Patterning of Arabidopsis Flower Meristem

2021 ◽  
Vol 12 ◽  
Author(s):  
José Díaz ◽  
Elena R. Álvarez-Buylla
Keyword(s):  
Flower Development ◽  
Temporal Dynamics ◽  
Positional Information ◽  
Floral Organ ◽  
Floral Meristem ◽  
Necessary Condition ◽  
Sufficient Condition ◽  
Abc Model ◽  
Flower Meristem ◽  
Spatio Temporal

The qualitative model presented in this work recovers the onset of the four fields that correspond to those of each floral organ whorl of Arabidopsis flower, suggesting a mechanism for the generation of the positional information required for the differential expression of the A, B, and C identity genes according to the ABC model for organ determination during early stages of flower development. Our model integrates a previous model for the emergence of WUS pattern in the floral meristem, and shows that this pre-pattern is a necessary but not sufficient condition for the posterior information of the four fields predicted by the ABC model. Furthermore, our model predicts that LFY diffusion along the L1 layer of cells is not a necessary condition for the patterning of the floral meristem.

Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

2020 ◽  
Vol 637 ◽  
pp. 117-140 ◽  
Author(s):  
DW McGowan ◽  
ED Goldstein ◽  
ML Arimitsu ◽  
AL Deary ◽  
O Ormseth ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Gulf Of Alaska ◽  
Data Series ◽  
Limited Information ◽  
Important Species ◽  
Multiple Data ◽  
Spatial And Temporal Dynamics ◽  
Spawning Areas ◽  
Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

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