scholarly journals Does Shoot Apical Meristem Function as the Germline in Safeguarding Against Excess of Mutations?

2021 ◽  
Vol 12 ◽  
Author(s):  
Agata Burian
Keyword(s):  
Cell Fate ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Cell Lineage ◽  
Temporal Distribution ◽  
Tissue Level ◽  
Protective Mechanisms ◽  
Genetic Continuity ◽  
Spatio Temporal ◽  
Living Organisms

A genetic continuity of living organisms relies on the germline which is a specialized cell lineage producing gametes. Essential in the germline functioning is the protection of genetic information that is subjected to spontaneous mutations. Due to indeterminate growth, late specification of the germline, and unique longevity, plants are expected to accumulate somatic mutations during their lifetime that leads to decrease in individual and population fitness. However, protective mechanisms, similar to those in animals, exist in plant shoot apical meristem (SAM) allowing plants to reduce the accumulation and transmission of mutations. This review describes cellular- and tissue-level mechanisms related to spatio-temporal distribution of cell divisions, organization of stem cell lineages, and cell fate specification to argue that the SAM functions analogous to animal germline.

scholarly journals Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Träber ◽  
K. Uhlmann ◽  
S. Girardo ◽  
G. Kesavan ◽  
K. Wagner ◽  
...  
Keyword(s):  
Computational Analysis ◽  
Tissue Level ◽  
Quantitative Investigation ◽  
Pulsatile Pressure ◽  
Spatio Temporal ◽  
Stress Sensing ◽  
Living Organisms ◽  
Insight Into

AbstractMechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatio-temporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.

scholarly journals TGF-β signaling is critical for maintenance of the tendon cell fate

2019 ◽  
Author(s):  
Guak-Kim Tan ◽  
Brian A. Pryce ◽  
Anna Stabio ◽  
John V. Brigande ◽  
ChaoJie Wang ◽  
...  
Keyword(s):  
Cell Fate ◽  
Essential Role ◽  
Cell Lineage ◽  
Molecular Pathways ◽  
Type Ii ◽  
Critical Importance ◽  
Tgfβ Signaling ◽  
Differentiation Markers ◽  
Tendon Cell ◽  
Spatio Temporal

AbstractStudies of cell fate focus on specification, but little is known about maintenance of the differentiated state. We find that TGFβ signaling plays an essential role in maintenance of the tendon cell fate. To examine the role TGFβ signaling in tenocytes TGFβ type II receptor was targeted in the Scleraxis cell lineage. Tendon development was not disrupted in mutant embryos, but shortly after birth tenocytes lost differentiation markers and reverted to a more stem/progenitor state. Targeting of Tgfbr2 using other Cre drivers did not cause tenocyte dedifferentiation suggesting a critical significance for the spatio-temporal activity of ScxCre. Viral reintroduction of Tgfbr2 to mutants was sufficient to prevent and even rescue mutant tenocytes suggesting a continuous and cell-autonomous role for TGFβ signaling in cell fate maintenance. These results uncover the critical importance of molecular pathways that maintain the differentiated cell fate and a key role for TGFβ signaling in these processes.

Cell-lineage patterns in the shoot apical meristem of the germinating maize embryo

Planta ◽  
1988 ◽  
Vol 175 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Carl N. McDaniel ◽  
R. Scott Poethig
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Cell Lineage ◽  
Maize Embryo

scholarly journals Diversity of phyllotaxis in land plants in reference to the shoot apical meristem structure

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Edyta M. Gola ◽  
Alicja Banasiak
Keyword(s):  
Pattern Formation ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Land Plants ◽  
Phyllotactic Pattern ◽  
Lateral Organs ◽  
Spatio Temporal

Regularity and periodicity in the arrangements of organs in all groups of land plants raise questions about the mechanisms underlying phyllotactic pattern formation. The initiation of the lateral organs (leaves, flowers, etc.), and thus, their spatio-temporal positioning, occurs in the shoot apical meristem (SAM) and is related to the structure and organogenic activity of the meristem. In this review, we present some aspects of the diversity and stability of phyllotactic patterns in the major lineages of land plants, from bryophytes to angiosperms, in which SAM structures differ significantly. In addition, we discuss some of the possible mechanisms involved in the formation of the recurring arrangement of the lateral organs.

scholarly journals WUSCHEL in the shoot apical meristem: old player, new tricks

2020 ◽  
Author(s):  
Filipa Lopes ◽  
Carlos Galvan-Ampudia ◽  
Benoit Landrein
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Shoot Apical Meristem ◽  
Feedback Loop ◽  
Apical Meristem ◽  
Molecular Mechanisms ◽  
Central Zone ◽  
Environmental Signals ◽  
Plant Environment ◽  
Organizing Center

Abstract The maintenance of the stem cell niche in the shoot apical meristem, the structure that generates all of the aerial organs of the plant, relies on a canonical feedback loop between WUSCHEL (WUS) and CLV3 (CLV3). WUS is a homeodomain transcription factor expressed in the organizing center that moves to the central zone to promote stem cell fate. CLAVATA3 is a peptide whose expression is induced by WUS in the central zone that can move back to the organizing center to inhibit WUS expression. Within the last 20 years since the initial formulation of the CLV/WUS feedback loop, the mechanisms of stem cell maintenance have been intensively studied and the function of WUS has been redefined. In this review, we will highlight the most recent advances in our comprehension of the molecular mechanisms of WUS function, of its interaction with other transcription factors and with hormonal signals and of its connection to environmental signals. Through this, we will show how WUS can integrate both internal and external cues to adapt meristem function to the plant environment.

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 Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development

2018 ◽  
Author(s):  
N. Träber ◽  
K. Uhlmann ◽  
S. Girardo ◽  
G. Kesavan ◽  
K. Wagner ◽  
...  
Keyword(s):  
Computational Analysis ◽  
Tissue Level ◽  
Quantitative Investigation ◽  
Pulsatile Pressure ◽  
Spatio Temporal ◽  
Stress Sensing ◽  
Living Organisms ◽  
Insight Into

ABSTRACTMechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatiotemporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.

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