scholarly journals Arabidopsis sepals: A model system for the emergent process of morphogenesis

2021 ◽  
Vol 2 ◽  
Author(s):  
Adrienne H. K. Roeder
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Cell Division ◽  
Slow Growth ◽  
Expression Patterns ◽  
Giant Cells ◽  
Model System ◽  
Gene Expression Patterns ◽  
Emergent Properties ◽  
Correct Size

Abstract During development, Arabidopsis thaliana sepal primordium cells grow, divide and interact with their neighbours, giving rise to a sepal with the correct size, shape and form. Arabidopsis sepals have proven to be a good system for elucidating the emergent processes driving morphogenesis due to their simplicity, their accessibility for imaging and manipulation, and their reproducible development. Sepals undergo a basipetal gradient of growth, with cessation of cell division, slow growth and maturation starting at the tip of the sepal and progressing to the base. In this review, I discuss five recent examples of processes during sepal morphogenesis that yield emergent properties: robust size, tapered tip shape, laminar shape, scattered giant cells and complex gene expression patterns. In each case, experiments examining the dynamics of sepal development led to the hypotheses of local rules. In each example, a computational model was used to demonstrate that these local rules are sufficient to give rise to the emergent properties of morphogenesis.

scholarly journals Recapitulation of Transcriptomic Characteristics of Primary Breast Tumours in Patient-Derived 3D Cultures in Vitro

2021 ◽  
Vol 75 (1) ◽  
pp. 20-24
Author(s):  
Dina Nitiša ◽  
Nityanand Jain ◽  
Arvīds Irmejs ◽  
Valdis Pirsko ◽  
Inese Čakstiņa
Keyword(s):  
Gene Expression ◽  
Quantitative Polymerase Chain Reaction ◽  
Expression Patterns ◽  
3D Cell Culture ◽  
Model System ◽  
Gene Expression Patterns ◽  
3D Cultures ◽  
Culture Development

AbstractBreast cancer (BC) is the most common cause of cancer-related deaths among women in Europe and worldwide. Adherent (2D) cell cultures have been the routine in vitro model system employed in preclinical BC research for the last half-century. Over the past decade, new protocols have been developed allowing patient-derived three-dimensional organoid (3D) cell culture development from a range of solid tumours, including BC. These 3D models offer a promise of closer resemblance to the native tumour than the 2D cultures. To test the assumption that an in vitro 3D BC model system provides increased faithfulness to the molecular processes happening in vivo, as compared to 2D BC cultures, post-operational material from three BC patients was used to simultaneously develop 2D and 3D cultures in vitro. When analysed by quantitative polymerase chain reaction (PCR), the gene expression patterns of the cells from 3D cultures resembled the original tissues, while the gene expression patterns of the conventional 2D cultures were more distant.

scholarly journals Adaptive divergence in transcriptome response to heat and acclimation in Arabidopsis thaliana plants from contrasting climates.

2016 ◽  
Author(s):  
Nana Zhang ◽  
Elizabeth Vierling ◽  
Stephen Tonsor
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
High Temperature ◽  
Expression Patterns ◽  
High Elevation ◽  
Adaptive Divergence ◽  
Gene Expression Patterns ◽  
Direct Exposure ◽  
Small Hsps

Phenotypic variation in stress response has been widely observed within species. This variation is an adaptive response to local climates and is controlled by gene sequence variation and especially by variation in expression at the transcriptome level. Plants from contrasting climates are thus expected to have different patterns in gene expression. Acclimation, a pre-exposure to sub-lethal temperature before exposing to extreme high temperature, is an important adaptive mechanism of plant survival. We are interested to evaluate the gene expression difference to heat stress for plants from contrasting climates and the role of acclimation in altering their gene expression pattern. Natural Arabidopsis thaliana plants from low elevation mediterranean and high elevation montane climates were exposed to two heat treatments at the bolting stage: a) 45 oC: a direct exposure to 45oC heat; b) 38/45 oC: an exposure to 45oC heat after a 38oC acclimation treatment. Variation in overall gene expression patterns was investigated. We also explored gene expression patterns for Hsp/Hsf pathway and reactive oxygen species (ROS) pathway. In both heat treatments, high elevation plants had more differentially expressed (DE) genes than low elevation plants. In 45 oC, only Hsp/Hsf pathway was activated in low elevation plants; both Hsp/Hsf and ROS pathways were activated in high elevation plants. Small Hsps had the highest magnitude of change in low elevation plants while Hsp70 and Hsp90 showed the largest magnitude of fold in high elevation plants. In 38/45 oC, Hsp/Hsf and ROS pathways were activated in both low and high elevation plants. Low elevation plants showed up-regulation in all Hsps, especially small Hsps; high elevation plants showed down-regulation in all Hsps. Low elevation and high elevation also adopted different genes in the ROS pathway. We also observed genes that shifted expression in both low and high elevation plants but with opposite directions of change. This study indicates that low and high elevation plants have evolved adaptive divergence in heat stress response. The contrasting patterns of temperature variation in low and high elevation sites appears to have played a strong role in the evolution of divergent patterns to high temperature stress, both pre-acclimation and direct exposure gene expression responses.

scholarly journals Slow Growth Induces Heat-Shock Resistance in Normal and Respiratory-deficient Yeast

2009 ◽  
Vol 20 (3) ◽  
pp. 891-903 ◽  
Author(s):  
Charles Lu ◽  
Matthew J. Brauer ◽  
David Botstein
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Growth Rates ◽  
Respiratory Activity ◽  
Slow Growth ◽  
Expression Patterns ◽  
Cross Protection ◽  
Gene Expression Patterns ◽  
Wild Type ◽  
Respiratory Deficient

Yeast cells respond to a variety of environmental stresses, including heat shock and growth limitation. There is considerable overlap in these responses both from the point of view of gene expression patterns and cross-protection for survival. We performed experiments in which cells growing at different steady-state growth rates in chemostats were subjected to a short heat pulse. Gene expression patterns allowed us to partition genes whose expression responds to heat shock into subsets of genes that also respond to slow growth rate and those that do not. We found also that the degree of induction and repression of genes that respond to stress is generally weaker in respiratory deficient mutants, suggesting a role for increased respiratory activity in the apparent stress response to slow growth. Consistent with our gene expression results in wild-type cells, we found that cells growing more slowly are cross-protected for heat shock, i.e., better able to survive a lethal heat challenge. Surprisingly, however, we found no difference in cross-protection between respiratory-deficient and wild-type cells, suggesting induction of heat resistance at low growth rates is independent of respiratory activity, even though many of the changes in gene expression are not.

Gene expression patterns in blood predict future severe endpoints in community acquired pneumonia

Pneumologie ◽  
2018 ◽  
Vol 72 (S 01) ◽  
pp. S8-S9
Author(s):  
M Bauer ◽  
H Kirsten ◽  
E Grunow ◽  
P Ahnert ◽  
M Kiehntopf ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Community Acquired Pneumonia ◽  
Gene Expression Patterns
Sign in / Sign up

Export Citation Format

Share Document