Cell–cell interactions during patterning of the Arabidopsis anther

2010 ◽  
Vol 38 (2) ◽  
pp. 571-576 ◽  
Author(s):  
Xiaoqi Feng ◽  
Hugh G. Dickinson

Key steps in the evolution of the angiosperm anther include the patterning of the concentrically organized microsporangium and the incorporation of four such microsporangia into a leaf-like structure. Mutant studies in the model plant Arabidopsis thaliana are leading to an increasingly accurate picture of (i) the cell lineages culminating in the different cell types present in the microsporangium (the microsporocytes, the tapetum, and the middle and endothecial layers), and (ii) some of the genes responsible for specifying their fates. However, the processes that confer polarity on the developing anther and position the microsporangia within it remain unclear. Certainly, data from a range of experimental strategies suggest that hormones play a central role in establishing polarity and the patterning of the anther initial, and may be responsible for locating the microsporangia. But the fact that microsporangia were originally positioned externally suggests that their development is likely to be autonomous, perhaps with the reproductive cells generating signals controlling the growth and division of the investing anther epidermis. These possibilities are discussed in the context of the expression of genes which initiate and maintain male and female reproductive development, and in the perspective of our current views of anther evolution.

Author(s):  
Artem Minin ◽  
Igor Blatov ◽  
Valeria Lebedeva ◽  
Maxim Tuchai ◽  
Varvara Pozdina ◽  
...  

In vitro systems serve as compact and manipulate models to investigate interactions between different cell types. A homogeneous population of cells predictably and uniformly responds to external factors. In a heterogeneous cell population, the effect of external growth factors is perceived in the context of intercellular interactions. Indirect cell co-cultivation allows one to observe the paracrine effects of cells and separately analyze cell populations. The article describes an application of custom-made cell co-cultivation systems based on protein membranes separated from the bottom of the vessel by the 3d printed holder or kept afloat by a magnetic field. Using the proposed co-cultivation system, we analyzed the interaction of A549 cells and fibroblasts, in the presence and absence of growth factors. During co-cultivation of cells, the expression of genes of the activation for epithelial and mesenchymal transitions decreases. The article proposes the application of a newly available system for the co-cultivation of different cell types.


2019 ◽  
Author(s):  
Mikhail Pomaznoy ◽  
Brendan Ha ◽  
Bjoern Peters

AbstractAnalysis of transcriptomic data derived from blood samples is complicated by the complex mixture of cell types such samples contain. Transcriptomic signatures derived from such samples are often driven by a particular cell lineage within the mixture. Identifying this most contributing lineage can help to provide a biological interpretation of the signature. We created a web application CellTypeScore which quantifies and visually represents the expression level of signature genes in common blood cell types. This is done by constructing an interactive stacked bar plot with the bars representing expression of genes across blood cell types. Summed scores serve as a measure of how highly the combined signature is expressed in different cell types. An online version of the application can be found at https://tools.dice-database.org/celltypescore/.


2015 ◽  
Vol 6 (2) ◽  
pp. 96-108
Author(s):  
Elena Aleksandrovna Dementeva ◽  
Olga Petrovna Gurina

The key immunology problem remains the understanding of the mechanisms for the effective protection of the body against various pathogens with simultaneous suppression of the immune response to autoantigens. The pathogenesis of neoplastic pathological processes includes violations of the mechanisms of normal cell growth and cell proliferation. Antitumor immune response is a complex event, involving many different cell types. But despite the ability of the immune system to recognize and respond to a variety of tumor-associated antigens, the neoplastic process overcomes the protective forces of the organism, grows and spreads. For cancer cells characterized by independence from antiproliferative signals, autocrine stimulation of growth disturbances in the system, induction of apoptosis and control of genome stability. As a result of accumulation of genetic and epigenetic changes in tumor cells differ significantly from the normal range and the level of expression of genes involved in the transformation process, the accumulation of mutations in key genes promoters and suppressors of tumorigenesis. This creates the opportunity for recognition by cells of the immune system. The study of changes in value and operation of the various elements of the immune system in the development of experimental neoplastic process allows you to identify the mechanisms of interaction in the system «malignant tumor-immune system, to assess patterns of interaction with other organs and tissues, to create a theoretical pathogenetically reasonable premise for the development of anticancer therapy.


2015 ◽  
Author(s):  
Hajk-Georg Drost ◽  
Julia Bellstaedt ◽  
Diarmuid O'Maoileidigh ◽  
Anderson Silva ◽  
Alexander Gabel ◽  
...  

The historic developmental hourglass concept depicts the convergence of animal embryos to a common form during the phylotypic period. Recently, it has been shown that a transcriptomic hourglass is associated with this morphological pattern, consistent with the idea of underlying selective constraints due to intense molecular interactions during body plan establishment. Although plants do not exhibit a morphological hourglass during embryogenesis, a transcriptomic hourglass has nevertheless been identified in the model plant Arabidopsis thaliana. Here, we investigated whether plant hourglass patterns are also found post-embryonically. We found that the two main phase changes during the life cycle of Arabidopsis, from embryonic to vegetative and from vegetative to reproductive development, are associated with transcriptomic hourglass patterns. In contrast, flower development, a process dominated by organ formation, is not. This suggests that plant hourglass patterns are decoupled from organogenesis and body plan establishment. Instead, they may reflect general transitions through organizational checkpoints.


2019 ◽  
Vol 63 (11-12) ◽  
pp. 615-621 ◽  
Author(s):  
Rafal P. Piprek ◽  
Dagmara Podkowa ◽  
Malgorzata Kloc ◽  
Jacek Z. Kubiak

Mechanisms governing differentiation of the bipotential gonad into the testes or ovaries are complex and still vague. The primary cilium is an organelle involved in cell signaling, which controls the development of many organs, but the role of primary cilium in the sex determination and sexual differentiation of gonads is com-pletely unknown. Here we studied the expression of genes involved in primary cilium formation and function-ing in fetal mouse gonads, before, during and after sexual differentiation. We studied the expression of 175 primary cilia-related genes using microarray technique. 144 of these genes were ubiquitously expressed in all studied cell types with no significant differences in expression level. Such a high level of expression of primary cilia-related genes in developing mouse gonads suggests that the primary cilia and/or primary cilia-related genes are important for the development of both somatic and germline component of the gonads. Only 31 genes showed a difference in expression between different cell types, which suggests that they have different functions in the somatic and germ cells. These results justify further studies on the role of primary cilia and the primary cilia-related genes in gonad development.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254024
Author(s):  
Sanjeeva Metikala ◽  
Satish Casie Chetty ◽  
Saulius Sumanas

During embryonic development, cells differentiate into a variety of distinct cell types and subtypes with diverse transcriptional profiles. To date, transcriptomic signatures of different cell lineages that arise during development have been only partially characterized. Here we used single-cell RNA-seq to perform transcriptomic analysis of over 20,000 cells disaggregated from the trunk region of zebrafish embryos at the 30 hpf stage. Transcriptional signatures of 27 different cell types and subtypes were identified and annotated during this analysis. This dataset will be a useful resource for many researchers in the fields of developmental and cellular biology and facilitate the understanding of molecular mechanisms that regulate cell lineage choices during development.


2003 ◽  
Vol 198 (9) ◽  
pp. 1391-1402 ◽  
Author(s):  
Tiziana Schioppa ◽  
Badarch Uranchimeg ◽  
Alessandra Saccani ◽  
Subhra K. Biswas ◽  
Andrea Doni ◽  
...  

Cell adaptation to hypoxia (Hyp) requires activation of transcriptional programs that coordinate expression of genes involved in oxygen delivery (via angiogenesis) and metabolic adaptation (via glycolysis). Here, we describe that oxygen availability is a determinant parameter in the setting of chemotactic responsiveness to stromal-derived factor 1 (CXCL12). Low oxygen concentration induces high expression of the CXCL12 receptor, CXC receptor 4 (CXCR4), in different cell types (monocytes, monocyte-derived macrophages, tumor-associated macrophages, endothelial cells, and cancer cells), which is paralleled by increased chemotactic responsiveness to its specific ligand. CXCR4 induction by Hyp is dependent on both activation of the Hyp-inducible factor 1 α and transcript stabilization. In a relay multistep navigation process, the Hyp–Hyp-inducible factor 1 α–CXCR4 pathway may regulate trafficking in and out of hypoxic tissue microenvironments.


2021 ◽  
Author(s):  
Sanjeeva S Metikala ◽  
Satish Casie Chetty ◽  
Saulius Sumanas

During embryonic development, cells differentiate into a variety of distinct cell types and subtypes with diverse transcriptional profiles. To date, transcriptomic signatures of different cell lineages that arise during development have been only partially characterized. Here we used single-cell RNA-seq to perform transcriptomic analysis of over 20,000 cells disaggregated from the trunk region of zebrafish embryos at the 30 hpf stage. Transcriptional signatures of 27 different cell types and subtypes were identified and annotated during this analysis. This dataset will be a useful resource for many researchers in the fields of developmental and cellular biology and facilitate the understanding of molecular mechanisms that regulate cell lineage choices during development.


Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.


1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.


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