scholarly journals Structural variation at the maize WUSCHEL1 locus alters stem cell organization in inflorescences

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zongliang Chen ◽  
Wei Li ◽  
Craig Gaines ◽  
Amy Buck ◽  
Mary Galli ◽  
...  
Keyword(s):  
Stem Cell ◽  
Structural Variation ◽  
Phenotypic Variability ◽  
Response Regulators ◽  
Cytokinin Signaling ◽  
Crop Species ◽  
Developmental Program ◽  
Homeobox Transcription Factor ◽  
Cell Organization ◽  
Striking Effect

AbstractStructural variation in plant genomes is a significant driver of phenotypic variability in traits important for the domestication and productivity of crop species. Among these are traits that depend on functional meristems, populations of stem cells maintained by the CLAVATA-WUSCHEL (CLV-WUS) negative feedback-loop that controls the expression of the WUS homeobox transcription factor. WUS function and impact on maize development and yield remain largely unexplored. Here we show that the maize dominant Barren inflorescence3 (Bif3) mutant harbors a tandem duplicated copy of the ZmWUS1 gene, ZmWUS1-B, whose novel promoter enhances transcription in a ring-like pattern. Overexpression of ZmWUS1-B is due to multimerized binding sites for type-B RESPONSE REGULATORs (RRs), key transcription factors in cytokinin signaling. Hypersensitivity to cytokinin causes stem cell overproliferation and major rearrangements of Bif3 inflorescence meristems, leading to the formation of ball-shaped ears and severely affecting productivity. These findings establish ZmWUS1 as an essential meristem size regulator in maize and highlight the striking effect of cis-regulatory variation on a key developmental program.

scholarly journals Cytokinin-CLAVATA crosstalk is an ancient mechanism regulating shoot meristem homeostasis in land plants

2021 ◽  
Author(s):  
Adrienne HK Roeder ◽  
Michael J Scanlon ◽  
Joseph Cammarata ◽  
Christopher Morales Farfan
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Flowering Plant ◽  
Shoot Meristem ◽  
Cytokinin Signaling ◽  
Cytokinin Receptor ◽  
Stem Cell Maintenance ◽  
Stem Cell Regulation ◽  
Evolutionarily Conserved ◽  
Cell Organization

Plant shoots grow from stem cells within Shoot Apical Meristems (SAMs), which produce lateral organs while maintaining the stem cell pool. In the model flowering plant Arabidopsis, the CLAVATA (CLV) pathway functions antagonistically with cytokinin signaling to control the size of the multicellular SAM via negative regulation of the stem cell organizer WUSCHEL (WUS). Although comprising just a single cell, the SAM of the model moss Physcomitrium patens (formerly Physcomitrella) performs equivalent functions during stem cell maintenance and organogenesis, despite the absence of WUS-mediated stem cell organization. Our previous work showed that the stem cell-delimiting function of the CLV pathway receptors CLAVATA1 (CLV1) and RECEPTOR-LIKE PROTEIN KINASE2 (RPK2) is conserved in the moss P. patens. Here, we use P. patens to assess whether CLV-cytokinin crosstalk is also an evolutionarily conserved feature of stem cell regulation. Genetic analyses reveal that CLV1 and RPK2 regulate SAM proliferation via separate pathways in moss. Surprisingly, cytokinin receptor mutants also form ectopic stem cells in the absence of cytokinin signaling. Through modeling, we identified regulatory network archtectures that recapitulated the stem cell phenotypes of clv1 and rpk2 mutants, cytokinin application, cytokinin receptor mutations, and higher-order combinations of these perturbations. These models predict that CLV1 and RPK2 act through separate pathways wherein CLV1 represses cytokinin-mediated stem cell initiation and RPK2 inhibits this process via a separate, cytokinin-independent pathway. Our analysis suggests that crosstalk between CLV1 and cytokinin signaling is an evolutionarily conserved feature of SAM homeostasis that preceded the role of WUS in stem cell organization.

scholarly journals A role for the fusogen eff-1 in epidermal stem cell number robustness in Caenorhabditis elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sneha L. Koneru ◽  
Fu Xiang Quah ◽  
Ritobrata Ghose ◽  
Mark Hintze ◽  
Nicola Gritti ◽  
...  
Keyword(s):  
Stem Cell ◽  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Single Molecule ◽  
Phenotypic Variability ◽  
Low Frequency ◽  
Time Lapse ◽  
Cell Number ◽  
Seam Cell ◽  
Neuronal Tissues

AbstractDevelopmental patterning in Caenorhabditis elegans is known to proceed in a highly stereotypical manner, which raises the question of how developmental robustness is achieved despite the inevitable stochastic noise. We focus here on a population of epidermal cells, the seam cells, which show stem cell-like behaviour and divide symmetrically and asymmetrically over post-embryonic development to generate epidermal and neuronal tissues. We have conducted a mutagenesis screen to identify mutants that introduce phenotypic variability in the normally invariant seam cell population. We report here that a null mutation in the fusogen eff-1 increases seam cell number variability. Using time-lapse microscopy and single molecule fluorescence hybridisation, we find that seam cell division and differentiation patterns are mostly unperturbed in eff-1 mutants, indicating that cell fusion is uncoupled from the cell differentiation programme. Nevertheless, seam cell losses due to the inappropriate differentiation of both daughter cells following division, as well as seam cell gains through symmetric divisions towards the seam cell fate were observed at low frequency. We show that these stochastic errors likely arise through accumulation of defects interrupting the continuity of the seam and changing seam cell shape, highlighting the role of tissue homeostasis in suppressing phenotypic variability during development.

scholarly journals Spermatogonial stem cell organization in felid testis as revealed by Dolichos biflorus lectin

Andrology ◽  
2016 ◽  
Vol 4 (6) ◽  
pp. 1159-1168 ◽  
Author(s):  
S. Escada-Rebelo ◽  
A. F. Silva ◽  
S. Amaral ◽  
R. S. Tavares ◽  
C. Paiva ◽  
...  
Keyword(s):  
Stem Cell ◽  
Spermatogonial Stem Cell ◽  
Dolichos Biflorus ◽  
Cell Organization

Abstract 5147: Trancriptional activation of the glioma stem cell marker podoplanin by the homeobox transcription factor prox1

2010 ◽  
Author(s):  
Patrice N. Love ◽  
Ravesanker Ezhilarasan ◽  
Lindsey D. Goodman ◽  
Kenneth D. Aldape ◽  
Erik P. Sulman
Keyword(s):  
Transcription Factor ◽  
Stem Cell ◽  
Stem Cell Marker ◽  
Glioma Stem Cell ◽  
Cell Marker ◽  
Homeobox Transcription Factor

scholarly journals Single-Molecule Genomic Data Delineate Patient-Specific Tumor Profiles and Cancer Stem Cell Organization

2012 ◽  
Vol 73 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Andrea Sottoriva ◽  
Inmaculada Spiteri ◽  
Darryl Shibata ◽  
Christina Curtis ◽  
Simon Tavaré
Keyword(s):  
Stem Cell ◽  
Cancer Stem Cell ◽  
Single Molecule ◽  
Genomic Data ◽  
Patient Specific ◽  
Specific Tumor ◽  
Cell Organization

scholarly journals Type-B ARABIDOPSIS RESPONSE REGULATORs Specify the Shoot Stem Cell Niche by Dual Regulation of WUSCHEL

2017 ◽  
Vol 29 (6) ◽  
pp. 1357-1372 ◽  
Author(s):  
Wen Jing Meng ◽  
Zhi Juan Cheng ◽  
Ya Lin Sang ◽  
Miao Miao Zhang ◽  
Xiao Fei Rong ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Niche ◽  
Type B ◽  
Response Regulators ◽  
Cell Niche

scholarly journals DEG9, a serine protease, modulates cytokinin and light signaling by regulating the level of ARABIDOPSIS RESPONSE REGULATOR 4

2016 ◽  
Vol 113 (25) ◽  
pp. E3568-E3576 ◽  
Author(s):  
Wei Chi ◽  
Jing Li ◽  
Baoye He ◽  
Xin Chai ◽  
Xiumei Xu ◽  
...  
Keyword(s):  
Serine Protease ◽  
Response Regulator ◽  
Light Signaling ◽  
Plant Signaling ◽  
Response Regulators ◽  
Cytokinin Signaling ◽  
Periplasmic Proteins ◽  
The Stability ◽  
Protease Degradation ◽  
Signaling Components

Cytokinin is an essential phytohormone that controls various biological processes in plants. A number of response regulators are known to be important for cytokinin signal transduction. ARABIDOPSIS RESPONSE REGULATOR 4 (ARR4) mediates the cross-talk between light and cytokinin signaling through modulation of the activity of phytochrome B. However, the mechanism that regulates the activity and stability of ARR4 is unknown. Here we identify an ATP-independent serine protease, degradation of periplasmic proteins 9 (DEG9), which localizes to the nucleus and regulates the stability of ARR4. Biochemical evidence shows that DEG9 interacts with ARR4, thereby targeting ARR4 for degradation, which suggests that DEG9 regulates the stability of ARR4. Moreover, genetic evidence shows that DEG9 acts upstream of ARR4 and regulates the activity of ARR4 in cytokinin and light-signaling pathways. This study thus identifies a role for a ubiquitin-independent selective protein proteolysis in the regulation of the stability of plant signaling components.

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