Plant meristems carry pools of continuously active stem cells, whose activity is controlled by developmental and environmental signals. After stem cell division, daughter cells that exit the stem cell domain acquire transit amplifying cell identity before they are incorporated into organs and differentiate. In this study, we used an integrated approach to elucidate the role of HECATE (HEC) genes in regulating developmental trajectories of shoot stem cells in Arabidopsis thaliana. Our work reveals that HEC function stabilizes cell fate in distinct zones of the shoot meristem thereby controlling the spatio-temporal dynamics of stem cell differentiation. Importantly, this activity is concomitant with the local modulation of cellular responses to cytokinin and auxin, two key phytohormones regulating cell behaviour. Mechanistically, we show that HEC factors directly modulate auxin signal transduction by physical interaction with MONOPTEROS (MP), a key regulator of auxin signalling, and thus interfere with the autocatalytic stabilization of auxin signalling. Overall design: p16:HEC1-linker-GR;inflorescence meristems; 14hours; mock1,mock2,mock3,dex1,dex2,dex3
Control of plant cell fate transitions by transcriptional and hormonal signals.
Age, Specimen part, Subject
View SamplesIn the yeast Saccharomyces cerevisiae, cleavage factor I (CFI) and cleavage and polyadenylation factor (CPF) build the core of the transcription termination machinery. CFI comprises the Rna14, Rna15, Pcf11, and Clp1 proteins, as well as the associated Hrp5 RNA-binding protein. We found that CFI participates in the DNA damage response and that rna14-1 shows synthetic growth defects with mutants of different repair pathways, including homologous recombination, non-homologous end joining, post replicative repair, mismatch repair, and nucleotide excision repair, implicating that impaired RNAPII termination and 3-end processing decreases the cellular tolerance for DNA damage. Beyond replication progression defects, we found that bypass of the G1/S checkpoint in rna14-1 cells leads to synthetic sickness, accumulation of phosphorylated H2A, as well as increase in Rad52-foci and in recombination. Our data provide evidence that CFI dysfunction impairs RNAPII turnover, leading to replication hindrance and lower tolerance to exogenous DNA damage. These findings underscore the importance of coordination between transcription termination, DNA repair and replication in the maintenance of genomic stability.
Cleavage factor I links transcription termination to DNA damage response and genome integrity maintenance in Saccharomyces cerevisiae.
No sample metadata fields
View Samplesthe nuclear pore complex (NPC) is emerging as an important mediator of cellular processes beyond molecule transport, including control of gene expression, replication and DNA repair.
The Nup84 complex coordinates the DNA damage response to warrant genome integrity.
No sample metadata fields
View SamplesTHO/TREX is a conserved nuclear complex that functions in mRNP biogenesis at the interface of transcription-RNA export with a key role in preventing transcription-associated genome instability.
Genome-wide function of THO/TREX in active genes prevents R-loop-dependent replication obstacles.
No sample metadata fields
View SamplesPGC-1 transcription factor was customized to limit its interations to ERRalpha. This mutant (2x9) was used to dissect the transcription activation patterns that are attributable to the PGC1-ERR interaction and PGC-1 actions that are independent of ERR. Inactive mutant with the deleted LLXXL motifs (L2L3) and wt PGC-1 were used as negative and positive controls respectively. BGAL-expressing construct was used to control for non-specific effects of adenoviral infection.
Receptor-selective coactivators as tools to define the biology of specific receptor-coactivator pairs.
No sample metadata fields
View SamplesWe sequenced polyA mRNA from OVCAR8-ADR-Cas9 cells in which one or two of 3 epigenetic regulators (BRD4, KDM4C, KDM6B) had been knocked out to examine how global gene expression was affected and evaluate potential synergistic effects at a molecular level. Overall design: Gene expression data (RNA-Seq) in OVCAR8-ADR-Cas9 cells infected with control vector or vectors expressing gRNAs targeting one of 4 epigenetic regulators (BRD4, KDM4C, KDM6B) with biological replicates.
Multiplexed barcoded CRISPR-Cas9 screening enabled by CombiGEM.
No sample metadata fields
View SamplesWe previously identified multipotent stem cells within the lamina propria of the human olfactory mucosa, located in the nasal cavity. We also demonstrated that this cell type differentiates into neural cells and improves locomotor behavior after transplantation in a rat model of Parkinsons disease. Yet, next to nothing is known about their specific stemness characteristics. We therefore devised a study aiming to compare olfactory lamina propria stem cells from 4 individuals to bone marrow mesenchymal stem cells from 4 age- and gendermatched individuals. Using pangenomic microarrays and immunostaining with 34 cell surface marker antibodies, we show here that olfactory stem cells are closely related to bone marrow stem cells. However, olfactory stem cells exhibit also singular traits. By means of techniques such as proliferation assay, cDNA microarrays, RT-PCR, in vitro and in vivo differentiation, we report that, when compared to bone marrow stem cells, olfactory stem cells display i) a high proliferation rate; ii) a propensity to differentiate into osseous cells and iii) a disinclination to give rise to chondrocytes and adipocytes. Since peripheral olfactory stem cells originate from a neural crest-derived tissue and, as shown here, exhibit an increased expression of neural cellrelated genes, we propose to name them olfactory ecto-mesenchymal stem cells (OE-MSC). Further studies are now required to corroborate the therapeutic potential of OE-MSCs in animal models of bone and brain diseases.
The human nose harbors a niche of olfactory ectomesenchymal stem cells displaying neurogenic and osteogenic properties.
Sex, Age, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Strain-specific activation of the NF-kappaB pathway by GRA15, a novel Toxoplasma gondii dense granule protein.
Specimen part
View SamplesToxoplasma strains have been shown to modulate host cell transcription. We have found a type II Toxoplasma gene, GRA15, which activates the nuclear translocation of the NF-kappaB p65 transcription factor.
Strain-specific activation of the NF-kappaB pathway by GRA15, a novel Toxoplasma gondii dense granule protein.
Specimen part
View SamplesToxoplasma strains have been shown to modulate host cell transcription. We have found a type II Toxoplasma gene, GRA15, which activates the nuclear translocation of the NF-kappaB p65 transcription factor.
Strain-specific activation of the NF-kappaB pathway by GRA15, a novel Toxoplasma gondii dense granule protein.
Specimen part
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