scholarly journals Role of lamins in 3D genome organization and global gene expression

Nucleus ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Youngjo Kim ◽  
Xiaobin Zheng ◽  
Yixian Zheng
Keyword(s):  
Gene Expression ◽  
Genome Organization ◽  
Global Gene Expression ◽  
3D Genome

scholarly journals AGO1 in association with NEAT1 lncRNA contributes to nuclear and 3D chromatin architecture in human cells

2019 ◽  
Author(s):  
Muhammad Shuaib ◽  
Krishna Mohan Parsi ◽  
Hideya Kawaji ◽  
Manjula Thimma ◽  
Sabir Abdu Adroub ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genome Organization ◽  
Global Gene Expression ◽  
Human Cells ◽  
Nuclear Bodies ◽  
Genome Architecture ◽  
Global Changes ◽  
Active Chromatin ◽  
Altered Expression ◽  
3D Genome

AbstractAside from their roles in the cytoplasm, RNA-interference components have been reported to localize also in the nucleus of human cells. In particular, AGO1 associates with active chromatin and appears to influence global gene expression. However, the mechanistic aspects remain elusive. Here, we identify AGO1 as a paraspeckle component that in combination with the NEAT1 lncRNA maintains 3D genome architecture. We demonstrate that AGO1 interacts with NEAT1 lncRNA and its depletion affects NEAT1 expression and the formation of paraspeckles. By Hi-C analysis in AGO1 knockdown cells, we observed global changes in chromatin organization, including TADs configuration, and A/B compartment mixing. Consistently, distinct groups of genes located within the differential interacting loci showed altered expression upon AGO1 depletion. NEAT1 knockout cells displayed similar changes in TADs and higher-order A/B compartmentalization. We propose that AGO1 in association with NEAT1 lncRNA can act as a scaffold that bridges chromatin and nuclear bodies to regulate genome organization and gene expression in human cells.

scholarly journals Low ribosomal RNA genes copy number provoke genomic instability and chromosomal segment duplication events that modify global gene expression and plant-pathogen response

2020 ◽  
Author(s):  
Ariadna Picart-Picolo ◽  
Stefan Grob ◽  
Nathalie Picault ◽  
Michal Franek ◽  
Thierry halter ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genomic Instability ◽  
Ribosomal Rna ◽  
Plant Pathogen ◽  
Genome Organization ◽  
Global Gene Expression ◽  
Rrna Gene ◽  
3D Genome ◽  
Gene Copies ◽  
Pathogen Response

ABSTRACTAmong the hundreds of ribosomal RNA (rRNA) gene copies organized as tandem repeats in the nucleolus organizer regions (NORs), only a portion is usually actively expressed in the nucleolus and participate in the ribosome biogenesis process. The role of these extra-copies remains elusive, but previous studies suggested their importance in genome stability and global gene expression. Because the nucleolus is also a platform for nuclear organization, we tested the impact of a decreased amount of rRNA gene copies on the Arabidopsis thaliana 3D genome organization and stability, using an A. thaliana line only containing 20% of rRNA gene copies (20rDNA line). Compared to the wild-type Col-0, the 20rDNA line shows several signs of genomic instability, such as variations in 3D genome organization, spontaneous double-strand breaks accumulation, transcriptomic changes, and higher DNA methylation level. Strikingly, using genomic and microscopic approaches, we identified seven large tandem duplications in direct orientation (TDDOs) ranging from 60 kb to 1.44 Mb. As a consequence, more than 600 genes were duplicated, often associated with an increase in their expression level. Among them, we found several upregulated genes involved in plant-pathogen response, which could explain why the 20rDNA line is hyper-resistant to both bacterial and nematode infections. Finally, we show that the TDDOs create gene fusions and/or truncations and we discuss their potential implications on plant genome evolution.

scholarly journals Multiple Known Mechanisms and a Possible Role of an Enhanced Immune System in Bt-Resistance in a Field Population of the Bollworm, Helicoverpa zea: Differences in Gene Expression with RNAseq

2020 ◽  
Vol 21 (18) ◽  
pp. 6528
Author(s):  
Roger D. Lawrie ◽  
Robert D. Mitchell III ◽  
Jean Marcel Deguenon ◽  
Loganathan Ponnusamy ◽  
Dominic Reisig ◽  
...  
Keyword(s):  
Gene Expression ◽  
Serine Proteases ◽  
Helicoverpa Zea ◽  
Insect Pests ◽  
Global Gene Expression ◽  
Field Resistance ◽  
Bt Resistance ◽  
Imd Pathway ◽  
Immune Pathway

Several different agricultural insect pests have developed field resistance to Bt (Bacillus thuringiensis) proteins (ex. Cry1Ac, Cry1F, etc.) expressed in crops, including corn and cotton. In the bollworm, Helicoverpa zea, resistance levels are increasing; recent reports in 2019 show up to 1000-fold levels of resistance to Cry1Ac, a major insecticidal protein in Bt-crops. A common method to analyze global differences in gene expression is RNA-seq. This technique was used to measure differences in global gene expression between a Bt-susceptible and Bt-resistant strain of the bollworm, where the differences in susceptibility to Cry1Ac insecticidal proteins were 100-fold. We found expected gene expression differences based on our current understanding of the Bt mode of action, including increased expression of proteases (trypsins and serine proteases) and reduced expression of Bt-interacting receptors (aminopeptidases and cadherins) in resistant bollworms. We also found additional expression differences for transcripts that were not previously investigated, i.e., transcripts from three immune pathways-Jak/STAT, Toll, and IMD. Immune pathway receptors (ex. PGRPs) and the IMD pathway demonstrated the highest differences in expression. Our analysis suggested that multiple mechanisms are involved in the development of Bt-resistance, including potentially unrecognized pathways.

scholarly journals Impact of Chromosome Fusions on 3D Genome Organization and Gene Expression in Budding Yeast

Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 651-667 ◽  
Author(s):  
Marco Di Stefano ◽  
Francesca Di Giovanni ◽  
Vasilisa Pozharskaia ◽  
Mercè Gomar-Alba ◽  
Davide Baù ◽  
...  
Keyword(s):  
Gene Expression ◽  
Budding Yeast ◽  
Nuclear Organization ◽  
Nuclear Periphery ◽  
Three Dimensional ◽  
Global Gene Expression ◽  
3D Genome ◽  
Expression Of Genes ◽  
Genome Wide ◽  
Chromosome Fusions

The three-dimensional (3D) organization of chromosomes can influence transcription. However, the frequency and magnitude of these effects remain debated. To determine how changes in chromosome positioning affect transcription across thousands of genes with minimal perturbation, we characterized nuclear organization and global gene expression in budding yeast containing chromosome fusions. We used computational modeling and single-cell imaging to determine chromosome positions, and integrated these data with genome-wide transcriptional profiles from RNA sequencing. We find that chromosome fusions dramatically alter 3D nuclear organization without leading to strong genome-wide changes in transcription. However, we observe a mild but significant and reproducible increase in the expression of genes displaced away from the periphery. The increase in transcription is inversely proportional to the propensity of a given locus to be at the nuclear periphery; for example, a 10% decrease in the propensity of a gene to reside at the nuclear envelope is accompanied by a 10% increase in gene expression. Modeling suggests that this is due to both deletion of telomeres and to displacement of genes relative to the nuclear periphery. These data suggest that basal transcriptional activity is sensitive to radial changes in gene position, and provide insight into the functional relevance of budding yeast chromosome-level 3D organization in gene expression.

The role of the Shigella flexneri yihE gene in LPS synthesis and virulence

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 1079-1084 ◽  
Author(s):  
Bryn Edwards-Jones ◽  
Paul R. Langford ◽  
J. Simon Kroll ◽  
Jun Yu
Keyword(s):  
Gene Expression ◽  
Global Change ◽  
Unknown Function ◽  
Guinea Pigs ◽  
Antimicrobial Agents ◽  
Shigella Flexneri ◽  
Global Gene Expression ◽  
Wild Type ◽  
In Trans

Previously, the authors have shown that inactivation of Shigella flexneri yihE, a gene of unknown function upstream of dsbA, which encodes a periplasmic disulphide catalyst, results in a global change of gene expression. Among the severely down-regulated genes are galETKM, suggesting that the yihE mutant, Sh54, may inefficiently produce the UDP-glucose and UDP-galactose required for LPS synthesis. This paper demonstrates that LPS synthesis in Sh54 is impaired. As a result, Sh54 is unable to polymerize host cell actin, due to aberrant localization of IcsA, or to cause keratoconjunctivitis in guinea pigs. Furthermore, Sh54 is more sensitive to some antimicrobial agents, and exhibits epithelial cytotoxicity characteristic of neither wild-type nor dsbA mutants. Supplying galETK in trans restores LPS synthesis and corrects all the defects. Hence, it is clear that the Shigella yihE gene is important not only in regulating global gene expression, as shown previously, but also in virulence through LPS synthesis via regulating the expression of the galETK operon.

Transcriptomes reveal alterations in gravity impact circadian clocks and activate mechanotransduction pathways with adaptation through epigenetic change

2015 ◽  
Vol 47 (4) ◽  
pp. 113-128 ◽  
Author(s):  
Theresa Casey ◽  
Osman V. Patel ◽  
Karen Plaut
Keyword(s):  
Gene Expression ◽  
Late Pregnancy ◽  
Global Gene Expression ◽  
Circadian Clocks ◽  
Epigenetic Change ◽  
Pregnant Rats ◽  
Affymetrix Genechips ◽  
Expression Of Genes ◽  
The Impact

Few studies have investigated the impact of alterations in gravity on mammalian transcriptomes. Here, we describe the impact of spaceflight on mammary transcriptome of late pregnant rats and the effect of hypergravity exposure on mammary, liver, and adipose transcriptomes in late pregnancy and at the onset of lactation. RNA was isolated from mammary collected on pregnancy day 20 from rats exposed to spaceflight from days 11 to 20 of gestation. To measure the impact of hypergravity on mammary, liver, and adipose transcriptomes we isolated RNA from tissues collected on P20 and lactation day 1 from rats exposed to hypergravity beginning on pregnancy day 9. Gene expression was measured with Affymetrix GeneChips. Microarray analysis of variance revealed alterations in gravity affected the expression of genes that regulate circadian clocks and activate mechanotransduction pathways. Changes in these systems may explain global gene expression changes in immune response, metabolism, and cell proliferation. Expression of genes that modify chromatin structure and methylation was affected, suggesting adaptation to gravity alterations may proceed through epigenetic change. Altered gravity experiments offer insights into the role of forces omnipresent on Earth that shape genomes in heritable ways. Our study is the first to analyze the impact of alterations in gravity on transcriptomes of pregnant and lactating mammals. Findings provide insight into systems that sense gravity and the way in which they affect phenotype, as well as the possibility of sustaining life beyond Earth's orbit.

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