scholarly journals A trans-acting long non-coding RNA represses flowering in Arabidopsis

2021 ◽  
Author(s):  
Yu Jin ◽  
Maxim Ivanov ◽  
Anna Nelson Dittrich ◽  
Andrew Nelson ◽  
Sebastian Marquardt

Eukaryotic genomes give rise to thousands of long non-coding RNAs (lncRNAs), yet the purpose of lncRNAs remains largely enigmatic. Functional characterization of lncRNAs is challenging due to multiple orthogonal hypothesis for molecular activities of lncRNA loci. Here, we identified a flowering associated intergenic lncRNA (FLAIL) that represses flowering in Arabidopsis. An allelic series of flail loss-of-function mutants generated by CRISPR/Cas9 and T-DNA mutagenesis showed an early flowering phenotype. Gene expression analyses in flail mutants revealed differentially expressed genes linked to the regulation of flowering. A genomic rescue fragment of FLAIL introduced in flail mutants complemented gene expression defects and early flowering, consistent with trans-acting effects of the FLAIL RNA. Knock-down of FLAIL RNA levels using the artificial microRNA approach revealed an early flowering phenotype shared with genomic mutations, indicating a trans-acting role of FLAIL RNA in the repression of flowering time. Genome-wide detection of FLAIL-DNA interactions by ChIRP-seq suggested that FLAIL may directly bind genomic regions. FLAIL bound to genes involved in regulation of flowering that were differentially expressed in flail, consistent with the interpretation of FLAIL as a trans-acting lncRNA directly shaping gene expression. Our findings highlight FLAIL as a trans-acting lncRNA that affects flowering in Arabidopsis, likely through mediating transcriptional regulation of genes directly bound by FLAIL.

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 520
Author(s):  
Wenfeng Nie ◽  
Jinyu Wang

As essential structural components of ATP-dependent chromatin-remodeling complex, the nucleolus-localized actin-related proteins (ARPs) play critical roles in many biological processes. Among them, ARP4 is identified as an integral subunit of chromatin remodeling complex SWR1, which is conserved in yeast, humans and plants. It was shown that RNAi mediated knock-down of Arabidopsis thaliana ARP4 (AtARP4) could affect plant development, specifically, leading to early flowering. However, so far, little is known about how ARP4 functions in the SWR1 complex in plant. Here, we identified a loss-of-function mutant of AtARP4 with a single nucleotide change from glycine to arginine, which had significantly smaller leaf size. The results from the split luciferase complementation imaging (LCI) and yeast two hybrid (Y2H) assays confirmed its physical interaction with the scaffold and catalytic subunit of SWR1 complex, photoperiod-independent early flowering 1 (PIE1). Furthermore, mutation of AtARP4 caused altered transcription response of hundreds of genes, in which the number of up-regulated differentially expressed genes (DEGs) was much larger than those down-regulated. Although most DEGs in atarp4 are related to plant defense and response to hormones such as salicylic acid, overall, it has less overlapping with other swr1 mutants and the hta9 hta11 double-mutant. In conclusion, our results reveal that AtARP4 is important for plant growth and such an effect is likely attributed to its repression on gene expression, typically at defense-related loci, thus providing some evidence for the coordination of plant growth and defense, while the regulatory patterns and mechanisms are distinctive from other SWR1 complex components.


2018 ◽  
Vol 115 (47) ◽  
pp. E11081-E11090 ◽  
Author(s):  
Ryan A. York ◽  
Chinar Patil ◽  
Kawther Abdilleh ◽  
Zachary V. Johnson ◽  
Matthew A. Conte ◽  
...  

Many behaviors are associated with heritable genetic variation [Kendler and Greenspan (2006) Am J Psychiatry 163:1683–1694]. Genetic mapping has revealed genomic regions or, in a few cases, specific genes explaining part of this variation [Bendesky and Bargmann (2011) Nat Rev Gen 12:809–820]. However, the genetic basis of behavioral evolution remains unclear. Here we investigate the evolution of an innate extended phenotype, bower building, among cichlid fishes of Lake Malawi. Males build bowers of two types, pits or castles, to attract females for mating. We performed comparative genome-wide analyses of 20 bower-building species and found that these phenotypes have evolved multiple times with thousands of genetic variants strongly associated with this behavior, suggesting a polygenic architecture. Remarkably, F1 hybrids of a pit-digging and a castle-building species perform sequential construction of first a pit and then a castle bower. Analysis of brain gene expression in these hybrids showed that genes near behavior-associated variants display behavior-dependent allele-specific expression with preferential expression of the pit-digging species allele during pit digging and of the castle-building species allele during castle building. These genes are highly enriched for functions related to neurodevelopment and neural plasticity. Our results suggest that natural behaviors are associated with complex genetic architectures that alter behavior via cis-regulatory differences whose effects on gene expression are specific to the behavior itself.


Parasitology ◽  
2009 ◽  
Vol 136 (5) ◽  
pp. 469-485 ◽  
Author(s):  
A. S. TAFT ◽  
J. J. VERMEIRE ◽  
J. BERNIER ◽  
S. R. BIRKELAND ◽  
M. J. CIPRIANO ◽  
...  

SUMMARYInfection of the snail,Biomphalaria glabrata, by the free-swimming miracidial stage of the human blood fluke,Schistosoma mansoni, and its subsequent development to the parasitic sporocyst stage is critical to establishment of viable infections and continued human transmission. We performed a genome-wide expression analysis of theS. mansonimiracidia and developing sporocyst using Long Serial Analysis of Gene Expression (LongSAGE). Five cDNA libraries were constructed from miracidia andin vitrocultured 6- and 20-day-old sporocysts maintained in sporocyst medium (SM) or in SM conditioned by previous cultivation with cells of theB. glabrataembryonic (Bge) cell line. We generated 21 440 SAGE tags and mapped 13 381 to theS. mansonigene predictions (v4.0e) either by estimating theoretical 3′ UTR lengths or using existing 3′ EST sequence data. Overall, 432 transcripts were found to be differentially expressed amongst all 5 libraries. In total, 172 tags were differentially expressed between miracidia and 6-day conditioned sporocysts and 152 were differentially expressed between miracidia and 6-day unconditioned sporocysts. In addition, 53 and 45 tags, respectively, were differentially expressed in 6-day and 20-day cultured sporocysts, due to the effects of exposure to Bge cell-conditioned medium.


2022 ◽  
Vol 12 ◽  
Author(s):  
Beatrice E. Gee ◽  
Andrea Pearson ◽  
Iris Buchanan-Perry ◽  
Roger P. Simon ◽  
David R. Archer ◽  
...  

Whole transcriptome RNA-sequencing was performed to quantify RNA expression changes in whole blood samples collected from steady state sickle cell anemia (SCA) and control subjects. Pediatric SCA and control subjects were recruited from Atlanta (GA)—based hospital(s) systems and consented for RNA sequencing. RNA sequencing was performed on an Ion Torrent S5 sequencer, using the Ion Total RNA-seq v2 protocol. Data were aligned to the hg19 reference genome and analyzed in the Partek Genomics studio package (v7.0). 223 genes were differentially expressed between SCA and controls (± 1.5 fold change FDR p < 0.001) and 441 genes show differential transcript expression (± 1.5 fold FDR p < 0.001). Differentially expressed RNA are enriched for hemoglobin associated genes and ubiquitin-proteasome pathway genes. Further analysis shows higher gamma globin gene expression in SCA (33-fold HBG1 and 49-fold HBG2, both FDR p < 0.05), which did not correlate with hemoglobin F protein levels. eQTL analysis identified SNPs in novel non-coding RNA RYR2 gene as having a potential regulatory role in HBG1 and HBG2 expression levels. Gene expression correlation identified JHDM1D-AS1(KDM7A-DT), a non-coding RNA associated with angiogenesis, enhanced GATA1 and decreased JAK-STAT signaling to correlate with HBG1 and HBG2 mRNA levels. These data suggest novel regulatory mechanisms for fetal hemoglobin regulation, which may offer innovative therapeutic approaches for SCA.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9262
Author(s):  
Wen-Jing Zeng ◽  
Yong-Long Yang ◽  
Zhi-Peng Wen ◽  
Peng Chen ◽  
Xiao-Ping Chen ◽  
...  

Background Lower-grade gliomas (LGGs) is characteristic with great difference in prognosis. Due to limited prognostic biomarkers, it is urgent to identify more molecular markers to provide a more objective and accurate tumor classification system for LGGs. Methods In the current study, we performed an integrated analysis of gene expression data and genome-wide methylation data to determine novel prognostic genes and methylation sites in LGGs. Results To determine genes that differentially expressed between 44 short-term survivors (<2 years) and 48 long-term survivors (≥2 years), we searched LGGs TCGA RNA-seq dataset and identified 106 differentially expressed genes. SERPINA5 and TIMP1 were selected for further study. Kaplan–Meier plots showed that SERPINA5 and TIMP1 expression were significantly correlated with overall survival (OS) and relapse-free survival (RFS) in TCGA LGGs patients. We next validated the correlation between the candidate genes expression and clinical outcome in CGGA LGGs patients. Multivariate analysis showed that TIMP1 mRNA expression had a significant prognostic value independent of other variables (HR = 4.825, 95% CI = 1.370–17.000, P = 0.014). Then, differential methylation sites were identified from differentially candidate gene expression groups, and all four methylation sites were significantly negatively correlated with gene expression (spearman r <  − 0.5, P < 0.0001). Moreover, hyper-methylation of four methylation sites indicated better OS (P < 0.05), and three of them also shown statistical significantly association with better RFS, except for SERPINA5 cg15509705 (P = 0.0762). Conclusion Taken together, these findings indicated that the gene expression and methylation of SERPINA5 and TIMP1 may serve as prognostic predictors in LGGs and may help to precise the current histology-based tumors classification system and to provide better stratification for future clinical trials.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Cynthia C. Jose ◽  
Zhenjia Wang ◽  
Vinay Singh Tanwar ◽  
Xiaoru Zhang ◽  
Chongzhi Zang ◽  
...  

Abstract Background Nickel is an occupational and environmental toxicant associated with a number of diseases in humans including pulmonary fibrosis, bronchitis and lung and nasal cancers. Our earlier studies showed that the nickel-exposure-induced genome-wide transcriptional changes, which persist even after the termination of exposure may underlie nickel pathogenesis. However, the mechanisms that drive nickel-induced persistent changes to the transcriptome remain elusive. Results To elucidate the mechanisms that underlie nickel-induced long-term transcriptional changes, in this study, we examined the transcriptome and the epigenome of human lung epithelial cells during nickel exposure and after the termination of exposure. We identified two categories of persistently differentially expressed genes: (i) the genes that were differentially expressed during nickel exposure; and (ii) the genes that were differentially expressed only after the termination of exposure. Interestingly, > 85% of the nickel-induced gene expression changes occurred only after the termination of exposure. We also found extensive genome-wide alterations to the activating histone modification, H3K4me3, after the termination of nickel exposure, which coincided with the post-exposure gene expression changes. In addition, we found significant post-exposure alterations to the repressive histone modification, H3K27me3. Conclusion Our results suggest that while modest first wave of transcriptional changes occurred during nickel exposure, extensive transcriptional changes occurred during a second wave of transcription for which removal of nickel ions was essential. By uncovering a new category of transcriptional and epigenetic changes, which occur only after the termination of exposure, this study provides a novel understanding of the long-term deleterious consequences of nickel exposure on human health.


2020 ◽  
Vol 117 (21) ◽  
pp. 11459-11470 ◽  
Author(s):  
Qian Bian ◽  
Erika C. Anderson ◽  
Qiming Yang ◽  
Barbara J. Meyer

Genomic regions preferentially associate with regions of similar transcriptional activity, partitioning genomes into active and inactive compartments within the nucleus. Here we explore mechanisms controlling genome compartment organization inCaenorhabditis elegansand investigate roles for compartments in regulating gene expression. Distal arms ofC. eleganschromosomes, which are enriched for heterochromatic histone modifications H3K9me1/me2/me3, interact with each other bothin cisandin trans,while interacting less frequently with central regions, leading to genome compartmentalization. Arms are anchored to the nuclear periphery via the nuclear envelope protein CEC-4, which binds to H3K9me. By performing genome-wide chromosome conformation capture experiments (Hi-C), we showed that eliminating H3K9me1/me2/me3 through mutations in the methyltransferase genesmet-2andset-25significantly impaired formation of inactive Arm and active Center compartments.cec-4mutations also impaired compartmentalization, but to a lesser extent. We found that H3K9me promotes compartmentalization through two distinct mechanisms: Perinuclear anchoring of chromosome arms via CEC-4 to promote theircisassociation, and an anchoring-independent mechanism that compacts individual chromosome arms. In bothmet-2 set-25andcec-4mutants, no dramatic changes in gene expression were found for genes that switched compartments or for genes that remained in their original compartment, suggesting that compartment strength does not dictate gene-expression levels. Furthermore, H3K9me, but not perinuclear anchoring, also contributes to formation of another prominent feature of chromosome organization, megabase-scale topologically associating domains on X established by the dosage compensation condensin complex. Our results demonstrate that H3K9me plays crucial roles in regulating genome organization at multiple levels.


2018 ◽  
Vol 35 (16) ◽  
pp. 2718-2723 ◽  
Author(s):  
Tamir Tuller ◽  
Alon Diament ◽  
Avital Yahalom ◽  
Assaf Zemach ◽  
Shimshi Atar ◽  
...  

Abstract Motivation The COP9 signalosome is a highly conserved multi-protein complex consisting of eight subunits, which influences key developmental pathways through its regulation of protein stability and transcription. In Arabidopsis thaliana, mutations in the COP9 signalosome exhibit a number of diverse pleiotropic phenotypes. Total or partial loss of COP9 signalosome function in Arabidopsis leads to misregulation of a number of genes involved in DNA methylation, suggesting that part of the pleiotropic phenotype is due to global effects on DNA methylation. Results We determined and analyzed the methylomes and transcriptomes of both partial- and total-loss-of-function Arabidopsis mutants of the COP9 signalosome. Our results support the hypothesis that the COP9 signalosome has a global genome-wide effect on methylation and that this effect is at least partially encoded in the DNA. Our analyses suggest that COP9 signalosome-dependent methylation is related to gene expression regulation in various ways. Differentially methylated regions tend to be closer in the 3D conformation of the genome to differentially expressed genes. These results suggest that the COP9 signalosome has a more comprehensive effect on gene expression than thought before, and this is partially related to regulation of methylation. The high level of COP9 signalosome conservation among eukaryotes may also suggest that COP9 signalosome regulates methylation not only in plants but also in other eukaryotes, including humans. Supplementary information Supplementary data are available at Bioinformatics online.


2020 ◽  
Vol 21 (24) ◽  
pp. 9719
Author(s):  
Marco Spreafico ◽  
Eleonora Mangano ◽  
Mara Mazzola ◽  
Clarissa Consolandi ◽  
Roberta Bordoni ◽  
...  

Transcriptional changes normally occur during development but also underlie differences between healthy and pathological conditions. Transcription factors or chromatin modifiers are involved in orchestrating gene activity, such as the cohesin genes and their regulator NIPBL. In our previous studies, using a zebrafish model for nipblb knockdown, we described the effect of nipblb loss-of-function in specific contexts, such as central nervous system development and hematopoiesis. However, the genome-wide transcriptional impact of nipblb loss-of-function in zebrafish embryos at diverse developmental stages remains under investigation. By RNA-seq analyses in zebrafish embryos at 24 h post-fertilization, we examined genome-wide effects of nipblb knockdown on transcriptional programs. Differential gene expression analysis revealed that nipblb loss-of-function has an impact on gene expression at 24 h post fertilization, mainly resulting in gene inactivation. A similar transcriptional effect has also been reported in other organisms, supporting the use of zebrafish as a model to understand the role of Nipbl in gene regulation during early vertebrate development. Moreover, we unraveled a connection between nipblb-dependent differential expression and gene expression patterns of hematological cell populations and AML subtypes, enforcing our previous evidence on the involvement of NIPBL-related transcriptional dysregulation in hematological malignancies.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2357-2357
Author(s):  
Frank G. Rucker ◽  
Lars Bullinger ◽  
Hans A. Kestler ◽  
Peter Lichter ◽  
Konstanze Dohner ◽  
...  

Abstract Approximately 10 to 15 % of acute myeloid leukemia (AML) cases exhibit complex karyotypes, i.e., three or more chromosome abnormalities without presence of a specific fusion transcript. To identify novel genomic regions of interest in AML with complex karyotypes we applied comparative genomic hybridization to microarrays (matrix-CGH) allowing high-resolution genome-wide screening of genomic imbalances. We designed a microarray consisting of 2799 different BAC- or PAC-vectors. A set of 1500 of these clones covers the whole human genome with a physical distance of approximately 1.5 Mb. The remaining 1299 clones either contiguously span genomic regions known to be frequently involved in hematologic malignancies (e.g., 1p, 2p, 3q, 7q, 9p, 11q, 12q, 13q, 17p, 18q) (n=600) or contain oncogenes or tumor suppressor genes (n=699). Using this microarray platform, 83 AML cases with complex karyotypes were analyzed. Genomic losses were found more frequently than gains; the most frequent losses were deletions of 5q (71%), 17p (53%), 7q (48%); followed by deletions of 18q (30%), 16q (28%), 3p and 12q (20% each), 12p (18%), 20q (17%), and 11q (12%). The most frequent genomic gains were trisomies of 11q (39%) and 8q (31%); followed by trisomies of 1p (22%), 21q (20%), 9p (14%), 22q (13%), 13q (12%), and 6p (10%). In part, some critical segments were delineated to genomic fragments of 0.8 to a few megabase pairs in size. In lost/gained regions parallel analysis of gene expression using microarray technology detected a gene dosage effect with significant lower/higher average gene expression levels across the genes located in the respective regions. Furthermore, 47 high-level DNA amplifications in 19 different regions were identified; amplifications occurring in at least two cases mapped to (candidate genes in the amplicon) 11q23.3-q24.1 (n=10; ETS, FLI1); 11q23.3 (n=8; MLL, DDX6); 21q22 (n=5; ERG, ETS2); 13q12 (n=3; CDX2, FLT1, FLT3, PAN3); 8q24 (n=3; C8FW, MYC); 9p24 (n=2; JAK2); 12p13 (n=2; FGF6, CCND2); and 20q11 (n=2; ID1, BCL2L1). Parallel analysis displayed overexpressed candidate genes in critical amplified region, e.g., C8FW and MYC in 8q24. In conclusion, using high-resolution genome-wide screening tools such as matrix-CGH allows to unravel the enormous genetic diversity of AML cases with complex karyotypes, and correlation with global gene expression studies facilitates the delineation of disease-related candidate genes located in the critical regions.


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