Reproductive phasiRNAs regulate reprogramming of gene expression and meiotic progression in rice

AbstractPlant spermatogenesis is a complex process that directly affects crop breeding. A rapid change in gene abundance occurs at early meiosis prophase, when gene regulation is selective. However, how these genes are regulated remains unknown. Here, we show that rice reproductive phasiRNAs are essential for the elimination of a specific set of RNAs during meiotic prophase I. These phasiRNAs cleave target mRNAs in a regulatory manner such that one phasiRNA can target more than one gene, and/or a single gene can be targeted by more than one phasiRNA to efficiently silence target genes. Our investigation of phasiRNA-knockdown and PHAS-edited transgenic plants demonstrates that phasiRNAs and their nucleotide variations are required for meiosis progression and fertility. This study highlights the importance of reproductive phasiRNAs for the reprogramming of gene expression during meiotic progression and establishes a basis for future studies on the roles of phasiRNAs with a goal of crop improvement.

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Alternative splicing landscapes in Arabidopsis thaliana across tissues and stress conditions highlight major functional differences with animals

Genome Biology ◽

10.1186/s13059-020-02258-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Guiomar Martín ◽

Yamile Márquez ◽

Federica Mantica ◽

Paula Duque ◽

Manuel Irimia

Keyword(s):

Gene Expression ◽

Arabidopsis Thaliana ◽

Alternative Splicing ◽

Stress Responses ◽

Target Genes ◽

Intron Retention ◽

Single Gene ◽

Exon Skipping ◽

Environmental Response ◽

Biotic Stresses

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.

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Circular RNAs as microRNA sponges: evidence and controversies

Essays in Biochemistry ◽

10.1042/ebc20200060 ◽

2021 ◽

Author(s):

Morten T. Jarlstad Olesen ◽

Lasse S. Kristensen

Keyword(s):

Gene Regulation ◽

Target Genes ◽

Research Field ◽

Circular Rnas ◽

Transcriptional Level ◽

Additional Layer ◽

Complex Process ◽

Non Coding Rnas ◽

New Research ◽

Microrna Sponges

Abstract Gene expression in eukaryotic cells is a complex process encompassing several layers of regulation at the transcriptional and post-transcriptional levels. At the post-transcriptional level, microRNAs (miRs) are key regulatory molecules that function by binding directly to mRNAs. This generally leads to less efficient translation of the target mRNAs. More recently, an additional layer of gene regulation has been discovered, as other molecules, including circular RNAs (circRNAs), may bind to miRs and thereby function as sponges or decoys resulting in increased expression of the corresponding miR target genes. The circRNAs constitute a large class of mainly non-coding RNAs, which have been extensively studied in recent years, in particular in the cancer research field where many circRNAs have been proposed to function as miR sponges. Here, we briefly describe miR-mediated gene regulation and the extra layer of regulation that is imposed by the circRNAs. We describe techniques and methodologies that are commonly used to investigate potential miR sponging properties of circRNAs and discuss major pitfalls and controversies within this relatively new research field.

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HOXA9 promotes MYC-mediated leukemogenesis by maintaining gene expression for multiple anti-apoptotic pathways

10.1101/2020.10.20.347765 ◽

2020 ◽

Author(s):

Ryo Miyamoto ◽

Akinori Kanai ◽

Hiroshi Okuda ◽

Satoshi Takahashi ◽

Hirotaka Matsui ◽

...

Keyword(s):

Gene Expression ◽

Target Genes ◽

Single Gene ◽

Gene Transduction ◽

Hematopoietic Precursor ◽

Apoptotic Pathways

AbstractHOXA9 is often highly expressed in leukemias. However, its precise roles in leukemogenesis remain elusive. Here, we show that HOXA9 maintains gene expression for multiple anti-apoptotic pathways to promote leukemogenesis. In MLL-rearranged leukemia, MLL fusion directly activates the expression of MYC and HOXA9. Combined expression of MYC and HOXA9 induced leukemia, whereas single gene transduction of either did not, indicating a synergy between MYC and HOXA9. HOXA9 sustained expression of the genes implicated to the hematopoietic precursor identity when expressed in hematopoietic precursors, but did not reactivate it once silenced. Among the HOXA9 target genes, BCL2 and SOX4 synergistically induced leukemia with MYC. Not only BCL2, but also SOX4 suppressed apoptosis, indicating that multiple anti-apoptotic pathways underlie cooperative leukemogenesis by HOXA9 and MYC. These results demonstrate that HOXA9 is a key transcriptional maintenance factor which promotes MYC-mediated leukemogenesis, potentially explaining why HOXA9 is highly expressed in many leukemias.

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Alternative splicing landscapes in Arabidopsis thaliana across tissues and stress conditions highlight major functional differences with animals

10.1101/2020.11.10.374751 ◽

2020 ◽

Author(s):

Guiomar Martín ◽

Yamile Márquez ◽

Federica Mantica ◽

Paula Duque ◽

Manuel Irimia

Keyword(s):

Gene Expression ◽

Alternative Splicing ◽

Stress Responses ◽

Target Genes ◽

Intron Retention ◽

Single Gene ◽

Exon Skipping ◽

Environmental Response ◽

Biotic Stresses ◽

External Stimuli

AbstractBackgroundAlternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing.ResultsWe generated a massive resource for A. thaliana (PastDB; pastdb.crg.eu), comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets revealed that A. thaliana shows high levels of AS (similar to fruitflies) and that, compared to animals, disproportionately uses AS for stress responses. We identified core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that was tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, were overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion.ConclusionsNon-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.

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Cistrome-GO: a web server for functional enrichment analysis of transcription factor ChIP-seq peaks

Nucleic Acids Research ◽

10.1093/nar/gkz332 ◽

2019 ◽

Vol 47 (W1) ◽

pp. W206-W211 ◽

Cited By ~ 15

Author(s):

Shaojuan Li ◽

Changxin Wan ◽

Rongbin Zheng ◽

Jingyu Fan ◽

Xin Dong ◽

...

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Transcription Factor ◽

Target Genes ◽

Enrichment Analysis ◽

Functional Enrichment Analysis ◽

Functional Enrichment ◽

Differential Gene ◽

Direct Target ◽

Human And Mouse

AbstractCharacterizing the ontologies of genes directly regulated by a transcription factor (TF), can help to elucidate the TF’s biological role. Previously, we developed a widely used method, BETA, to integrate TF ChIP-seq peaks with differential gene expression (DGE) data to infer direct target genes. Here, we provide Cistrome-GO, a website implementation of this method with enhanced features to conduct ontology analyses of gene regulation by TFs in human and mouse. Cistrome-GO has two working modes: solo mode for ChIP-seq peak analysis; and ensemble mode, which integrates ChIP-seq peaks with DGE data. Cistrome-GO is freely available at http://go.cistrome.org/.

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A neuron-optimized CRISPR/dCas9 activation system for robust and specific gene regulation

10.1101/371500 ◽

2018 ◽

Cited By ~ 2

Author(s):

Katherine E. Savell ◽

Svitlana V. Bach ◽

Morgan E. Zipperly ◽

Jasmin S. Revanna ◽

Nicholas A. Goska ◽

...

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Transcriptional Activation ◽

Target Genes ◽

Adult Brain ◽

Model Systems ◽

Neuronal Cultures ◽

Specific Gene ◽

Highly Efficient ◽

Study Gene Expression

Recent developments in CRISPR-based gene editing have provided new avenues to interrogate gene function. However, application of these tools in the central nervous system has been delayed due to difficulties in transgene expression in post-mitotic neurons. Here, we present a highly efficient, neuron-optimized dual lentiviral CRISPR-based transcriptional activation (CRISPRa) system to drive gene expression in primary neuronal cultures and the adult brain of rodent model systems. We demonstrate robust, modular, and tunable induction of endogenous target genes as well as multiplexed gene regulation necessary for investigation of complex transcriptional programs. CRISPRa targeting unique promoters in the complex multi-transcript gene Brain-derived neurotrophic factor (Bdnf) revealed both transcript- and genome-level selectivity of this approach, in addition to highlighting downstream transcriptional and physiological consequences of Bdnf regulation. Finally, we illustrate that CRISPRa is highly efficient in vivo, resulting in increased protein levels of a target gene in diverse brain structures. Taken together, these results demonstrate that CRISPRa is an efficient and selective method to study gene expression programs in brain health and disease.

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Histone crotonylation-centric gene regulation

Epigenetics & Chromatin ◽

10.1186/s13072-021-00385-9 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Kun Li ◽

Ziqiang Wang

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Gene Transcription ◽

Target Genes ◽

Regulatory Elements ◽

Related Gene ◽

Post Translational Modification ◽

Histone Lysine ◽

Dna Regulatory Elements

AbstractHistone crotonylation is a recently described post-translational modification that occurs at multiple identified histone lysine crotonylation sites. An increasing number of studies have demonstrated that histone crotonylation at DNA regulatory elements plays an important role in the activation of gene transcription. However, among others, we have shown that elevated cellular crotonylation levels result in the inhibition of endocytosis-related gene expression and pro-growth gene expression, implicating the complexity of histone crotonylation in gene regulation. Therefore, it is important to understand how histone crotonylation is regulated and how it, in turn, regulates the expression of its target genes. In this review, we summarize the regulatory factors that control histone crotonylation and discuss the role of different histone crotonylation sites in regulating gene expression, while providing novel insights into the central role of histone crotonylation in gene regulation.

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HOXA9 promotes MYC-mediated leukemogenesis by maintaining gene expression for multiple anti-apoptotic pathways

eLife ◽

10.7554/elife.64148 ◽

2021 ◽

Vol 10 ◽

Author(s):

Ryo Miyamoto ◽

Akinori Kanai ◽

Hiroshi Okuda ◽

Yosuke Komata ◽

Satoshi Takahashi ◽

...

Keyword(s):

Gene Expression ◽

Target Genes ◽

Single Gene ◽

Gene Transduction ◽

Hematopoietic Precursor ◽

Apoptotic Pathways

HOXA9 is often highly expressed in leukemias. However, its precise roles in leukemogenesis remain elusive. Here, we show that HOXA9 maintains gene expression for multiple anti-apoptotic pathways to promote leukemogenesis. In MLL fusion-mediated leukemia, MLL fusion directly activates the expression of MYC and HOXA9. Combined expression of MYC and HOXA9 induced leukemia, whereas single gene transduction of either did not, indicating a synergy between MYC and HOXA9. HOXA9 sustained expression of the genes implicated in the hematopoietic precursor identity when expressed in hematopoietic precursors, but did not reactivate it once silenced. Among the HOXA9 target genes, BCL2 and SOX4 synergistically induced leukemia with MYC. Not only BCL2, but also SOX4 suppressed apoptosis, indicating that multiple anti-apoptotic pathways underlie cooperative leukemogenesis by HOXA9 and MYC. These results demonstrate that HOXA9 is a crucial transcriptional maintenance factor that promotes MYC-mediated leukemogenesis, potentially explaining why HOXA9 is highly expressed in many leukemias.

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Genetic Regulation of Salivary Proteins in Rodents

Critical Reviews in Oral Biology & Medicine ◽

10.1177/10454411910020020101 ◽

1991 ◽

Vol 2 (2) ◽

pp. 139-151 ◽

Cited By ~ 2

Author(s):

Eleni Kousvelari ◽

Lawrence A. Tabak

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Salivary Gland ◽

Salivary Glands ◽

Genetic Regulation ◽

Salivary Proteins ◽

Parotid Glands ◽

Future Studies ◽

Regulated Expression ◽

Rat Parotid

The presence of a protein in the cell is the result of a complex pathway that is known by the term gene expression. In this article we review the existing literature on the structure and expression of representative salivary gland genes and their regulated expression during development and upon extracellular stimulation. The expression of one of the "nuclear" protooncogenes, c-fos, in rat parotid glands is also discussed. Finally, we present some suggestions for future studies that will help to understand the mechanisms leading to gene regulation in rat salivary glands.

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Differential Roles of Hypoxia-Inducible Factor 1α (HIF-1α) and HIF-2α in Hypoxic Gene Regulation

Molecular and Cellular Biology ◽

10.1128/mcb.23.24.9361-9374.2003 ◽

2003 ◽

Vol 23 (24) ◽

pp. 9361-9374 ◽

Cited By ~ 838

Author(s):

Cheng-Jun Hu ◽

Li-Yi Wang ◽

Lewis A. Chodosh ◽

Brian Keith ◽

M. Celeste Simon

Keyword(s):

Gene Expression ◽

Gene Regulation ◽

Target Genes ◽

Hypoxia Inducible Factor ◽

Embryonic Stem ◽

Mouse Embryonic Fibroblast ◽

Hek293 Cells ◽

Specific Gene ◽

Transcriptional Responses ◽

Inducible Genes

ABSTRACT Transcriptional responses to hypoxia are primarily mediated by hypoxia-inducible factor (HIF), a heterodimer of HIF-α and the aryl hydrocarbon receptor nuclear translocator subunits. The HIF-1α and HIF-2α subunits are structurally similar in their DNA binding and dimerization domains but differ in their transactivation domains, implying they may have unique target genes. Previous studies using Hif-1α−/− embryonic stem and mouse embryonic fibroblast cells show that loss of HIF-1α eliminates all oxygen-regulated transcriptional responses analyzed, suggesting that HIF-2α is dispensable for hypoxic gene regulation. In contrast, HIF-2α has been shown to regulate some hypoxia-inducible genes in transient transfection assays and during embryonic development in the lung and other tissues. To address this discrepancy, and to identify specific HIF-2α target genes, we used DNA microarray analysis to evaluate hypoxic gene induction in cells expressing HIF-2α but not HIF-1α. In addition, we engineered HEK293 cells to express stabilized forms of HIF-1α or HIF-2α via a tetracycline-regulated promoter. In this first comparative study of HIF-1α and HIF-2α target genes, we demonstrate that HIF-2α does regulate a variety of broadly expressed hypoxia-inducible genes, suggesting that its function is not restricted, as initially thought, to endothelial cell-specific gene expression. Importantly, HIF-1α (and not HIF-2α) stimulates glycolytic gene expression in both types of cells, clearly showing for the first time that HIF-1α and HIF-2α have unique targets.

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