Through a generation darkly: small RNAs in the gametophyte

2010 ◽  
Vol 38 (2) ◽  
pp. 617-621 ◽  
Author(s):  
Robert T. Grant-Downton
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Small Rnas ◽  
Recent Progress ◽  
Regulation Of Gene Expression ◽  
Non Coding Rnas ◽  
And Function

The various classes of small non-coding RNAs are a fundamentally important component of the transcriptome. These molecules have roles in many essential processes such as regulation of gene expression at the transcriptional and post-transcriptional levels, guidance of DNA methylation and defence against selfish replicators such as transposons. Their diversity and functions in the sporophytic generation of angiosperms is well explored compared with the gametophytic generation, where little is known about them. Recent progress in understanding their abundance, diversity and function in the gametophyte is reviewed.

scholarly journals miR-155 Inhibits Expression of the MEF2A Protein to Repress Skeletal Muscle Differentiation

2011 ◽  
Vol 286 (41) ◽  
pp. 35339-35346 ◽  
Author(s):  
Hee Young Seok ◽  
Mariko Tatsuguchi ◽  
Thomas E. Callis ◽  
Aibin He ◽  
William T. Pu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Rnas ◽  
Myogenic Differentiation ◽  
Regulation Of Gene Expression ◽  
Myoblast Differentiation ◽  
Transcriptional Level ◽  
Muscle Gene Expression ◽  
Important Regulator ◽  
Non Coding Rnas ◽  
Muscle Gene

microRNAs (miRNAs) are 21–23-nucleotide non-coding RNAs. It has become more and more evident that this class of small RNAs plays critical roles in the regulation of gene expression at the post-transcriptional level. MEF2A is a member of the MEF2 (myogenic enhancer factor 2) family of transcription factors. Prior report showed that the 3′-untranslated region (3′-UTR) of the Mef2A gene mediated its repression; however, the molecular mechanism underlying this intriguing observation was unknown. Here, we report that MEF2A is repressed by miRNAs. We identify miR-155 as one of the primary miRNAs that significantly represses the expression of MEF2A. We show that knockdown of the Mef2A gene by siRNA impairs myoblast differentiation. Similarly, overexpression of miR-155 leads to the repression of endogenous MEF2A expression and the inhibition of myoblast differentiation. Most importantly, reintroduction of MEF2A in miR-155 overexpressed myoblasts was able to partially rescue the miR-155-induced myoblast differentiation defect. Our data therefore establish miR-155 as an important regulator of MEF2A expression and uncover its function in muscle gene expression and myogenic differentiation.

scholarly journals Construction and investigation of lncRNA-miRNA-mRNA ceRNA network in thymic epithelial neoplasms

2020 ◽  
Author(s):  
Hanxiao Tang ◽  
Shuyu Ge ◽  
Pingping Sun
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Regulation Of Gene Expression ◽  
The Cancer Genome Atlas ◽  
Rank Test ◽  
Protein Coding ◽  
Cerna Network ◽  
Non Coding Rnas ◽  
Epithelial Neoplasms ◽  
And Function

Abstract Background Competing endogenous RNA (ceRNA) networks may be used to relate the functions of protein-coding mRNAs with those of the non-coding RNAs, such as microRNAs (miRNAs) and the long non-coding RNAs (lncRNAs). ceRNAs enable the post-transcriptional regulation of gene expression by competing for the shared miRNAs. However, the role and function of the lncRNA-miRNA-mRNA ceRNA network in thymic epithelial neoplasms (TEN) remains unknown. Methods The miRNA, mRNA, and lncRNA expression profiles of 124 patients with TEN were downloaded from The Cancer Genome Atlas. We identified the differentially expressed (DE) miRNAs, mRNAs, and lncRNAs using the limma package in R software. The GDCRNATools package was used for the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations. Cytoscape software was used to construct the lncRNA-miRNA-mRNA ceRNA network. The Gene Expression Profiling Interactive Analysis platform was used to estimate the overall survival (OS) rates of the patients. Survival curves were analyzed using the log-rank test. Finally, the mRNAs in the ceRNA network were analyzed using the GOplot package in R. Results A total of 1513, 188, and 579 TEN-specific mRNAs, lncRNAs, and miRNAs, respectively, were identified. The lncRNA-miRNA-mRNA ceRNA network was constructed, and included 53 mRNAs, 4 lncRNAs, and 27 miRNAs. A total of 10 DEmRNAs (DLX2, C8orf88, CD38, GATA3, MAL, FOXQ1, FOLH1, NLRP12, HJURP, and ACSM1) and 1 lncRNA (SNHG3) were found to be significantly associated with OS ( P <0.05). Conclusion In this study, we constructed a lncRNA-miRNA-mRNA ceRNA gene regulatory network for TEN, and identified potential prognostic and diagnostic biomarkers, as well as therapeutic targets, for the disease.

scholarly journals Targeting riboswitches with synthetic small RNAs for metabolic engineering

2021 ◽  
Author(s):  
Milca Rachel da Costa Ribeiro Lins ◽  
Laura Araujo da Silva Amorim ◽  
Graciely Gomes Correa ◽  
Bruno Willian Picao ◽  
Matthias Mack ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rational Design ◽  
Regulation Of Gene Expression ◽  
Cellular Systems ◽  
Producer Strain ◽  
Natural Systems ◽  
Single Genome ◽  
Non Coding Rnas ◽  
And Function ◽  
Activate Gene

Our growing knowledge of the diversity of non-coding RNAs in natural systems and our deepening knowledge of RNA folding and function have fomented the rational design of RNA regulators. Based on that knowledge, we designed and implemented a small RNA (sRNA) tool to target bacterial riboswitches and activate gene expression. The synthetic sRNA is suitable for the regulation of gene expression both in cell-free and in cellular systems. It targets riboswitches to promote the antitermination folding regardless the cognate metabolite concentration. Therefore, it prevents transcription termination increasing gene expression up to 103-fold. We successfully used sRNA arrays for multiplex targeting of riboswitches. Finally, we used the synthetic sRNA to engineer an improved riboflavin producer strain. The easiness to design and construct, and the fact that the riboswitch-targeting sRNA works as a single genome copy, make it an attractive tool for engineering industrial metabolite-producing strains.

scholarly journals DNA methylation and regulation of gene expression: Guardian of our health

The Nucleus ◽  
2021 ◽  
Author(s):  
Gaurab Aditya Dhar ◽  
Shagnik Saha ◽  
Parama Mitra ◽  
Ronita Nag Chaudhuri
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Regulation Of Gene Expression

scholarly journals Concerted genomic and epigenomic changes accompany stabilization of Arabidopsis allopolyploids

2021 ◽  
Vol 5 (10) ◽  
pp. 1382-1393
Author(s):  
Xinyu Jiang ◽  
Qingxin Song ◽  
Wenxue Ye ◽  
Z. Jeffrey Chen
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Small Rnas ◽  
Structural Variation ◽  
Self Incompatibility ◽  
Polyploid Evolution ◽  
Genomic Variations ◽  
Conserved Gene ◽  
Arabidopsis Suecica ◽  
Affect Gene Expression

AbstractDuring evolution successful allopolyploids must overcome ‘genome shock’ between hybridizing species but the underlying process remains elusive. Here, we report concerted genomic and epigenomic changes in resynthesized and natural Arabidopsis suecica (TTAA) allotetraploids derived from Arabidopsisthaliana (TT) and Arabidopsisarenosa (AA). A. suecica shows conserved gene synteny and content with more gene family gain and loss in the A and T subgenomes than respective progenitors, although A. arenosa-derived subgenome has more structural variation and transposon distributions than A. thaliana-derived subgenome. These balanced genomic variations are accompanied by pervasive convergent and concerted changes in DNA methylation and gene expression among allotetraploids. The A subgenome is hypomethylated rapidly from F1 to resynthesized allotetraploids and convergently to the T-subgenome level in natural A. suecica, despite many other methylated loci being inherited from F1 to all allotetraploids. These changes in DNA methylation, including small RNAs, in allotetraploids may affect gene expression and phenotypic variation, including flowering, silencing of self-incompatibility and upregulation of meiosis- and mitosis-related genes. In conclusion, concerted genomic and epigenomic changes may improve stability and adaptation during polyploid evolution.

scholarly journals Long non-coding RNAs in brain tumors

NAR Cancer ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Keisuke Katsushima ◽  
George Jallo ◽  
Charles G Eberhart ◽  
Ranjan J Perera
Keyword(s):  
Gene Expression ◽  
Brain Tumors ◽  
Brain Cancer ◽  
Regulation Of Gene Expression ◽  
Therapeutic Targets ◽  
Diagnostic Biomarkers ◽  
Cancer Pathogenesis ◽  
Current State ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation

Abstract Long non-coding RNAs (lncRNAs) have been found to be central players in the epigenetic, transcriptional and post-transcriptional regulation of gene expression. There is an accumulation of evidence on newly discovered lncRNAs, their molecular interactions and their roles in the development and progression of human brain tumors. LncRNAs can have either tumor suppressive or oncogenic functions in different brain cancers, making them attractive therapeutic targets and biomarkers for personalized therapy and precision diagnostics. Here, we summarize the current state of knowledge of the lncRNAs that have been implicated in brain cancer pathogenesis, particularly in gliomas and medulloblastomas. We discuss their epigenetic regulation as well as the prospects of using lncRNAs as diagnostic biomarkers and therapeutic targets in patients with brain tumors.

scholarly journals On the origin and evolutionary consequences of gene body DNA methylation

2016 ◽  
Vol 113 (32) ◽  
pp. 9111-9116 ◽  
Author(s):  
Adam J. Bewick ◽  
Lexiang Ji ◽  
Chad E. Niederhuth ◽  
Eva-Maria Willing ◽  
Brigitte T. Hofmeister ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Recombinant Inbred Lines ◽  
Dna Methyltransferases ◽  
Inbred Lines ◽  
Gene Body ◽  
Gene Body Methylation ◽  
Eutrema Salsugineum ◽  
And Function ◽  
Evolutionary Consequences

In plants, CG DNA methylation is prevalent in the transcribed regions of many constitutively expressed genes (gene body methylation; gbM), but the origin and function of gbM remain unknown. Here we report the discovery that Eutrema salsugineum has lost gbM from its genome, to our knowledge the first instance for an angiosperm. Of all known DNA methyltransferases, only CHROMOMETHYLASE 3 (CMT3) is missing from E. salsugineum. Identification of an additional angiosperm, Conringia planisiliqua, which independently lost CMT3 and gbM, supports that CMT3 is required for the establishment of gbM. Detailed analyses of gene expression, the histone variant H2A.Z, and various histone modifications in E. salsugineum and in Arabidopsis thaliana epigenetic recombinant inbred lines found no evidence in support of any role for gbM in regulating transcription or affecting the composition and modification of chromatin over evolutionary timescales.

scholarly journals TET2 coactivates gene expression through demethylation of enhancers

2018 ◽  
Vol 4 (11) ◽  
pp. eaau6986 ◽  
Author(s):  
Lu Wang ◽  
Patrick A. Ozark ◽  
Edwin R. Smith ◽  
Zibo Zhao ◽  
Stacy A. Marshall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Regulation Of Gene Expression ◽  
Estrogen Receptor Α ◽  
Dna Demethylation ◽  
Estrogen Response ◽  
Dna Base ◽  
Modified Dna ◽  
Global Increase ◽  
Methylation Patterns

The tet methylcytosine dioxygenase 2 (TET2) enzyme catalyzes the conversion of the modified DNA base 5-methylcytosine to 5-hydroxymethylcytosine. TET2 is frequently mutated or dysregulated in multiple human cancers, and loss of TET2 is associated with changes in DNA methylation patterns. Here, using newly developed TET2-specific antibodies and the estrogen response as a model system for studying the regulation of gene expression, we demonstrate that endogenous TET2 occupies active enhancers and facilitates the proper recruitment of estrogen receptor α (ERα). Knockout of TET2 by CRISPR-CAS9 leads to a global increase of DNA methylation at enhancers, resulting in attenuation of the estrogen response. We further identified a positive feedback loop between TET2 and ERα, which further requires MLL3 COMPASS at these enhancers. Together, this study reveals an epigenetic axis coordinating a transcriptional program through enhancer activation via DNA demethylation.

scholarly journals Nurse cell-derived small RNAs define paternal epigenetic inheritance in Arabidopsis

2021 ◽  
Author(s):  
Jincheng Long ◽  
James Walker ◽  
Wenjing She ◽  
Billy Aldridge ◽  
Hongbo Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Small Rnas ◽  
Nurse Cell ◽  
De Novo ◽  
Epigenetic Inheritance ◽  
Genome Integrity ◽  
Nurse Cells ◽  
Male Germline ◽  
Methylation Patterns

AbstractThe plant male germline undergoes DNA methylation reprogramming, which methylates genes de novo and thereby alters gene expression and facilitates meiosis. Why reprogramming is limited to the germline and how specific genes are chosen is unknown. Here, we demonstrate that genic methylation in the male germline, from meiocytes to sperm, is established by germline-specific siRNAs transcribed from transposons with imperfect sequence homology. These siRNAs are synthesized by meiocyte nurse cells (tapetum) via activity of the tapetum-specific chromatin remodeler CLASSY3. Remarkably, tapetal siRNAs govern germline methylation throughout the genome, including the inherited methylation patterns in sperm. Finally, we demonstrate that these nurse cell-derived siRNAs (niRNAs) silence germline transposons, thereby safeguarding genome integrity. Our results reveal that tapetal niRNAs are sufficient to reconstitute germline methylation patterns and drive extensive, functional methylation reprogramming analogous to piRNA-mediated reprogramming in animal germlines.

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