Comprehensive analysis of small RNA-seq data reveals that combination of miRNA with its isomiRs increase the accuracy of target prediction in Arabidopsis thaliana

SummaryPlant small RNAs regulate key physiological mechanisms through post-transcriptional and transcriptional silencing of gene expression. sRNAs fall into two major categories: those that are reliant on RNA Dependent RNA Polymerases (RDRs) for biogenesis and those that aren’t. Known RDR-dependent sRNAs include phased and repeat-associated short interfering RNAs, while known RDR-independent sRNAs are primarily microRNAs and other hairpin-derived sRNAs. In this study, we produced and analyzed small RNA-seq libraries from rdr1/rdr2/rdr6 triple mutant plants. Only a small fraction of all sRNA loci were RDR1/RDR2/RDR6-independent; most of these were microRNA loci or associated with predicted hairpin precursors. We found 58 previously annotated microRNA loci that were reliant on RDR1, −2, or −6 function, casting doubt on their classification. We also found 38 RDR1/2/6-independent small RNA loci that are not MIRNAs or otherwise hairpin-derived, and did not fit into other known paradigms for small RNA biogenesis. These 38 small RNA-producing loci have novel biogenesis mechanisms, and are frequently located in the vicinity of protein-coding genes. Altogether, our analysis suggest that these 38 loci represent one or more new types of small RNAs in Arabidopsis thaliana.Significance StatementSmall RNAs regulate gene expression in plants and are produced through a variety of previously-described mechanisms. Here, we examine a set of previously undiscovered small RNA-producing loci that are produced by novel mechanisms.

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Araport11: a complete reannotation of the Arabidopsis thaliana reference genome

10.1101/047308 ◽

2016 ◽

Cited By ~ 6

Author(s):

Chia-Yi Cheng ◽

Vivek Krishnakumar ◽

Agnes Chan ◽

Seth Schobel ◽

Christopher D. Town

Keyword(s):

Arabidopsis Thaliana ◽

Small Rna ◽

Noncoding Rna ◽

Model Organism ◽

Housekeeping Genes ◽

Flowering Plant ◽

Small Nuclear Rna ◽

Rna Seq ◽

Protein Coding ◽

Protein Coding Genes

ABSTRACTThe flowering plant Arabidopsis thaliana is a dicot model organism for research in many aspects of plant biology. A comprehensive annotation of its genome paves the way for understanding the functions and activities of all types of transcripts, including mRNA, noncoding RNA, and small RNA. The most recent annotation update (TAIR10) released more than five years ago had a profound impact on Arabidopsis research. Maintaining the accuracy of the annotation continues to be a prerequisite for future progress. Using an integrative annotation pipeline, we assembled tissue-specific RNA-seq libraries from 113 datasets and constructed 48,359 transcript models of protein-coding genes in eleven tissues. In addition, we annotated various classes of noncoding RNA including small RNA, long intergenic RNA, small nucleolar RNA, natural antisense transcript, small nuclear RNA, and microRNA using published datasets and in-house analytic results. Altogether, we identified 738 novel protein-coding genes, 508 novel transcribed regions, 5051 non-coding genes, and 35846 small-RNA loci that formerly eluded annotation. Analysis on the splicing events and RNA-seq based expression profile revealed the landscapes of gene structures, untranslated regions, and splicing activities to be more intricate than previously appreciated. Furthermore, we present 692 uniformly expressed housekeeping genes, 43% of whose human orthologs are also housekeeping genes. This updated Arabidopsis genome annotation with a substantially increased resolution of gene models will not only further our understanding of the biological processes of this plant model but also of other species.

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iSmaRT: a toolkit for a comprehensive analysis of small RNA-Seq data

Bioinformatics ◽

10.1093/bioinformatics/btx647 ◽

2017 ◽

Vol 33 (24) ◽

pp. 4050-4050 ◽

Cited By ~ 8

Author(s):

Riccardo Panero ◽

Antonio Rinaldi ◽

Domenico Memoli ◽

Giovanni Nassa ◽

Maria Ravo ◽

...

Keyword(s):

Small Rna ◽

Comprehensive Analysis ◽

Rna Seq

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Comprehensive Analysis of Transcriptomics and Metabolomics between the Heads and Tails of Angelica Sinensis: Genes Related to Phenylpropanoid Biosynthesis Pathway

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323999201103221952 ◽

2020 ◽

Vol 23 ◽

Author(s):

Jie Yang ◽

Chi Zhang ◽

Wei-Hong Li ◽

Tian-Er Zhang ◽

Guang-Zhong Fan ◽

...

Keyword(s):

Ferulic Acid ◽

Metabolic Regulation ◽

Comprehensive Analysis ◽

Angelica Sinensis ◽

Rna Seq ◽

Targeted Metabolomics ◽

Kegg Pathways ◽

Qrt Pcr ◽

Phenylpropanoid Biosynthesis ◽

Combined Strategy

Background:: In Traditional Chinese Medicine (TCM), the heads and tails of Angelica sinensis (Oliv.) Diels (AS) is used in treating different diseases due to their different pharmaceutical efficacies. The underline mechanisms, however, have not been fully explored. Objective:: Novel mechanisms responsible for the discrepant activities between AS heads and tails were explored by a combined strategy of transcriptomes and metabolomics. Method:: Six pairs of the heads and tails of AS roots were collected in Min County, China. Total RNA and metabolites, which were used for RNA-seq and untargeted metabolomics analysis, were respectively isolated from each AS sample (0.1 g) by Trizol and methanol reagent. Subsequently, differentially expressed genes (DEGs) and discrepant pharmaceutical metabolites were identified for comparing AS heads and tails. Key DEGs and metabolites were quantified by qRT-PCR and targeted metabolomics experiment. Results:: Comprehensive analysis of transcriptomes and metabolomics results suggested that five KEGG pathways with significant differences included 57 DEGs. Especially, fourteen DEGs and six key metabolites were relation to the metabolic regulation of Phenylpropanoid biosynthesis (PB) pathway. Results of qRT-PCR and targeted metabolomics indicated that higher levels of expression of crucial genes in PB pathway, such as PAL, CAD, COMT and peroxidase in the tail of AS were positively correlated with levels of ferulic acid-related metabolites. The average content of ferulic acid in tails (569.58162.39 nmol/g) was higher than those in the heads (168.73  67.30 nmol/g) (P˂0.01); Caffeic acid in tails (3.82  0.88 nmol/g) vs heads (1.37  0.41 nmol/g) (P˂0.01), and Cinnamic acid in tails (0.24  0.09 nmol/g) vs heads (0.14  0.02 nmol/g) (P˂0.05). Conclusion:: Our work demonstrated that overexpressed genes and accumulated metabolites derived from PB pathway might be responsible for the discrepant pharmaceutical efficacies between AS heads and tails.

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Small RNA-Sequencing: Approaches and Considerations for miRNA Analysis

Diagnostics ◽

10.3390/diagnostics11060964 ◽

2021 ◽

Vol 11 (6) ◽

pp. 964

Author(s):

Sarka Benesova ◽

Mikael Kubista ◽

Lukas Valihrach

Keyword(s):

Rna Sequencing ◽

Small Rna ◽

High Sensitivity ◽

Small Rna Sequencing ◽

Rna Seq ◽

Liquid Biopsies ◽

Comprehensive Overview ◽

Rna Molecules ◽

Novel Mirna ◽

The Many

MicroRNAs (miRNAs) are a class of small RNA molecules that have an important regulatory role in multiple physiological and pathological processes. Their disease-specific profiles and presence in biofluids are properties that enable miRNAs to be employed as non-invasive biomarkers. In the past decades, several methods have been developed for miRNA analysis, including small RNA sequencing (RNA-seq). Small RNA-seq enables genome-wide profiling and analysis of known, as well as novel, miRNA variants. Moreover, its high sensitivity allows for profiling of low input samples such as liquid biopsies, which have now found applications in diagnostics and prognostics. Still, due to technical bias and the limited ability to capture the true miRNA representation, its potential remains unfulfilled. The introduction of many new small RNA-seq approaches that tried to minimize this bias, has led to the existence of the many small RNA-seq protocols seen today. Here, we review all current approaches to cDNA library construction used during the small RNA-seq workflow, with particular focus on their implementation in commercially available protocols. We provide an overview of each protocol and discuss their applicability. We also review recent benchmarking studies comparing each protocol’s performance and summarize the major conclusions that can be gathered from their usage. The result documents variable performance of the protocols and highlights their different applications in miRNA research. Taken together, our review provides a comprehensive overview of all the current small RNA-seq approaches, summarizes their strengths and weaknesses, and provides guidelines for their applications in miRNA research.

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Faculty Opinions recommendation of RNA-seq analysis of laser microdissected Arabidopsis thaliana leaf epidermis, mesophyll and vasculature defines tissue-specific transcriptional responses to multiple stress treatments.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.740098387.793586685 ◽

2021 ◽

Author(s):

Dario Leister ◽

Tatjana Kleine

Keyword(s):

Arabidopsis Thaliana ◽

Leaf Epidermis ◽

Rna Seq ◽

Transcriptional Responses ◽

Tissue Specific ◽

Multiple Stress

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xMD-miRNA-seq to generate near in vivo miRNA expression estimates in colon epithelial cells

10.1101/333658 ◽

2018 ◽

Author(s):

Avi Z. Rosenberg ◽

Carrie Wright ◽

Karen Fox-Talbot ◽

Anandita Rajpurohit ◽

Courtney Williams ◽

...

Keyword(s):

Epithelial Cells ◽

Small Rna ◽

Mirna Expression ◽

Low Cost ◽

Expression Patterns ◽

Small Rna Sequencing ◽

Rna Seq ◽

Cell Type

AbstractAccurate, RNA-seq based, microRNA (miRNA) expression estimates from primary cells have recently been described. However, this in vitro data is mainly obtained from cell culture, which is known to alter cell maturity/differentiation status, significantly changing miRNA levels. What is needed is a robust method to obtain in vivo miRNA expression values directly from cells. We introduce expression microdissection miRNA small RNA sequencing (xMD-miRNA-seq), a method to isolate cells directly from formalin fixed paraffin-embedded (FFPE) tissues. xMD-miRNA-seq is a low-cost, high-throughput, immunohistochemistry-based method to capture any cell type of interest. As a proof-of-concept, we isolated colon epithelial cells from two specimens and performed low-input small RNA-seq. We generated up to 600,000 miRNA reads from the samples. Isolated epithelial cells, had abundant epithelial-enriched miRNA expression (miR-192; miR-194; miR-200b; miR-200c; miR-215; miR-375) and overall similar miRNA expression patterns to other epithelial cell populations (colonic enteroids and flow-isolated colon epithelium). xMD-derived epithelial cells were generally not contaminated by other adjacent cells of the colon as noted by t-SNE analysis. xMD-miRNA-seq allows for simple, economical, and efficient identification of cell-specific miRNA expression estimates. Further development will enhance rapid identification of cell-specific miRNA expression estimates in health and disease for nearly any cell type using archival FFPE material.

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Identification and validation of miRNA reference genes in poplar under pathogen stress

10.21203/rs.3.rs-225734/v1 ◽

2021 ◽

Author(s):

Lichun Zhang ◽

Xiaoqian Yang ◽

Yiyi Yin ◽

Jinxing Wang ◽

Yanwei Wang

Keyword(s):

Gene Expression ◽

Reference Gene ◽

Small Rna ◽

Reference Genes ◽

Expression Profiles ◽

Small Rna Sequencing ◽

Rna Seq ◽

Internal Standards ◽

Qrt Pcr ◽

Canker Pathogen

Abstract Quantitative real time polymerase chain reaction (qRT-PCR) is a common method to analyze gene expression. Due to differences in RNA quantity, quality, and reverse transcription efficiency between qRT-PCR samples, reference genes are used as internal standards to normalize gene expression. However, few universal genes especially miRNAs have been identified as reference so far. Therefore, it is essential to identify reference genes that can be used across various experimental conditions, stress treatments, or tissues. In this study, 14 microRNAs (miRNAs) and 5.8S rRNA were assessed for expression stability in poplar trees infected with canker pathogen. Using three reference gene analysis programs, we found that miR156g and miR156a exhibited stable expression throughout the infection process. miR156g and miR156a were then tested as internal standards to measure the expression of miR1447 and miR171c, and the results were compared to small RNA sequencing (RNA-seq) data. We found that when miR156a was used as the reference gene, the expression of miR1447 and miR171c were consistent with the small RNA-seq expression profiles. Therefore, miR156a was the most stable miRNAs examined in this study, and could be used as a reference gene in poplar under canker pathogen stress, which should enable comprehensive comparisons of miRNAs expression and avoid the bias caused by different lenth between detected miRNAs and traditional referece genes. The present study has expanded the miRNA reference genes available for gene expression studies in trees under biotic stress.

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A novel plasmid-transcribed regulatory sRNA, QfsR, controls chromosomal polycistronic mRNAs in Agrobacterium tumefaciens

10.1101/533729 ◽

2019 ◽

Author(s):

Benjamin Diel ◽

Magali Dequivre ◽

Florence Wisniewski-Dyé ◽

Ludovic Vial ◽

Florence Hommais

Keyword(s):

Agrobacterium Tumefaciens ◽

Small Rna ◽

Regulatory Networks ◽

Target Prediction ◽

Ti Plasmid ◽

Conjugative Transfer ◽

Polycistronic Mrna ◽

Cell Functions ◽

Coordinated Expression ◽

Cellular Behaviour

AbstractPlasmids are mobile DNAs that adjust host cell functions for their own amplification and dissemination. We identified QfsR, a small RNA, transcribed from the Ti plasmid in the phytopathogen Agrobacterium fabrum. QfsR is widely conserved throughout RepABC plasmids carried by Rhizobiaceae. Target prediction, expression analysis and site-direct mutagenesis experiments show that QfsR directly pairs within polycistronic mRNAs transcribed from chromosomes (involved in flagella apparatus and succinoglycan biosynthesis) and Ti plasmid (involved in conjugative transfer). QfsR leads to a coordinated expression of whole polycistronic mRNA molecules. Whereas a lack of QfsR induces motility and reduces succinoglycan production, its overproduction increases the quorum sensing signal accumulation and the Ti plasmid conjugative transfer. Based on these observations, we propose QfsR as a hub connecting regulatory networks of motility, succinoglycan biosynthesis and plasmid conjugative transfer. To our knowledge, QfsR is the first example of a plasmid-encoded sRNA that controls chromosomal polycistronic mRNAs.SignificancePlasmids represent an important cost for the hosting cell although some are beneficial under certain circumstances. Agrobacterium tumefaciens harboring Tumor inducing plasmid (pTi) are able to infect plants and to use specific resources produced by the infected cells. We characterized QfsR, a novel small RNA (sRNA) from pTi, that directly regulates plasmid polycistronic mRNA but also chromosomal ones. QfsR contributes to a fine-tuned regulation of bacterial motility, exopolysaccharide biosynthesis and conjugative dissemination of pTi. Our results report the first plasmid-encoded sRNA able to modify and coordinate cellular behaviour probably for the benefit of the plasmid dissemination and tight crosstalk between plasmid and chromosome. This could be widespread since QfsR homologs were predicted in other plasmids of Rhizobiaceae symbionts and pathogens.

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