scholarly journals The mechanism and detection of alternative splicing events in circular RNAs

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10032
Author(s):  
Xiaohan Li ◽  
Bing Zhang ◽  
Fuyu Li ◽  
Kequan Yu ◽  
Yunfei Bai
Keyword(s):  
Alternative Splicing ◽  
Large Scale ◽  
Single Gene ◽  
Expression Patterns ◽  
Functional Characterization ◽  
Full Length ◽  
Circular Rnas ◽  
Specific Expression ◽  
Enrichment Protocol

Circular RNAs (circRNAs) are considered as functional biomolecules with tissue/development-specific expression patterns. Generally, a single gene may generate multiple circRNA variants by alternative splicing, which contain different combinations of exons and/or introns. Due to the low abundance of circRNAs as well as overlapped with their linear counterparts, circRNA enrichment protocol is needed prior to sequencing. Compared with numerous algorithms, which use back-splicing reads for detection and functional characterization of circRNAs, original bioinformatic analyzing tools have been developed to large-scale determination of full-length circRNAs and accurate quantification. This review provides insights into the complexity of circRNA biogenesis and surveys the recent progresses in the experimental and bioinformatic methodologies that focus on accurately full-length circRNAs identification.

scholarly journals Function of Circular RNAs in Fish and Their Potential Application as Biomarkers

2021 ◽  
Vol 22 (13) ◽  
pp. 7119
Author(s):  
Golam Rbbani ◽  
Artem Nedoluzhko ◽  
Jorge Galindo-Villegas ◽  
Jorge M. O. Fernandes
Keyword(s):  
Growth Regulation ◽  
Functional Characterization ◽  
Circular Rnas ◽  
Farmed Fish ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific ◽  
Taxonomic Groups ◽  
And Function

Circular RNAs (circRNAs) are an emerging class of regulatory RNAs with a covalently closed-loop structure formed during pre-mRNA splicing. Recent advances in high-throughput RNA sequencing and circRNA-specific computational tools have driven the development of novel approaches to their identification and functional characterization. CircRNAs are stable, developmentally regulated, and show tissue- and cell-type-specific expression across different taxonomic groups. They play a crucial role in regulating various biological processes at post-transcriptional and translational levels. However, the involvement of circRNAs in fish immunity has only recently been recognized. There is also broad evidence in mammals that the timely expression of circRNAs in muscle plays an essential role in growth regulation but our understanding of their expression and function in teleosts is still very limited. Here, we discuss the available knowledge about circRNAs and their role in growth and immunity in vertebrates from a comparative perspective, with emphasis on cultured teleost fish. We expect that the interest in teleost circRNAs will increase substantially soon, and we propose that they may be used as biomarkers for selective breeding of farmed fish, thus contributing to the sustainability of the aquaculture sector.

scholarly journals Circular RNAs as Novel Diagnostic Biomarkers and Therapeutic Targets in Kidney Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianwen Yu ◽  
Danli Xie ◽  
Naya Huang ◽  
Qin Zhou
Keyword(s):  
Kidney Disease ◽  
Kidney Diseases ◽  
Expression Patterns ◽  
Therapeutic Targets ◽  
Kidney Injury ◽  
Renal Diseases ◽  
Circular Rnas ◽  
Specific Expression ◽  
Glomerular Diseases ◽  
Diagnosis And Prognosis

Circular RNAs (circRNAs) are a novel type of non-coding RNAs that have aroused growing attention in this decade. They are widely expressed in eukaryotes and generally have high stability owing to their special closed-loop structure. Many circRNAs are abundant, evolutionarily conserved, and exhibit cell-type-specific and tissue-specific expression patterns. Mounting evidence suggests that circRNAs have regulatory potency for gene expression by acting as microRNA sponges, interacting with proteins, regulating transcription, or directly undergoing translation. Dysregulated expression of circRNAs were found in many pathological conditions and contribute to the pathogenesis and progression of various disorders, including renal diseases. Recent studies have revealed that circRNAs may serve as novel reliable biomarkers for the diagnosis and prognosis prediction of multiple kidney diseases, such as renal cell carcinoma (RCC), acute kidney injury (AKI), diabetic kidney disease (DKD), and other glomerular diseases. Furthermore, circRNAs expressed by intrinsic kidney cells are shown to play a substantial role in kidney injury, mostly reported in DKD and RCC. Herein, we review the biogenesis and biological functions of circRNAs, and summarize their roles as promising biomarkers and therapeutic targets in common kidney diseases.

scholarly journals The complexity of alternative splicing and landscape of tissue-specific expression in lotus (Nelumbo nucifera) unveiled by Illumina- and single-molecule real-time-based RNA-sequencing

DNA Research ◽  
2019 ◽  
Vol 26 (4) ◽  
pp. 301-311 ◽  
Author(s):  
Yue Zhang ◽  
Tonny Maraga Nyong'A ◽  
Tao Shi ◽  
Pingfang Yang
Keyword(s):  
Alternative Splicing ◽  
Real Time ◽  
Single Molecule ◽  
Intron Retention ◽  
Critical Role ◽  
Full Length ◽  
Specific Expression ◽  
Splice Isoforms ◽  
Tissue Specific ◽  
Genomic Studies

Abstract Alternative splicing (AS) plays a critical role in regulating different physiological and developmental processes in eukaryotes, by dramatically increasing the diversity of the transcriptome and the proteome. However, the saturation and complexity of AS remain unclear in lotus due to its limitation of rare obtainment of full-length multiple-splice isoforms. In this study, we apply a hybrid assembly strategy by combining single-molecule real-time sequencing and Illumina RNA-seq to get a comprehensive insight into the lotus transcriptomic landscape. We identified 211,802 high-quality full-length non-chimeric reads, with 192,690 non-redundant isoforms, and updated the lotus reference gene model. Moreover, our analysis identified a total of 104,288 AS events from 16,543 genes, with alternative 3ʹ splice-site being the predominant model, following by intron retention. By exploring tissue datasets, 370 tissue-specific AS events were identified among 12 tissues. Both the tissue-specific genes and isoforms might play important roles in tissue or organ development, and are suitable for ‘ABCE’ model partly in floral tissues. A large number of AS events and isoform variants identified in our study enhance the understanding of transcriptional diversity in lotus, and provide valuable resource for further functional genomic studies.

scholarly journals Identification and Characterization of the Potential Promoter Regions of 1031 Kinds of Human Genes

2001 ◽  
Vol 11 (5) ◽  
pp. 677-684
Author(s):  
Yutaka Suzuki ◽  
Tatsuhiko Tsunoda ◽  
Jun Sese ◽  
Hirotoshi Taira ◽  
Junko Mizushima-Sugano ◽  
...  
Keyword(s):  
Large Scale ◽  
Expression Patterns ◽  
Cpg Islands ◽  
Genomic Sequences ◽  
Cdna Libraries ◽  
Promoter Regions ◽  
Specific Expression ◽  
Link Type ◽  
Potential Promoter ◽  
E Boxes

To understand the mechanism of transcriptional regulation, it is essential to identify and characterize the promoter, which is located proximal to the mRNA start site. To identify the promoters from the large volumes of genomic sequences, we used mRNA start sites determined by a large-scale sequencing of the cDNA libraries constructed by the “oligo-capping” method. We aligned the mRNA start sites with the genomic sequences and retrieved adjacent sequences as potential promoter regions (PPRs) for 1031 genes. The PPR sequences were searched to determine the frequencies of major promoter elements. Among 1031 PPRs, 329 (32%) contained TATA boxes, 872 (85%) contained initiators, 999 (97%) contained GC box, and 663 (64%) contained CAAT box. Furthermore, 493 (48%) PPRs were located in CpG islands. This frequency of CpG islands was reduced in TATA+/Inr+PPRs and in the PPRs of ubiquitously expressed genes. In the PPRs of the CGM2 gene, the DRA gene, and theTM30pl genes, which showed highly colon specific expression patterns, the consensus sequences of E boxes were commonly observed. The PPRs were also useful for exploring promoter SNPs.[The nucleotide sequences described in this paper have been deposited in the DDBJ, EMBL, and GenBank data libraries under accession nos.AU098358–AU100608.]

Expression Trapping: Identification of Novel Genes Expressed in Hematopoietic and Endothelial Lineages by Gene Trapping in ES Cells

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4622-4631 ◽  
Author(s):  
William L. Stanford ◽  
Georgina Caruana ◽  
Katherine A. Vallis ◽  
Maneesha Inamdar ◽  
Michihiro Hidaka ◽  
...  
Keyword(s):  
Large Scale ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Gene Trap ◽  
Novel Genes ◽  
Specific Expression ◽  
Blood Island

Abstract We have developed a large-scale, expression-based gene trap strategy to perform genome-wide functional analysis of the murine hematopoietic and vascular systems. Using two different gene trap vectors, we have isolated embryonic stem (ES) cell clones containing lacZreporter gene insertions in genes expressed in blood island and vascular cells, muscle, stromal cells, and unknown cell types. Of 79 clones demonstrating specific expression patterns, 49% and 16% were preferentially expressed in blood islands and/or the vasculature, respectively. The majority of ES clones that expressedlacZ in blood islands also expressed lacZ upon differentiation into hematopoietic cells on OP9 stromal layers. Importantly, the in vivo expression of the lacZ fusion products accurately recapitulated the observed in vitro expression patterns. Expression and sequence analysis of representative clones suggest that this approach will be useful for identifying and mutating novel genes expressed in the developing hematopoietic and vascular systems.

Expression Trapping: Identification of Novel Genes Expressed in Hematopoietic and Endothelial Lineages by Gene Trapping in ES Cells

Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4622-4631 ◽  
Author(s):  
William L. Stanford ◽  
Georgina Caruana ◽  
Katherine A. Vallis ◽  
Maneesha Inamdar ◽  
Michihiro Hidaka ◽  
...  
Keyword(s):  
Large Scale ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Gene Trap ◽  
Novel Genes ◽  
Specific Expression ◽  
Blood Island

We have developed a large-scale, expression-based gene trap strategy to perform genome-wide functional analysis of the murine hematopoietic and vascular systems. Using two different gene trap vectors, we have isolated embryonic stem (ES) cell clones containing lacZreporter gene insertions in genes expressed in blood island and vascular cells, muscle, stromal cells, and unknown cell types. Of 79 clones demonstrating specific expression patterns, 49% and 16% were preferentially expressed in blood islands and/or the vasculature, respectively. The majority of ES clones that expressedlacZ in blood islands also expressed lacZ upon differentiation into hematopoietic cells on OP9 stromal layers. Importantly, the in vivo expression of the lacZ fusion products accurately recapitulated the observed in vitro expression patterns. Expression and sequence analysis of representative clones suggest that this approach will be useful for identifying and mutating novel genes expressed in the developing hematopoietic and vascular systems.

Circular RNAs as biomarkers in liquid biopsy in colorectal cancer.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 230-230
Author(s):  
Manuel Valladares-Ayerbes ◽  
Carmen Garrigos ◽  
Miquel Taron ◽  
Angélica Figueroa ◽  
Enrique Aranda
Keyword(s):  
Colorectal Cancer ◽  
Bone Marrow ◽  
Expression Pattern ◽  
Liquid Biopsy ◽  
Expression Patterns ◽  
Target Prediction ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Blood Leukocytes ◽  
Specific Expression

230 Background: Circular RNAs (circRNAs) are emerging as essential regulators of cancer- related biological hallmarks, as cell proliferation, apoptosis, differentiation, immune regulation and angiogenesis. CircRNAs are abundant, conserved, and have a tissue‐specific expression pattern. These characteristics make them candidate to serve as biomarkers in liquid biopsy (LB) in cancer. The aim of this study is to analyse differential expression of circRNAs in the colorectal cancer (CRC) scenario. Methods: To comprehensively understand the expression patterns of circRNAs we characterized 13,617 circRNAs using a microarray [Arraystar v2 (8x15K)] in 10 human samples, five CRC cell lines, one colorectal human tumour, one normal colon healthy control, vs. Peripheral Human Blood Leukocytes (2 pools) and Human Bone Marrow. Differentially expressed circRNAs were identified using fold change (FC) cut-off or through Volcano Plot filtering respectively. CircRNAs having FC ▪2 and P-values ▪ 0.05 were selected. CircRNA/microRNA interaction was predicted with target prediction software. Results: Hierarchical clustering showed distinguishable circRNA expression profiling among 10 samples. These data indicated that circRNAs have a different expression pattern in colorectal tissues compared with that in blood and bone marrow tissues. The microarray data showed 2329 circRNAs differentially expressed (FC > 2.0, P < 0.05). Among them, 964 circRNAs were upregulated and 1365 were downregulated in colon tissues compared with blood and bone marrow. Using a stringent criterion (FC > 10, P≤ 0.01 and false discovery rate [FDR] < 0.05) we have identified 30 circRNA upregulated in colorectal cancer versus non tumour samples. CircRNA/microRNA interaction prediction analysis showed that most upregulated circRNAs contain miRNA Binding Sites (MREs) for cancer-related miRNA, including among others, miR-17, miR-103, miR-let-7g. Conclusions: Microarray analysis was used to comprehensively identify dysregulated circRNAs in CRC. We identify novel circRNAs could be valuable as blood-based CRC biomarkers.

scholarly journals Genome-wide identification and expression analysis of the CLC gene family in pomegranate (Punica granatum) reveals its roles in salt resistance

2020 ◽  
Author(s):  
Cuiyu Liu ◽  
Yujie Zhao ◽  
Xueqing Zhao ◽  
Jianmei Dong ◽  
Zhaohe Yuan
Keyword(s):  
Gene Family ◽  
Expression Patterns ◽  
Functional Characterization ◽  
Nitrogen Deficiency ◽  
Punica Granatum ◽  
Salt Resistance ◽  
Specific Expression ◽  
Multiple Sequence ◽  
Root Cells ◽  
Expression Levels

Abstract Backgrounds: Pomegranate (Punica granatum L.) is an important commercial fruit tree, with moderate tolerance to salinity. The balance of Cl− and other anions in pomegranate tissues are affected by salinity, however, the accumulation patterns of anions are poorly understood. The chloride channel (CLC) gene family is involved in conducting Cl−, NO3−, HCO3− and I−, but its characteristics have not been reported on pomegranate.Results: In this study, we identified seven PgCLC genes, consisting of four antiporters and three channels, based on the presence of the gating glutamate (E) and the proton glutamate (E). Phylogenetic analysis revealed that seven PgCLCs were divided into two clades, with clade I containing the typical conserved regions GxGIPE (I), GKxGPxxH (II) and PxxGxLF (III), whereas clade II not. Multiple sequence alignment revealed that PgCLC-B had a P [proline, Pro] residue in region I, which was suspected to be a NO3–/H+ exchanger, while PgCLC-C1, PgCLC-C2, PgCLC-D and PgCLC-G contained a S [serine, Ser] residue, with a high affinity to Cl−. We determined the content of Cl−, NO3−, H2PO4−, and SO42− in pomegranate tissues after 18 days of salt treatments (0, 100, 200 and 300 mM NaCl). Compared with control, the Cl− content increased sharply in pomegranate tissues. Salinity inhibited the uptake of NO3− and SO42− , but accelerated H2PO4− uptake. The results of real-time reverse transcription PCR (qRT-PCR) revealed that PgCLC genes had tissue-specific expression patterns. The high expression levels of three antiporters PgCLC-C1, PgCLC-C2 and PgCLC-D in leaves might be contributed to sequestrating Cl− into the vacuoles. However, the low expression levels of PgCLCs in roots might be associated with the exclusion of Cl− from root cells. Also, the up-regulated PgCLC-B in leaves indicated that more NO3− was transported into leaves to mitigate the nitrogen deficiency.Conclusions: Our findings suggested that the PgCLC genes played important roles in balancing of Cl− and NO3− in pomegranate tissues under salt stress. This study establishes a theoretical foundation for the further functional characterization of CLC genes in pomegranate.

scholarly journals A curated transcriptome dataset collection to investigate the functional programming of human hematopoietic cells in early life

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 414 ◽  
Author(s):  
Mahbuba Rahman ◽  
Sabri Boughorbel ◽  
Scott Presnell ◽  
Charlie Quinn ◽  
Chiara Cugno ◽  
...  
Keyword(s):  
Gene Expression ◽  
Early Life ◽  
Functional Programming ◽  
Web Application ◽  
Large Scale ◽  
Single Gene ◽  
Hematopoietic Cells ◽  
Biomedical Knowledge ◽  
Specific Expression ◽  
Age Related

Compendia of large-scale datasets made available in public repositories provide an opportunity to identify and fill gaps in biomedical knowledge. But first, these data need to be made readily accessible to research investigators for interpretation. Here we make available a collection of transcriptome datasets to investigate the functional programming of human hematopoietic cells in early life. Thirty two datasets were retrieved from the NCBI Gene Expression Omnibus (GEO) and loaded in a custom web application called the Gene Expression Browser (GXB), which was designed for interactive query and visualization of integrated large-scale data. Quality control checks were performed. Multiple sample groupings and gene rank lists were created allowing users to reveal age-related differences in transcriptome profiles, changes in the gene expression of neonatal hematopoietic cells to a variety of immune stimulators and modulators, as well as during cell differentiation. Available demographic, clinical, and cell phenotypic information can be overlaid with the gene expression data and used to sort samples. Web links to customized graphical views can be generated and subsequently inserted in manuscripts to report novel findings. GXB also enables browsing of a single gene across projects, thereby providing new perspectives on age- and developmental stage-specific expression of a given gene across the human hematopoietic system. This dataset collection is available at: http://developmentalimmunology.gxbsidra.org/dm3/geneBrowser/list.

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