Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “RNA sequencing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources

The vertebrate 7S K RNA separates hagfish (Myxine glutinosa) and lamprey (Lampetra fluviatilis).

7S RNA sequences from the hagfish (Myxiniformes) and lamprey (Petromyzontiformes) were cloned and analyzed. In both species, 7S L RNA (also designated SRP RNA, since it represents the RNA constituent of the signal recognition particle) was clearly detectable. The sequence similarity between the two species was 86%, compared with about 75% similarity between either of these species and mammals. 7S K RNA was also cloned from the lamprey. The similarity between the 7S K RNA of the lamprey and that of mammals was 68%. Interestingly, several interspersed elements were found with nearly 100% similarity compared with mammals. In contrast to the lamprey, no 7S K RNA-related sequences were detectable among hagfish RNA, neither in northern blots nor with the PCR assay. In view of the significant conservation between the 7S K RNA of lamprey and that of mammals (human), this unexpected result clearly separates lamprey and hagfish. In addition, the lack of detectable 7S K RNA sequences in an outgroup, such as amphioxus, indicates that these results do not reflect an autapomorphy of hagfish. Therefore, our data provide additional support to the notion of a sister group relationship between Petromyzontiformes and gnathostomous vertebrates to the exclusion of Myxiniformes.

Animals↗

3'-Terminal nucleotide sequence of alfalfa mosaic virus RNA 4.

The sequence of the 3'-terminal 91 nucleotides of alfalfa mosaic virus RNA 4, the messenger for the viral coat protein, has been elucidated. A fragment containing the 3' terminus of the RNA was obtained by mild digestion with RNase T1. The primary structure of the fragment was deduced by labeling it in vitro at its 5' terminus and application of RNA sequencing techniques. The sequence is completely extracistronic and is believed to contain the binding sites for the viral coat protein and replicase.

Base Sequence↗

GBMdeconvoluteR accurately infers proportions of neoplastic and immune cell populations from bulk glioblastoma transcriptomics data.

BACKGROUND: Characterizing and quantifying cell types within glioblastoma (GBM) tumors at scale will facilitate a better understanding of the association between the cellular landscape and tumor phenotypes or clinical correlates. We aimed to develop a tool that deconvolutes immune and neoplastic cells within the GBM tumor microenvironment from bulk RNA sequencing data. METHODS: We developed an IDH wild-type (IDHwt) GBM-specific single immune cell reference consisting of B cells, T-cells, NK-cells, microglia, tumor associated macrophages, monocytes, mast and DC cells. We used this alongside an existing neoplastic single cell-type reference for astrocyte-like, oligodendrocyte- and neuronal progenitor-like and mesenchymal GBM cancer cells to create both marker and gene signature matrix-based deconvolution tools. We applied single-cell resolution imaging mass cytometry (IMC) to ten IDHwt GBM samples, five paired primary and recurrent tumors, to determine which deconvolution approach performed best. RESULTS: Marker-based deconvolution using GBM-tissue specific markers was most accurate for both immune cells and cancer cells, so we packaged this approach as GBMdeconvoluteR. We applied GBMdeconvoluteR to bulk GBM RNAseq data from The Cancer Genome Atlas and recapitulated recent findings from multi-omics single cell studies with regards associations between mesenchymal GBM cancer cells and both lymphoid and myeloid cells. Furthermore, we expanded upon this to show that these associations are stronger in patients with worse prognosis. CONCLUSIONS: GBMdeconvoluteR accurately quantifies immune and neoplastic cell proportions in IDHwt GBM bulk RNA sequencing data and is accessible here: https://gbmdeconvoluter.leeds.ac.uk.

Humans↗

The stability of bacteriophage T4 gene 32 mRNA: a 5' leader sequence that can stabilize mRNA transcripts.

In T4-infected cells, the gene 32 monocistronic mRNA is very stable. To study the molecular basis for this stability, we have constructed chimeric plasmids containing the monocistronic promoter and the gene 32 translation initiation sequence fused to either most of the E. coli lac operon or only a segment of the lacZ gene, followed by the gene 32 transcription terminator. The resulting hybrid transcripts are unstable in uninfected cells. In phage-infected cells, however, the hybrid mRNAs are at least as stable as gene 32 mRNA itself. Analysis of other plasmid constructs indicates that the sequences on the gene 32 mRNA from its 5' end to slightly beyond the initiation codon suffice to stabilize these hybrids. Studies with a series of deletions of the gene 32 leader sequence suggest that an RNA sequence near the gene 32 initiation codon is involved. Various models to explain this mRNA stabilization are discussed.

DNA Helicases↗

Molecular phylogeny of the animal kingdom.

A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.

Animals↗

Sequence relationships between Kirsten retrovirus genomes and the genomes of other murine retroviruses.

RNA sequence relationships between the genomes of the Kirsten murine sarcoma virus (MSV-K) complex, the Kirsten murine leukemia virus (MuLV-K) complex, the Gross murine leukemia virus (MuLV-G), and the Moloney murine leukemia virus (MuLV-M) were investigated. Sedimentation analyses revealed the expected 30 and 34 S RNA subunits in the MSV-K complex and a previously undetected 30 S RNA subunit accompanying the 34 S RNA subunit in the MuLV-K complex. Nucleic acid hybridization data indicated that each Kirsten virus 30 S RNA subunit had about 40% sequence homology with the RNA genome of MuLV-G, although these sequences were only partially homologous between the two 30 S subunits. In contrast, the MuLV-K 34 S RNA subunit had 96% sequence homology with the MuLV-G genome, whereas the MSV-K 34 S RNA subunit displayed only 71% sequence homology with the MuLV-G genome. Similar relationships were indicated by oligonucleotide fingerprinting. The oligonucleotide data, taken with published sequence data on the MuLV-G and MuLV-M genomes, enabled us to construct partial sequence maps of the MuLV-K 34 S RNA subunit and the MSV-K 34 and 30 S RNA subunits. The sequence arrangements indicated that (1) the MuLV-K 34 S RNA subunit is a variant of the MuLV-G genome; (2) the MSV-K 34 S RNA subunit is a recombinant molecule, which maintains the length of its leukemia virus parent; and (3) the MSV-K 30 S RNA subunit may have been generated from the MuLV-K 34 S genome by a two-stage process, culminating in the retention of parental sequences only within the U5 and U3 noncoding segments and within several amino-terminal coding segments. Further examination of published retrovirus genome sequences revealed several strategically situated sets of potential recognition signals for transcription and translation and suggested a model for genetic recombination based on mRNA splicing signals and areas of limited sequence homology. This model may explain how foreign gene elements can be inserted into retrovirus genomes to generate either functional or defective recombinant retroviruses.

AKR murine leukemia virus↗

Alfalfa mosaic virus RNA. Determination of the sequence homology between the four RNA species and a comparison with the four RNA species of cucumber mosaic virus.

The method of Taylor et al. [Taylor, J. M., Illmensee, R & Summers, J. (1976) Biochim. Biophys. Acta, 442, 324--330 and Gould and Symons (1977) Nucleic Acids Res. 4, 3787--3802] has been used to transcribe complementary DNA probes from the four major RNAs of alfalfa mosaic virus (AMV). Analysis of the kinetics of hybridization of these probes in homologous and heterologous complementary DNA . RNA hybridization reactions has shown that the sequence of the smallest RNA (RNA 4), which contains the coat protein gene, is present within RNA 3 and located at the 3' end of this RNA species. RNAs 1 and 2 are unique RNA molecules with little or no sequence homology between them or RNAs 3 and 4. This latter observation contrasts with the situation that occurs in cucumber mosaic virus (CMV) as CMV RNAs 1--4 were shown to have a common nucleotide stretch of 200 bases at their 3' termini; the location of RNA 4 within RNA 3 of CMV was also shown to be at the 3' end of this RNA species.

Avian Myeloblastosis Virus↗

Genomic characteristics and prognostic correlations in Chinese multiple myeloma patients.

BACKGROUND: Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of abnormal clonal plasma cells in the bone marrow. The heterogeneity in Chinese MM populations remains underexplored. METHODS: We conducted whole-exome sequencing (WES) on 241 tumor samples, complemented by RNA sequencing (RNA-seq) on 131 samples from 212 Chinese MM patients. RESULTS: We identified a novel mutational signature and analyzed molecular differences between newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM) patients. NFKBIA mutations were notably more frequent in NDMM patients compared to the MMRF-COMMPASS cohort (4/50 vs 22/937, p = 0.048), with additional recurrent mutations in several genes like TTN, IGLL5 and SYNE1. In RRMM patients, UBR5 mutations were more prevalent (4/24 vs 0/50, p = 0.01), alongside frequent mutations in OBSCN, CACNA1H, and HSPG2. Clonal evolution was assessed through multiple time points and locations, identifying genes potentially linked to circulating plasma cell formation. Cox regression analysis revealed that age and mutations in OBSCN and RB1 were significant predictors of progression-free survival (PFS) in NDMM patients. Additionally, albumin, β2-microglobulin, and RB1 mutations were correlated with overall survival (OS). CONCLUSIONS: In summary, we characterized the genomic landscape of MM in diverse Chinese populations, confirmed clonal evolution, and identified prognostic genes.

Adult↗

Balancing LncRNA H19 and miR-675 Bioconversion as a Key Regulator of Embryonic Myogenesis Under Maternal Obesity.

BACKGROUND: Maternal obesity (MO) impairs fetal skeletal muscle development, but the underlying mechanisms remain poorly defined. The regulatory roles of lncRNA H19 and its first exon derived microRNA675 (miR675) in prenatal muscle development remain to be examined. H19/Igf2 are in the same imprinting cluster with H19 expressed from the maternal allele while Igf2 expresses paternally. H19 contains a G-rich loop, and KH-type splicing regulatory protein (KHSRP) mediates the biogenesis of pre-miRNAs containing G-rich loops, which depends on its phosphorylation by AKT, a key mediator of IGF2 signalling. This study aims to depict the elusive function of these regulators that are affected by MO during embryonic myogenesis. METHODS: Single-cell transcriptomic sequencing and GeoMx spatial RNA sequencing were performed to identify the differentially expressed genes between embryos from MO and control (CT) mice. Both E11.5 and E13.5 embryos were collected and analysed to validate the sequencing data. The roles of H19 and miR657 in myogenesis were further analysed in P19 embryonic cells via CRISPR/dCas9-mediated H19 activation and inhibition. The epigenetic changes of H19 were analysed by methylated DNA immunoprecipitation, and allele-targeted analysis of H19 was performed by crossing C57BL/6J and CAST/EiJ mice. RESULTS: Transcriptomic analysis showed that MO embryos contained less differentiated myocytes (1.34%) than CT embryos (2.86%). Myogenesis-related GO biological processes were down-regulated in the MO embryonic myotome region. MO embryos showed lower expression of myogenic transcription factors such as Myf5, Myod1, Myog, Mef2c and Myh3 (p&#x2009;<&#x2009;0.05). MO altered epigenetic modifications of the H19 genomic cluster, showing a decreased methylation level in H19 imprinting control region (p&#x2009;<&#x2009;0.05) and a diallelic expression pattern of H19, which elevated its expression in MO embryos. Overexpression of H19 inhibited myogenesis in P19 cells, but miR675 promoted myogenesis, suggesting the critical regulatory roles of bioconversion of H19 to miR675. A KHSRP mediates the biogenesis of miR675, a process that relies on its phosphorylation by IGF2/AKT signalling. Knocking-down of KHSRP and inhibition of AKT abolished miR675 biogenesis. MO suppressed IGF2/AKT signalling and blocked KHSRP-dependent miR675 biogenesis in embryos. CONCLUSIONS: We found differential effects of H19 and miR675 on embryonic myogenesis. MO up-regulates H19 but blocks its miR675 bioconversion via suppressing IGF2/AKT/KHSRP signalling axis. Myogenesis in MO embryos was impeded due to the highly accumulated H19 and blocked miR675 biogenesis.

RNA, Long Noncoding↗

Site-specific cleavage of RNA by Fe(II).bleomycin.

Bleomycin is an antitumor agent whose activity has long been thought to derive from its ability to degrade DNA. Recent findings suggest that cellular RNA may be a therapeutically relevant locus. At micromolar concentrations, Fe(II)-bleomycin readily cleaved a Bacillus subtilis tRNAHis precursor in a highly selective fashion, but Escherichia coli tRNA(Tyr) precursor was largely unaffected even under more forcing conditions. Other substrates included an RNA transcript encoding a large segment of the reverse transcriptase from human immunodeficiency virus 1. RNA cleavage was oxidative, approximately 10-fold more selective than DNA cleavage, and largely unaffected by nonsubstrate RNAs. RNA sequence analysis suggested recognition of RNA tertiary structure, rather than recognition of specific sequences; subsets of nucleotides at the junction of single- and double-stranded regions were especially susceptible to cleavage. The ready accessibility of cellular RNAs to xenobiotic agents, the high selectivity of bleomycin action on RNAs, and the paucity of mechanisms for RNA repair suggest that RNA may be a therapeutically relevant target for bleomycin.

Bacillus subtilis↗

Infrequency of detection of particle-associated MSRV/HERV-W RNA in the synovial fluid of patients with rheumatoid arthritis.

OBJECTIVES: To determine whether the recently identified multiple sclerosis-associated retrovirus, MSRV, is detectable in the serum and synovial fluid of patients with rheumatoid arthritis (RA). METHODS: A reverse transcription-polymerase chain reaction (RT-PCR) assay was used to seek evidence of particle-associated MSRV/HERV-W RNA in the plasma and synovial fluid of patients with RA and controls. Stringent precautions were taken to avoid detection of contaminating human genomic DNA and cellular RNA sequences. RESULTS: Thirty-seven plasma samples were tested (20 from RA patients and 17 from controls) but none had detectable MSRV/HERV-W RNA. Synovial fluid samples were available from nine patients with RA and 10 controls. Particle-associated MSRV/HERV-W RNA was reproducibly detected in two of nine synovial fluid samples from RA patients and in one control sample. The identity of RT-PCR products was confirmed by sequencing. CONCLUSION: MSRV/HERV-W RNA sequences are detectable in the synovial fluid of a small proportion of RA patients, but this phenomenon may not be specific to RA.

Arthritis, Rheumatoid↗

LINNAEUS: Simultaneous Single-Cell Lineage Tracing and Cell Type Identification.

A key goal of biology is to understand the origin of the many cell types that can be observed during diverse processes such as development, regeneration, and disease. Single-cell RNA-sequencing (scRNA-seq) is commonly used to identify cell types in a tissue or organ. However, organizing the resulting taxonomy of cell types into lineage trees to understand the origins of cell states and relationships between cells remains challenging. Here we present LINNAEUS (Spanjaard et al, Nat Biotechnol 36:469-473. https://doi.org/10.1038/nbt.4124 , 2018; Hu et al, Nat Genet 54:1227-1237. https://doi.org/10.1038/s41588-022-01129-5 , 2022) (LINeage tracing by Nuclease-Activated Editing of Ubiquitous Sequences)-a strategy for simultaneous lineage tracing and transcriptome profiling in thousands of single cells. By combining scRNA-seq with computational analysis of lineage barcodes, generated by genome editing of transgenic reporter genes, LINNAEUS can be used to reconstruct organism-wide single-cell lineage trees. LINNAEUS provides a systematic approach for tracing the origin of novel cell types, or known cell types under different conditions.

Single-Cell Analysis↗

An investigation of the binding sites of proteins S8, L23 and L24 on the ribosomal RNAs of Escherichia coli by electron microscopy.

An electron microscopic method was used to investigate the binding regions of proteins S8 on 16S RNA, and proteins L23 and L24 on 23S RNA. Regions of the RNA that were not stabilised by the protein were completely denatured in 80% dimethyl-sulfoxide. The lengths of these denatured RNA regions were compared with that of the whole denatured RNA. Conclusions are drawn concerning the approximate location of the three proteins and these results are correlated with both RNA structural data and RNA sequence data on the RNA binding regions of the proteins.

Bacterial Proteins↗