Project description:Compared to whole serum miRNAs, miRNAs in serum small extracellular vesicles (sEVs) are well protected form RNA enzymes, thus provide a consistent source of miRNA for disease biomarker detection. Serum sEVs and their miRNA cargos released by injured liver cells could be promising biomarkers for diagnosis of liver diseases. We were very interested to find out the effects of liver injury on serum extracellular vesicles as well as the small RNA components they transported, if there is any difference between acute and chronic injury. Study in this regard will help us to identify new serum biomarkers for liver injury, and to find out if there are specific markers for acute or chronic liver injury. To identify potential biomarker for liver injury based on serum sEVs miRNAs, we established the carbon tetrachloride (CCL4) induced acute and chronic liver injury mice model, and examined the dynamic changes of small RNA components, especially miRNAs, in serum sEVs.
Project description:Transcript leaders (TLs) can have profound effects on mRNA translation and stability. To map TL boundaries genome-wide, we developed TL-Sequencing (TL-Seq), a technique combining enzymatic capture of m7G-capped mRNA 5'-ends with high-throughput sequencing. TL-Seq identified mRNA start sites for the majority of yeast genes and revealed many examples of intragenic TL heterogeneity. Transcription initiation sites occur in at least 5% of protein-coding regions and are concentrated near the 5'ends of ORFs. These truncated mRNAs are translated, based on ribosome density analysis. Translation Associated TL-Seq (TATL-Seq), which combines TL-Seq with polysome fractionation, revealed substantial differences in translation of alternative TL isoforms. Globally, while some TL features are associated with poor translation and nonsense-mediated mRNA decay (uAUGs, very short length), others (secondary structure, long length) have much less impact than predicted from analyses of individual genes. TL-Seq and TATL-Seq can be applied to any eukaryote to investigate TL-mediated regulation of gene expression. TL-Seq (+/- pyrophosphatase), TATL-Seq (TL-Seq libraries from polysome gradient)
Project description:SMORE-seq (Simultaneous Mapping Of RNA Ends by sequencing) is developted to simultaneously identify the strongest TSS (Transcription Start Site) and PAS (Polyadenylation Site) SMORE-seq were performed in wild type Saccharomyces cerevisiae
Project description:The wide application of pig disease model has caused a surge of interest in the study of derivation of pig induced pluripotent cells (iPSCs). Here we performed genome-wide analysis of gene expression profiling by RNA-seq and small RNA-seq and DNA methylation profile by MeDIP-seq in pig iPSCs through comparison with somatic cells. We identified mRNA and microRNA transcripts that were specifically expressed in pig iPSCs. Our analysis identifies the genes up-regulated in pig iPS compared with somatic cells and also the differentially expressed genes between pig iPSCs under different culture medium. We then pursued comprehensive bioinformatics analyses, including functional annotation of the generated data within the context of biological pathways, to uncover novel biological functions associated with maintenance of pluripotency in pig. This result supports that pig iPS have transcript profiles linked to “ribosome”, “chromatin remodeling”, and genes involved in “cell cycle “that may be critical to maintain their pluripotency, plasticity, and stem cell function. Our analysis demonstrates the key role of RNA splicing in regulating the pluripotency phenotype of pig cells. Specifically, the data indicate distinctive expression patterns for SALL4 spliced variants in different pig cell types and highlight the necessity of defining the type of SALL4 when addressing the expression of this gene in pig cells. MeDIP-seq data revealed that the distribution patterns of methylation signals in pig iPS and somatic cells along the genome. We identify 25 novel porcine miRNA, including pluripotency-related miR-302/367cluster up-regulated in pig iPSCs. At last, we profile the dynamic gene expression signature of pluripotent genes in the preimplantation development embryo of pig. The resulting comprehensive data allowed us to compare various different subsets of pig pluripotent cell. This information provided by our analysis will ultimately advance the efforts at generating stable naïve pluripotency in pig cells.
Project description:The wide application of pig disease model has caused a surge of interest in the study ofderivation of pig induced pluripotent cells (iPSCs). Here we performed genome-wide analysis of gene expression profiling by RNA-seq and small RNA-seq and DNA methylation profile by MeDIP-seq in pig iPSCs through comparison with somatic cells. We identified mRNA and microRNA transcripts that were specifically expressed in pig iPSCs. Our analysis identifies the genes up-regulated in pig iPS compared with somatic cells and also the differentially expressed genes between pig iPSCs under different culture medium. We then pursued comprehensive bioinformatics analyses, including functional annotation of the generated data within the context of biological pathways, to uncover novel biological functions associated with maintenance of pluripotency in pig. This result supports that pig iPS have transcript profiles linked to M-bM-^@M-^\ribosomeM-bM-^@M-^], M-bM-^@M-^\chromatin remodelingM-bM-^@M-^], and genes involved in M-bM-^@M-^\cell cycle M-bM-^@M-^\that may be critical to maintain their pluripotency, plasticity, and stem cell function. Our analysis demonstrates the key role of RNA splicing in regulating the pluripotency phenotype of pig cells. Specifically, the data indicate distinctive expression patterns for SALL4 spliced variants in different pig cell types and highlight the necessity of defining the type of SALL4 when addressing the expression of this gene in pig cells. MeDIP-seq data revealed that the distribution patterns of methylation signals in pig iPS and somatic cells along the genome. We identify 25 novel porcine miRNA, including pluripotency-related miR-302/367cluster up-regulated in pig iPSCs. At last, we profile the dynamic gene expression signature of pluripotent genes in the preimplantation development embryo of pig. The resulting comprehensive data allowed us to compare various different subsets of pig pluripotent cell. This information provided by our analysis will ultimately advance the efforts at generating stable naM-CM-/ve pluripotency in pig cells.
Project description:Divergent transcription, in which reverse-oriented transcripts occur upstream of eukaryotic promoters in regions devoid of annotated genes, has been suggested to be a general property of active promoters. Here we show that the human basal RNA polymerase II transcriptional machinery and core promoter are inherently unidirectional, and that reverse-oriented transcripts originate from their own cognate reverse-directed core promoters. In vitro transcription analysis and mapping of nascent transcripts in cells revealed that core promoters are unidirectional and that sequences at reverse start sites are similar to those of their forward counterparts. The use of DNase I accessibility to define proximal promoter borders revealed that about half of promoters are unidirectional and that these unidirectional promoters are depleted at their upstream edges of reverse core promoter sequences and their associated chromatin features. Divergent transcription is thus not an inherent property of the transcription process, but rather the consequence of the presence of both forward- and reverse-directed core promoters. Using 5'-GRO-seq and GRO-seq to determine mechanisms of divergent transcription initiation
Project description:Small RNAs, including piRNAs, miRNAs and endogenous siRNAs, bind Argonaute proteins to form RNA-silencing complexes that target coding genes, transposons and aberrant RNAs. To assess the requirements for endogenous siRNA formation and activity in C. elegans, we developed a GFP-based sensor for the endogenous siRNA 22G siR-1, one of a set of abundant siRNAs processed from a precursor RNA mapping to the X chromosome, the X-cluster. Silencing of the sensor is also dependent on the partially complementary, unlinked 26G siR-O7 siRNA. We show that 26G siR-O7 acts in trans to initiate 22G siRNA formation from the X-cluster. The presence of several mispairs between 26G siR-O7 and the X-cluster mRNA, as well as mutagenesis of the siRNA sensor, indicates that siRNA target recognition is permissive to a degree of mispairing. From a candidate reverse genetic screen, we identified several factors required for 22G siR-1 activity, including the Argonaute ergo-1 and the 3' methyltransferase henn-1. Quantitative RT-PCR of small RNAs in a henn-1 mutant and deep sequencing of methylated small RNAs indicate that siRNAs and piRNAs that associate with PIWI clade Argonautes are methylated by HENN-1, while siRNAs and miRNAs that associate with non-PIWI clade Argonautes are not. Thus, PIWI-class Argonaute proteins are specifically adapted to associate with methylated small RNAs in C. elegans. This SuperSeries is composed of the following subset Series: GSE34320: Analysis of 22G siRNA triggered siRNA amplification in Caenorhabditis elegans GSE34321: Analysis of 3' 2'-O-methylated small RNAs in Caenorhabditis elegans Refer to individual Series
Project description:Gene expression in plastids of higher plants is dependent on two different transcription machineries, a plastid-encoded bacterial-type RNA polymerase (PEP) and a nuclear-encoded phage-type RNA polymerase (NEP), which recognize distinct types of promoters. The division of labor between PEP and NEP during plastid development and in mature chloroplasts is unclear due to a lack of comprehensive information on promoter usage. Here we present a thorough investigation into the distribution of PEP and NEP promoters within the plastid genome of barley (Hordeum vulgare L). Using a novel differential RNA sequencing approach, which discriminates between primary and processed transcripts, we obtained a genome-wide map of transcription start sites in plastids of mature first leaves. PEP-lacking plastids of the albostrians mutant allowed for the unambiguous identifications of NEP promoters. We observed that the chloroplast genome contains many more promoters than genes. According to our data, most genes (including genes coding for photosynthesis proteins) have both PEP and NEP promoters. We also detected numerous transcription start sites within operons indicating transcriptional uncoupling of genes in polycistronic gene clusters. Moreover, we mapped many transcription start sites in intergenic regions, as well as opposite to annotated genes demonstrating the existence of numerous non-coding RNA candidates. dRNA-seq analysis of total RNA from green and white plastids of the barley mutant line albostrians
Project description:MicroRNAs (miRNA), discovered in C. elegans, are short non-coding RNAs that bind and regulate the expression of target mRNAs in animals and plants. C. elegans miRNAs bind to partially complementary sequences in the 3' UTR of the target mRNA, which results in translational repression through mRNA destabilization. The high-throughput sequencing of RNA cleavage fragments was performed to directly detect cleaved miRNA targets in C. elegans. Based on this analysis, miR-249 was identified as a potential miRNA that regulates a ZK637.6 pseudogene, paralogous to asna-1 (ZK637.5), by a cleavage mechanism with extensive, evolutionary conserved complementarity. Additionally, we validated miR-249-directed cleavage of the ZK637.6 by a gene-specific 5M-bM-^@M-^Y rapid amplification of cDNA ends and observed notable difference in expression of ZK637.6 in wild-type versus mir-249 mutant C. elegans. Furthermore, phosphate-independent small-RNA sequencing analysis revealed that miR-249 target genes, including ZK637.6 pseudogene, showed 22G-RNA productions dependent on miR-249 targeting. These findings may lead to a better understanding of the biological roles of miRNAs for pseudogenes in C. elegans. Total small RNAs from wild-type and mir-249 mutant in adult stage worms were subjected to small RNA sequencing using an Illumina platform with Tobacco Acid Pyrophosphatase (TAP) treatment, allowing detection of secondary siRNAs carrying 5M-bM-^@M-^Y-tri-phosphate.