Project description:RNA-interference (RNAi) refers to a growing class of gene silencing phenomena defined by a requirement for small RNAs of 20-32 nt and the action of the Argonaute (Ago) family of ribonucleases. We have previously identified developmentally regulated small RNAs, using Northern blot analysis, that are expressed during X-chromosome inactivation in differentiating female mouse ES cels. We sought to identify these small RNAs using deep sequencing. We identified small RNAs that align to retrotransposon sequences and are enriched on the X-chromosome. LINE elements have been proposed to act as way stations during X-inactivation for the spreading of silencing along the entire chromosome, and our findings suggest that LINE elements found on the X-chromosome may be enriched for small RNAs relative to the genome. These results suggest that RNAi pathways are involved in regulating LINE elements during X-inactivation and ES cell differentiation.
Project description:RNA-interference (RNAi) refers to a growing class of gene silencing phenomena defined by a requirement for small RNAs of 20-32 nt and the action of the Argonaute (Ago) family of ribonucleases. We have previously identified developmentally regulated small RNAs, using Northern blot analysis, that are expressed during X-chromosome inactivation in differentiating female mouse ES cels. We sought to identify these small RNAs using deep sequencing. We identified small RNAs that align to retrotransposon sequences and are enriched on the X-chromosome. LINE elements have been proposed to act as way stations during X-inactivation for the spreading of silencing along the entire chromosome, and our findings suggest that LINE elements found on the X-chromosome may be enriched for small RNAs relative to the genome. These results suggest that RNAi pathways are involved in regulating LINE elements during X-inactivation and ES cell differentiation. We size-fractionated total RNA from differentiating female mouse ES cells (day 4) into 18-24 nt and 25-45 nt populations and sequenced each fraction separately using the 454 platform. We used a karyotypically stable 40XX female ES cell line (EL16.7) with one X each of 129 and M. castaneus origins: 129 x (M.castaneus x 129).
Project description:As important roles of small RNA pathways, AGO proteins mediate interaction of incorporated small RNAs with their targets. The resolution of AGO associated small RNAs showed a significant landscape of AGO proteins and their binding small RNAs. To characterize small RNAs that associated with BmAGO2 protein in Bombyx mori, the small RNA population associated with BmAGO2 in BmN cells was extracted from the AGO immunoprecipitated complex and the small RNAs between 17nt to 50nt separated by a polyacrylamide gel electrophoresis were subjected to library construction and deep sequencing.The high throughput sequencing yielded a total of 11691441 reads, representing 813,702 unique reads with a abundance from 5731905 to 1.
Project description:To address the role of small regulatory RNAs in rice development, we generated a large data set of small RNAs from root apices (RoApx), shoot apices (ShApx), developing inflorescence (Infl) and mature leaf (Leaf). These tissues were chosen because they are expected to be rich in small RNAs and display different patterns of small RNA expression. The RoApx, ShApx, and Infl samples are expected to be enriched for meristematic tissues each of which have different fates. The Infl sample would also be expected to contain developing female gametes. In contrast, the Leaf sample is terminally differentiated and may be expected to be more transcriptionally repressed. These small RNAs comprise a total of 781,885 distinct sequences, and all of these map to at least one locus of the rice genome TIGR version 5.
Project description:Piwi-related Argonaute proteins play important roles in maintaining germline integrity and fertility and have been linked to a class of germline-enriched small RNAs termed piRNAs. Caenorhabditis elegans encodes two Piwi family proteins called PRG-1 and PRG-2, and PRG-1 interacts with the C. elegans piRNAs (21U-RNAs). Previous studies found that the prg-1 mutation causes a marked reduction in the expression of 21U-RNAs, temperature-sensitive defects in fertility and other phenotypic defects.To systematically demonstrate the function of PRG-1 on regulating small RNAs and their targets. We use recent advances in high-throughput sequencing technology to show that expression of non-coding small RNAs in six stages(embryo,L1,L2,L3,L4,young audlt) and mRNAs in four stages (L1,L2,L3,L4) after prg-1 mutation. prg-1 mutation can not only lead to a decrease in the expression of 21U-RNAs, but also cause 35~40% of miRNAs to be significantly down-regulated; approximately 3% (6.00% in L4) of protein-coding genes are differentially expressed after mutating prg-1, and 60~70% of these substantially changed protein-coding genes are up-regulated.
Project description:High-throughput sequencing of endogenous small RNAs from the moss Physcomitrella patens. This dataset encompasses microRNAs and other small RNAs of ~20-24 nucleotides expressed in the moss P. patens. SAMPLES UPDATED JULY 9, 2007 TO INCLUDE DATA ON SEQUENCED SMALL RNAS THAT DO NOT MATCH THE P. PATENS GENOME Keywords: High throughput small RNA sequencing