Project description:We use small RNA sequencing to look for spreading of secondary and tertiary siRNAs along transcripts targeted by ectopic hairpin-derived primary siRNAs. We find that signals within the 3' UTR inhibit siRNA spreading. sequencing of 20-30nt sRNAs from Argonaute immunoprecipitation
Project description:We analyzed the small RNAs bound to the fission yeast RITS and ARC complexes, and to Ago1 in wild-type and ARC mutant cells, to gain insight into the molecular role of ARC. We found that ARC contains longer heterochromatic siRNAs than RITS, and that ARC subunit Arb1 is required for loading small RNAs onto Ago1. Sequencing of 18-28 nt small RNAs from Tas3, Arb1 and Ago1 purifications.
Project description:We tested whether we could increase the population of Rdp1-independent primary siRNAs in fission yeast by overexpressing the Dcr1 ribonuclease. We found that in addition to generation of centromeric siRNAs, which was expected, Dcr1 overexpression also resulted in generation of genome-wide primary siRNAs, mapping to many open reading frames. sequencing of 20-30nt sRNAs from total RNA
Project description:By surveying miRNA populations in each sex, we identified sets of miRNAs differentially expressed in male and female tissues across various stages of development. Small RNAs cloning of dissected male and female tissues from Drosophila melanogaster at various stages
Project description:We report that rice endosperm shows a specific hypomethylation of DNA in the maternal genome, preferring regions of high DNA accessibility. Maternally expressed imprinted genes are enriched for hypomethylation at putative promoter regions and transcriptional termini, and paternally expressed genes at promoters and gene bodies, mirroring our recent results in A. thaliana. However, unlike in A. thaliana, rice endosperm sRNA populations are dominated by specific strong sRNA-producing loci, and imprinted 24-nt sRNAs are expressed from both parental genomes and correlate with hypomethylation. Overlaps between imprinted sRNA loci and imprinted genes expressed from opposite alleles suggest that sRNAs may regulate genomic imprinting. Whereas sRNAs in seedling tissues primarily originate from small Class II (cut and paste) transposable elements, those in endosperm are much more uniformly derived, including sequences from other TE classes, as well as genic and intergenic regions. Our data indicate that the endosperm exhibits a unique pattern of sRNA expression and suggest that demethylation of maternal endosperm DNA is conserved in flowering plants. Examination of DNA methylation and small RNA expression in the seeds of two cultivars from the japonica subspecies of Oryza sativa L.
Project description:microRNAs (miRNAs) are a class of small silencing RNAs that have regulatory roles in gene expression. miRNAs interact with Argonaute (AGO) proteins to form effector complexes that can cleave target mRNAs or repress their translation. Rice encodes four AGO1 homologs (AGO1a, AGO1b, AGO1c, and AGO1d). We used an RNAi approach to knock down the four AGO1s. The RNAi lines displayed pleiotropic developmental phenotypes and had increased accumulation of miRNA targets, suggesting the involvement of AGO1s in the miRNA pathway. Three of the AGO1s (AGO1a, AGO1b, and AGO1c complexes) were purified and further characterized. We showed that the three AGO1s all have a strong preference for binding small RNAs (sRNAs) with 5’ U and have Slicer activity. We catalogued the sRNAs in each AGO1 complex by deep sequencing, and found all three AGO1s predominantly bound known miRNAs. Most of the miRNAs were evenly distributed in the three AGO1 complexes, suggesting a redundant role for the AGO1s in the function of these miRNAs. Intriguingly, we also found a subset of miRNAs were specifically incorporated into or excluded from one of the AGO1s, suggesting that there is also functional specialization among the rice AGO1s. Four samples, total extract and three AGO1 complexes were analyzed
Project description:modENCODE_submission_2744 This submission comes from a modENCODE project of Eric Lai. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We plan to generate a comprehensive catalog of expressed and functional microRNAs, and generate biological evidence for their regulatory activity. We plan also to delineate the primary transcription units of microRNA genes. Finally, we plan to annotate other classes of non-miRNA expressed small RNAs, as least some of which may define novel classes of small RNA genes. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Keywords: RIP-seq EXPERIMENT TYPE: RIP-seq. BIOLOGICAL SOURCE: Strain: Canton S; Developmental Stage: Adult Female; Genotype: wild type; Sex: Female; EXPERIMENTAL FACTORS: Adult_ovaries
Project description:modENCODE_submission_2746 This submission comes from a modENCODE project of Eric Lai. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We plan to generate a comprehensive catalog of expressed and functional microRNAs, and generate biological evidence for their regulatory activity. We plan also to delineate the primary transcription units of microRNA genes. Finally, we plan to annotate other classes of non-miRNA expressed small RNAs, as least some of which may define novel classes of small RNA genes. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Keywords: RIP-seq EXPERIMENT TYPE: RIP-seq. BIOLOGICAL SOURCE: Strain: Ago2 414; Developmental Stage: Adult Female; Genotype: w;;ago2[414]; Sex: Female; EXPERIMENTAL FACTORS: Adult_ovaries
Project description:modENCODE_submission_2749 This submission comes from a modENCODE project of Eric Lai. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We plan to generate a comprehensive catalog of expressed and functional microRNAs, and generate biological evidence for their regulatory activity. We plan also to delineate the primary transcription units of microRNA genes. Finally, we plan to annotate other classes of non-miRNA expressed small RNAs, as least some of which may define novel classes of small RNA genes. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Keywords: RIP-seq EXPERIMENT TYPE: RIP-seq. BIOLOGICAL SOURCE: Strain: r2d2 1; Developmental Stage: Adult Female; Genotype: w; r2d2[1]; Sb/TM6B; Sex: Female; EXPERIMENTAL FACTORS: Adult_ovaries
Project description:modENCODE_submission_2833 This submission comes from a modENCODE project of Eric Lai. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We plan to generate a comprehensive catalog of expressed and functional microRNAs, and generate biological evidence for their regulatory activity. We plan also to delineate the primary transcription units of microRNA genes. Finally, we plan to annotate other classes of non-miRNA expressed small RNAs, as least some of which may define novel classes of small RNA genes. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Keywords: RIP-seq EXPERIMENT TYPE: RIP-seq. BIOLOGICAL SOURCE: Strain: Dcr-2L811fsX; Developmental Stage: Adult Female; Genotype: Dcr-2[L811fsX]; Sex: Female; EXPERIMENTAL FACTORS: Adult_ovaries