ABSTRACT: Small RNAs were deep sequenced from the liver and spleen of adult mice in an effort to identify somatic piRNAs. Following sequencing of all small RNAs, known non-coding RNAs were computationally removed from the dataset. The remaining RNAs were then mapped to the genome and analyzed for sequence characteristics (5' base, length) typical of known piRNAs. To determine if any of the identified small RNAs were MIWI2 dependent, we deep sequenced small RNAs from liver and spleen of MIWI2 KO mice and analyzed them as above. We deep sequenced small RNAs from the liver and spleen of one WT mouse and one MIWI2 knock-out mouse. We then trimmed sequencing adapters and removed known ncRNAs (rRNA, tRNA, snoRNA, snRNA, miRNA) from the dataset before aligning reads to the mm9 assembly of the mouse genome.
Project description:Piwi-interacting RNAs are 25-32 nt small RNAs bound to Piwi proteins. To know the steps where factors involved in the piRNA biogenesis (MILI, MIWI2, ZUC (MitoPLD), MVH) work, we sequenced small RNAs from mutant mouse testes and analyzed piRNAs. Examination of small RNAs in testes of mutant mouse
Project description:Development of the early embryo is thought to be mainly driven by maternal gene products and post-transcriptional gene regulation. Here, we used metabolic labeling to show that RNA can be transferred by sperm into the embryo. To identify genes with paternal expression in the embryo, we performed crosses of males and females from divergent C. elegans strains. RNA sequencing of mRNAs and small RNAs in the 1-cell hybrid embryo revealed that about two hundred paternal mRNAs are reproducibly expressed in the embryo, and that about half of assayed endogenous siRNAs and piRNAs are also of paternal origin. Together, our results suggest an unexplored paternal contribution to early development. To reveal the identity of paternal RNA molecules, we performed a cross of males and females from two divergent C. elegans strains because we reasoned that sequencing of embryonic RNA and SNP analysis should then identify and quantify maternal and paternal transcripts. These sequencing experiments were carried out in purified hybrid 1-cell embryos and comprised small RNAs and mRNAs. For comparison we sequenced mRNAs and small RNAs from the parental strains: paternal (Hawaiian males, CB4856) and maternal (fem-1(hc17ts)/TX189(OMA-1::GFP). For the annotation of strain specific mutations (SNPs) we sequenced mRNA and small RNAs extracted from whole worms. All experiments were performed in at least two independent biological replicates.
Project description:Using a crucifer-infecting strain of Tobacco Mosaic Virus (TMV-Cg) and Arabidopsis thaliana as a model system, we analyzed the viral small RNA profile in wild-type plants as well as rdr mutants by applying small RNA deep sequencing technology. Over 100,000 TMV-Cg-specific small RNA reads, mostly of 21- (78.4%) and 22-nucleotide (12.9%) in size and originating predominately (79.9%) from the genomic sense RNA strand, were captured at an early infection stage, yielding the first high-resolution small RNA map for a plant virus. The TMV-Cg genome harbored multiple, highly reproducible small RNA-generating hot spots that corresponded to regions with no apparent local hairpin-forming capacity. Significantly, both the rdr1 and rdr6 mutants exhibited globally reduced levels of viral small RNA production as well as reduced strand bias in viral small RNA population, revealing an important role for these host RDRs in viral siRNA biogenesis. In addition, an informatics analysis showed that a large set of host genes could be potentially targeted by TMV-Cg-derived siRNAs for posttranscriptional silencing, raising the interesting possibility for a hidden layer of widespread virus-host interactions that may contribute to viral pathogenicity and host specificity. Profiling of TMV-Cg derived small RNAs in systemically infected tissues of wild type (Col-0) Arabidopsis as well as the rdr1and rdr6 mutants, at 3 days post-infection.
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 5’ 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 5’-tri-phosphate.
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. Small RNA associated with AGO2 of BmN cell infected with ie1-bacmid recombinant viruses were performed by high-throughput using Hiseq 2000.
Project description:Small RNAs play crucial roles in regulation of gene expression in many eukaryotes. Here, we report the cloning and characterization of 18-26 nt RNAs in the social amoeba Dictyostelium discoideum. This survey uncovered developmentally regulated microRNA candidates whose biogenesis, at least in one case, is dependent on a Dicer homolog, DrnB. Furthermore, we identified a large number of 21 nt RNAs originating from the DIRS-1 retrotransposon, clusters of which have been suggested to constitute centromeres. Small RNAs from another retrotransposon, Skipper, were significantly up-regulated in strains depleted of the second Dicer-like protein, DrnA, and a putative RNA-dependent RNA polymerase, RrpC. In contrast, the expression of DIRS-1 small RNAs was not altered in any of the analyzed strains. This suggests the presence of multiple RNAi pathways in D. discoideum. In addition, we isolated several small RNAs with antisense complementarity to mRNAs. Three of these mRNAs are developmentally regulated. Interestingly, all three corresponding genes express longer antisense RNAs from which the small RNAs may originate. In at least one case, the longer antisense RNA is complementary to the spliced but not the unspliced pre-mRNA, indicating synthesis by an RNA-dependent RNA polymerase. Keywords: cDNA library; small RNA sequencing The aim of this study was to investigate the small RNA (18-26 nt) profile of Dictyostelium discoideum during growth and development. For this reason, we cloned and sequenced pooled small RNAs from growing single cells and from two different multicellular stages (16 and 24 hours of development). cDNA libraries of 18-26 nt D. discoideum RNAs were constructed according to two different protocols (Lee, R.C. and Ambros, V. (2001) Science, 294; Lau, N.C. et al (2001) Science, 294). Briefly, total RNA was isolated from growing D. discoideum AX4 strain cells as well as from cells developed for 16 hours and 24 hours, and the fractions were subsequently pooled. After size fractionation and ligation of a 3’ linker, the RNA was divided into two fractions, one of which was directly ligated to a 5’ linker, thus selecting for small RNAs with 5’ monophosphates. Following RT-PCR, the PCR fragments were cloned and sequenced. The second fraction was subjected to reverse transcription directly after 3’ ligation. Apart from synthesizing a complementary DNA strand, the reverse transcriptase adds a few non-templated C residues at the 3’ end. These C:s were then hybridized to a DNA oligo with three 3’ G:s followed by RT-PCR, cloning and sequencing. This approach is insensitive of the nature of the 5’ end of the small RNA.
Project description:In order to identify new miRNAs, NAT-siRNAs and possibly abiotic-stress regulated small RNAs in rice, three small RNA libraries were constructed from control rice seedlings and seedlings exposed to drought or salt stress, and then subjected to pyrosequencing. Totally three sets of small RNAs, which were obtained under normal condition as well as salt and drought stress conditions
Project description:MicroRNAs and siRNAs are important regulators of plant development and seed formation, yet their population and abundance in the oil crop Brassica napus are still less understood, especially at different developmental stages and among cultivars with varied seed oil contents. Here, we systematically analyzed the small RNA expression profiles of Brassica napus seeds at early embryonic developmental stages in a high oil content and a low oil content Brassica napus cultivars, both cultured in two environments. A total of 50 conserved miRNAs and 11 new miRNAs were identified, together with some new miRNA targets. Expression analysis revealed some miRNAs with varied expression levels in different seed oil content cultivars or at different embryonic developmental stages. A large amount of 23-nt small RNAs with specific nucleotide composition preference were also identified, which may present new classes of functional small RNAs. Examination of small RNA profiles in 2 different seed oil content rapeseed culvitars at 2 locations.
Project description:Endogenous 24nt short interfering RNAs (siRNAs) derived mostly from intergenic and repetitive genomic regions constitute a major class of endogenous small RNAs in Arabidopsis thaliana. Accumulation of A. thaliana 24nt siRNAs requires the Dicer family member DCL3, and clear homologs of DCL3 exist in both flowering and non-flowering plants. However, the absence of a conspicuous 24nt peak in the total RNA populations of several non-flowering plants has raised the question of whether this class of siRNAs might, in contrast to the ancient 21nt microRNAs (miRNAs) and 21-22nt trans-acting siRNAs (tasiRNAs), be an angiosperm-specific innovation. Analysis of non-miRNA, non-tasiRNA hotspots of small RNA production within the genome of the moss Physcomitrella patens revealed multiple loci which consistently produced a mixture of 21-24nt siRNAs with a peak at 23nts. These Pp23SR loci were significantly enriched in transposon content, depleted in overlap with annotated genes, and typified by dense concentrations of the 5-methyl cytosine (5mC) DNA modification. Deep sequencing of small RNAs from two independent Ppdcl3 mutants showed that the P. patens DCL3 homolog is required for the accumulation of 22-24nt siRNAs, but not 21nt siRNAs, at Pp23SR loci. The 21nt component of Pp23SR-derived siRNAs was also unaffected by a mutation in the RNA-dependent RNA polymerase mutant Pprdr6. Transcriptome-wide, Ppdcl3 mutants specifically failed to accumulate 23 and 24nt small RNAs from repetitive regions. We conclude that intergenic/repeat-derived siRNAs are indeed a broadly conserved, distinct class of small regulatory RNAs within land plants. Our results also suggest that Pp DCL3 produces siRNAs of heterogenous size, unlike its A. thaliana homolog which generates exclusively 24nt siRNAs. Small RNAs from Wild-type (two technical replicates), rdr6-19 (two technical replicates), dcl3-5 (one sample), and dcl3-10 (one sample) were sequenced using a Solexa GA. Three different linkers were used for different samples and mixed prior to sequencing. linker 1: CTGTAGGCACCATCAAT (GPL7174 AND GSM313212, GSM313213) linker 2: CACTCGGGCACCAAGGA (GPL7175 AND GSM313214, GSM313215) linker 3: TTTAACCGCGAATTCCAG (GPL7176 AND GSM313216, GSM313217) Raw data: Two FASTQ files represent the raw data underlying the processed sample data in GSE12468. 080616_s_7_seq_GAK-2.fastq corresponds to GSM313212, GSM313214, and GSM313216. 080616_s_8_seq_GAK-3.fastq corresponds to GSM313213, GSM313215, and GSM313217. Experimentally, samples GSM313212, GSM313214, and GSM313216 (i.e., all three genotypes) were sequenced in the same run (hence the same FASTQ file). The sequencing run was a mixture of three different libraries with different linker sequences (as indicated above). These 'barcoded' samples were computationally extracted based on the linker sequences. This is also true for samples GSM313213, GSM313215, and GSM313217. Raw data were filtered to identify small RNAs associated with each linker. Subsequently, small RNAs were filtered to remove rRNA fragments. The remainder were mapped to the Physcomitrella patens draft genome version 1.2 (using oligomap) and filtered to retain only those with one or more perfect match. See Cho et al. for details.
Project description:PIWI proteins and their associated small RNAs called PIWI-interacting RNAs (piRNAs) restrict transposon activity in animal gonads to ensure fertility. Distinct biogenesis pathways load piRNAs into the PIWI proteins MILI and MIWI2 in the mouse male embryonic germline. While most of MILI piRNAs derive via a slicer-independent pathway, a MILI slicer endonuclease-initiated pathway loads nuclear MIWI2 with a series of phased piRNAs. Tudor domain-containing 12 (TDRD12) and its interaction partner Exonuclease domain-containing 1 (EXD1) are required for loading MIWI2, but only Tdrd12 is essential for fertility, leaving us with no explanation for the physiological role of Exd1. Using an artificial piRNA precursor, we demonstrate that MILI-triggered piRNA biogenesis is greatly reduced in the Exd1 mutant. The situation deteriorates in the sensitized Exd1 mutant (Exd1-/-; Tdrd12+/-), where diminished MIWI2 piRNA levels de-repress LINE1 retrotransposons, causing infertility. Thus, EXD1 enhances slicing-triggered MIWI2 piRNA biogenesis via a functional interaction with TDRD12. Overall design: Small RNA sequencing was used to identify differences in piRNA levels between various Exd1 and Tdrd12 mouse mutants. Total small RNAs were sequenced together with immunopurified MILI and MIWI2 associated piRNAs.