Small RNA sequencing study of the nematode phylum
Ontology highlight
ABSTRACT:
ORGANISM(S): Hypsibius dujardini
SUBMITTER: Peter Sarkies
PROVIDER: E-GEOD-56651 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Comparison of small RNAs between virus-infected animals and their progeny Sequencing of small RNAs (15-30nt)
2015-01-01 | E-GEOD-60020 | biostudies-arrayexpress
Project description:Identification of defects in piRNAs and piRNA precursors Sequencing of small RNAs (18-30nt). Sample treatments: Secondary siRNAs in C. elegans carry a 5' triphosphate and this has to be removed prior to cloning, hence the use of 5' polyphosphatase treatment to reveal this population. TAP (tobacco acid pyrophosphatase) is another enzyme that removes 5' triphosphate but it also removes 5' CAP structures- we used this to look for piRNA precursor sequences in C. elegans that have a 5' cap.
2014-04-01 | E-GEOD-49220 | biostudies-arrayexpress
Project description:In the nematode Caenorhabditis elegans, different small RNA-dependent gene silencing mechanisms act in the germline to initiate transgenerational gene silencing. Piwi-interacting RNAs (piRNAs) can initiate transposon and gene silencing by acting upstream of endogenous short interfering RNAs (siRNAs), which engage a nuclear RNA interference (RNAi) pathway to trigger transcriptional gene silencing. Once gene silencing has been established, it can be stably maintained over multiple generations without the requirement of the initial trigger and is also referred to as RNAe or paramutation. This heritable silencing depends on the integrity of the nuclear RNAi pathway. However, the exact mechanism by which silencing is maintained across generations is not understood.Here we demonstrate that silencing of piRNA targets involves the production of two distinct classes of small RNAs with different genetic requirements. The first class, secondary siRNAs, are localized close to the direct target site for piRNAs. Nuclear import of the secondary siRNAs by the Argonaute HRDE-1 leads to the production of a distinct class of small RNAs that map throughout the transcript, which we term tertiary siRNAs. Both classes of small RNAs are necessary for full repression of the target gene and can be maintained independently of the initial piRNA trigger. Consistently, we observed a form of paramutation associated with tertiary siRNAs. Once paramutated, a tertiary siRNA generating allele confers dominant silencing in the progeny regardless of its own transmission, suggesting germline-transmitted siRNAs are sufficient for multigenerational silencing. C. elegans strains containing transgenes silenced by piRNAs were crossed to strains with transgenes with similar sequences but without piRNA target sites, to investigate the spreading of silencing between transgenes mediated by small RNAs. Mutant backgrounds were used to investigate the genetic requirements for this process.
2015-04-01 | E-GEOD-66344 | biostudies-arrayexpress
Project description:Dissection of the small RNA pathway required for generation of an antiviral small RNA response Small non-coding RNA (~15-30nt) was extracted from animals infected with the Orsay virus
2013-06-01 | E-GEOD-41693 | biostudies-arrayexpress
Project description:Small non-coding RNAs (sncRNAs) have been proposed as potential vectors of the interface between genes and environment. Here, we report that environmental conditions involving traumatic stress in early life, alter miRNA and piRNA composition in sperm of adult males in mice. Examination of small RNA content of sperm from males, that experienced early chronic stress during their first two weeks of life versus small RNA content of sperm from control males.
2014-04-13 | E-GEOD-50132 | biostudies-arrayexpress
Project description:Small RNA sequencing shows that there are no Caenorhabditis elegans endo siRNAs made against the OxyS non-coding RNA. Sequencing of small RNAs from C. elegans fed bacteria overexpressing the non-coding RNA OxyS, control samples fed either standard E. coli or one without the OxyS RNA, an rde-4 deletion mutant deficient in endo siRNA production and the OxyS-overexpressing bacteria itself. 5' independent samples were treated with the enzyme RNA 5' polyphosphatase to remove 5' triphosphate; 5' dependent samples were not treated with 5' polyphosphatase.
2016-07-05 | E-GEOD-64990 | biostudies-arrayexpress
Project description:Salivary glands or larval ovaries were isolated from transgenic flies expressing RNAi targeting Nautilus (control) or linker histone H1 using a Tub-Gal4 driver. ~200 larvae were used to isolate salivary glands or ovaries, independently. Total RNA was isolated using Trizol reagent following manufacturer's guidelines. Then 5 M-BM-5g of total RNA was separated on a polyacrylamide gel, and 18-29 nt small RNAs were isolated for cloning.
2013-04-22 | E-GEOD-44399 | biostudies-arrayexpress
Project description:In animals, a discrete class of small RNAs, the piwi-interacting RNAs (piRNAs), guard germ cell genomes against the activity of mobile genetic elements. piRNAs are generated, via an unknown mechanism, from apparently single-stranded precursors that arise from discrete genomic loci, termed piRNA clusters. The content of piRNA clusters, determines the capacity of the system to respond to a given element, in essence comprising an organism's evolving molecular definition of transposons. Presently, little is known about the signals that distinguish a locus as a source of piRNAs and about how abundant piRNAs are selected. To address these questions, we inserted new sequence information into piRNA clusters in mice and flies. In all cases, this information was incorporated into the piRNA repertoire and in one instance was shown to confer the ability to recognize and silence a corresponding element. Notably, patterns of piRNA abundance suggested that both intrinsic sequence and context with the cluster inform piRNA generation. Though piRNAs themselves are not conserved between species, the genomic location of clusters is often retained. We were able to create artificial piRNA clusters in non-native contexts in both mice and flies, indicating that the signals that define these as generative loci must lie within the clusters themselves rather than being implicit in their genomic position. Total RNA and RNA associated with Piwi proteins were isolated and size-fractionated by PAGE into 19-33nt. These were processed and sequenced on the Illumina GA2 platform.
2012-01-01 | E-GEOD-32435 | biostudies-arrayexpress
Project description:Mycelium from the rice blast fungus Magnaporthe oryzae was grown in both rich medium and under nutrient limiting conditions. Genes were identified that were more highly expressed in one condition as compared to the other. Samples were taken from mycelium grown in both complete medium and in glucose minimal medium. Three replicates were taken for each condition.
2012-02-13 | E-GEOD-30256 | biostudies-arrayexpress
Project description:The rice-blast fungus Magnaporthe oryzae is disseminated using a three-celled spore or conidium. Upon landing on the surface of a rice leaf, the conidium germinates and forms a specialised structure for entry into the host plant - the appressorium. In this study we have followed gene expression thoughout germination of the conidium and formation of the appressorium to identify genes that may be important for appressorium function. We have also compared gene expression in the wild-type germinating conidium at four hours to a mutant strain deleted for the MAP kinase pmk1. The pmk1 mutant is unable to form appressoria. Samples were taken from five time-points in wild-type germinating conidia and one time-point in the pmk1 mutant. Two replicates were taken at each time-point.
2012-02-13 | E-GEOD-30069 | biostudies-arrayexpress