Distinguishing reproductive phasiRNAs in grasses from other identically-sized small RNAs using machine learning methods
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ABSTRACT:
ORGANISM(S): Zea mays
PROVIDER: GSE108105 | GEO | 2018/07/23
REPOSITORIES: GEO
Similar Datasets
Project description:Most endogenous siRNAs in Arabidopsis are dependent on RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) for their biogenesis. Recent work has demonstrated that the maize MEDIATOR OF PARAMUTATION1 (mop1) gene is a predicted ortholog of the Arabidopsis RDR2 gene. The mop1 gene is required for establishment of paramutation and maintenance of transcriptional silencing of transposons and transgenes, suggesting the potential involvement of small RNAs. We analyzed small RNAs in wildtype maize and in the isogenic mop1-1 loss-of-function mutant using Illumina’s sequencing-by-synthesis (SBS) technology, which allowed us to characterize the complement of maize small RNAs to considerable depth. Similar to rdr2 in Arabidopsis, in mop1-1, the 24 nt (nucleotide) endogenous heterochromatic short-interfering siRNAs were dramatically reduced resulting in an enrichment of miRNAs and trans-acting siRNAs (ta-siRNAs). In contrast to the Arabidopsis rdr2 mutant, the mop1-1 plants retained a highly abundant heterochromatic ~22 nt class of small RNAs. These data suggest that maize, unlike Arabidopsis, has a second mechanism for heterochromatic siRNA production. The enrichment of miRNAs and loss of 24 nt heterochromatic siRNAs in mop1-1 should be advantageous for miRNA discovery as the maize genome becomes more fully sequenced.
2008-10-01 | GSE12173 | GEO
Project description:Most endogenous siRNAs in Arabidopsis are dependent on RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) for their biogenesis. Recent work has demonstrated that the maize MEDIATOR OF PARAMUTATION1 (mop1) gene is a predicted ortholog of the Arabidopsis RDR2 gene. The mop1 gene is required for establishment of paramutation and maintenance of transcriptional silencing of transposons and transgenes, suggesting the potential involvement of small RNAs. We analyzed small RNAs in wildtype maize and in the isogenic mop1-1 loss-of-function mutant using Illumina’s sequencing-by-synthesis (SBS) technology, which allowed us to characterize the complement of maize small RNAs to considerable depth. Similar to rdr2 in Arabidopsis, in mop1-1, the 24 nt (nucleotide) endogenous heterochromatic short-interfering siRNAs were dramatically reduced resulting in an enrichment of miRNAs and trans-acting siRNAs (ta-siRNAs). In contrast to the Arabidopsis rdr2 mutant, the mop1-1 plants retained a highly abundant heterochromatic ~22 nt class of small RNAs. These data suggest that maize, unlike Arabidopsis, has a second mechanism for heterochromatic siRNA production. The enrichment of miRNAs and loss of 24 nt heterochromatic siRNAs in mop1-1 should be advantageous for miRNA discovery as the maize genome becomes more fully sequenced. This library was derived from maize variety K55 wild-type and mop1 mutant. Immature ears were harvested from plants grown outdoors in Tuscon, AZ. The material was harvested from plants 68 days after germination, with the floral tissue including young tassels 2-3 cm long. Total RNA was isolated using a standard TRIZOL-based method and the small RNA libraries were generated as described by Lu et al. (Methods 2007, 43:110), followed by sequencing with Illumina's SBS method. The adapter sequences were removed, and the abundance of each distinct small RNA was determined. Raw data are unavailable from Illumina
2008-09-30 | E-GEOD-12173 | biostudies-arrayexpress
Project description:Transposable elements (TEs) comprise a substantial portion of many eukaryotic genomes and are typically transcriptionally silenced. RNA–dependent RNA polymerase 2 (RDR2) is a component of the RNA–directed DNA methylation (RdDM) silencing pathway. In maize, loss of mediator of paramutation1 (mop1) encoded RDR2 function results in reactivation of transcriptionally silenced Mu transposons and a substantial reduction in the accumulation of 24 nt short-interfering RNAs (siRNAs) that recruit RNA silencing components. An RNA–seq experiment conducted on shoot apical meristems (SAMs) revealed that, as expected based on a model in which RDR2 generates 24 nt siRNAs that suppress expression, most differentially expressed DNA TEs (78%) were up-regulated in the mop1 mutant. In contrast, most differentially expressed retrotransposons (68%) were down-regulated. This striking difference suggests that distinct silencing mechanisms are applied to different silencing templates. In addition, 6,000 genes (24% of analyzed genes), including nearly 80% (286/361) of genes in chromatin modification pathways, were differentially expressed. Overall, two-thirds of differentially regulated genes were down-regulated in the mop1 mutant. This finding suggests that RDR2 plays a significant role in regulating the expression of not only transposons, but also of genes. A re-analysis of existing small RNA data identified both RDR2–sensitive and RDR2–resistant species of 24 nt siRNAs that we hypothesize may at least partially explain the complex changes in the expression of genes and transposons observed in the mop1 mutant.
2009-11-20 | GSE16789 | GEO
Project description:Transposable elements (TEs) comprise a substantial portion of many eukaryotic genomes and are typically transcriptionally silenced. RNA–dependent RNA polymerase 2 (RDR2) is a component of the RNA–directed DNA methylation (RdDM) silencing pathway. In maize, loss of mediator of paramutation1 (mop1) encoded RDR2 function results in reactivation of transcriptionally silenced Mu transposons and a substantial reduction in the accumulation of 24 nt short-interfering RNAs (siRNAs) that recruit RNA silencing components. An RNA–seq experiment conducted on shoot apical meristems (SAMs) revealed that, as expected based on a model in which RDR2 generates 24 nt siRNAs that suppress expression, most differentially expressed DNA TEs (78%) were up-regulated in the mop1 mutant. In contrast, most differentially expressed retrotransposons (68%) were down-regulated. This striking difference suggests that distinct silencing mechanisms are applied to different silencing templates. In addition, 6,000 genes (24% of analyzed genes), including nearly 80% (286/361) of genes in chromatin modification pathways, were differentially expressed. Overall, two-thirds of differentially regulated genes were down-regulated in the mop1 mutant. This finding suggests that RDR2 plays a significant role in regulating the expression of not only transposons, but also of genes. A re-analysis of existing small RNA data identified both RDR2–sensitive and RDR2–resistant species of 24 nt siRNAs that we hypothesize may at least partially explain the complex changes in the expression of genes and transposons observed in the mop1 mutant. Single sequencing library was constructed for mop1 mutant and non-mutant. Each library was sequenced using 2 lanes on a Solexa flow cell. Processed data file 'ZmB73_4a.53_filtered_genes.fasta' and its README file are linked below as supplementary files. The fasta file contains the gene model ID and corresponding sequence generated from maize genome project. This fasta file was used for the following samples: GSM418173, GSM418174, GSM420173, GSM420174, GSM422828, GSM422829.
2009-11-20 | E-GEOD-16789 | biostudies-arrayexpress
Project description:In plants, the biogenesis of 24 nt and 23 nt small interfering RNAs (siRNAs) requires NUCLEAR RNA POLYMERASE IV (Pol IV), RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) and DICER-LIKE 3 (DCL3). We show that single-stranded M13 bacteriophage DNA can be used as a template for siRNA synthesis in vitro. Deep sequencing of RNAs produced from the in vitro reactions of Pol IV, RDR2 and DCL3 shows that Pol IV transcribes the DNA into first-strand RNAs which RDR2 then uses as templates to synthesize complementary second strands. These siRNA precursor transcripts made by Pol IV and RDR2 are mostly 30-50 nt. An untemplated 3' terminal nucleotide is a characteristic of RDR2 transcripts. DCL3 dicing of double-stranded precursor RNAs synthesized by Pol IV and RDR2 generates siRNAs that are mostly 24 nt, with a smaller population of 23 nt also produced.
2019-07-01 | GSE126086 | GEO
Project description:Small interfering RNAs (siRNAs) are critical for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21-, 22-, or 24- nucleotides (nt), wherein the 21- and 24-nt siRNAs mediate mRNA cleavage and DNA methylation2,3, respectively. However, the biological functions of 22-nt siRNAs remain elusive. Here we report the identification and characterization of a group of endogenous 22-nt siRNAs generated from the action of DICER-LIKE 2 (DCL2). When cytoplasmic RNA decay and DCL4 are deficient, the massive accumulation of 22-nt siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defect, and pigmentation. Notably, two genes that encode nitrate reductases, NIA1 and NIA2, produce nearly half of the total of 22-nt siRNAs. Production of 22-nt siRNA triggers explosive self-amplification that leads to a small RNA storm, and induces dramatic translational repression both gene-specifically and globally. 22-nt siRNAs are also found to preferentially accumulate upon nitrogen deficiency, which acts to restrain plant growth and promote stress responses. Thus, our research uncovers the unique properties of 22-nt siRNAs, a previously unexplored class of plant siRNAs, and highlights the length of small RNA as a major functional determinant.
2020-04-13 | GSE148513 | GEO
Project description:Small interfering RNAs (siRNAs) are critical for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21-, 22-, or 24- nucleotides (nt), wherein the 21- and 24-nt siRNAs mediate mRNA cleavage and DNA methylation2,3, respectively. However, the biological functions of 22-nt siRNAs remain elusive. Here we report the identification and characterization of a group of endogenous 22-nt siRNAs generated from the action of DICER-LIKE 2 (DCL2). When cytoplasmic RNA decay and DCL4 are deficient, the massive accumulation of 22-nt siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defect, and pigmentation. Notably, two genes that encode nitrate reductases, NIA1 and NIA2, produce nearly half of the total of 22-nt siRNAs. Production of 22-nt siRNA triggers explosive self-amplification that leads to a small RNA storm, and induces dramatic translational repression both gene-specifically and globally. 22-nt siRNAs are also found to preferentially accumulate upon nitrogen deficiency, which acts to restrain plant growth and promote stress responses. Thus, our research uncovers the unique properties of 22-nt siRNAs, a previously unexplored class of plant siRNAs, and highlights the length of small RNA as a major functional determinant.
2020-04-13 | GSE148512 | GEO
Project description:Small interfering RNAs (siRNAs) are critical for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21-, 22-, or 24- nucleotides (nt), wherein the 21- and 24-nt siRNAs mediate mRNA cleavage and DNA methylation2,3, respectively. However, the biological functions of 22-nt siRNAs remain elusive. Here we report the identification and characterization of a group of endogenous 22-nt siRNAs generated from the action of DICER-LIKE 2 (DCL2). When cytoplasmic RNA decay and DCL4 are deficient, the massive accumulation of 22-nt siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defect, and pigmentation. Notably, two genes that encode nitrate reductases, NIA1 and NIA2, produce nearly half of the total of 22-nt siRNAs. Production of 22-nt siRNA triggers explosive self-amplification that leads to a small RNA storm, and induces dramatic translational repression both gene-specifically and globally. 22-nt siRNAs are also found to preferentially accumulate upon nitrogen deficiency, which acts to restrain plant growth and promote stress responses. Thus, our research uncovers the unique properties of 22-nt siRNAs, a previously unexplored class of plant siRNAs, and highlights the length of small RNA as a major functional determinant.
2020-02-14 | GSE135962 | GEO
Project description:Small interfering RNAs (siRNAs) are critical for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21-, 22-, or 24- nucleotides (nt), wherein the 21- and 24-nt siRNAs mediate mRNA cleavage and DNA methylation2,3, respectively. However, the biological functions of 22-nt siRNAs remain elusive. Here we report the identification and characterization of a group of endogenous 22-nt siRNAs generated from the action of DICER-LIKE 2 (DCL2). When cytoplasmic RNA decay and DCL4 are deficient, the massive accumulation of 22-nt siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defect, and pigmentation. Notably, two genes that encode nitrate reductases, NIA1 and NIA2, produce nearly half of the total of 22-nt siRNAs. Production of 22-nt siRNA triggers explosive self-amplification that leads to a small RNA storm, and induces dramatic translational repression both gene-specifically and globally. 22-nt siRNAs are also found to preferentially accumulate upon nitrogen deficiency, which acts to restrain plant growth and promote stress responses. Thus, our research uncovers the unique properties of 22-nt siRNAs, a previously unexplored class of plant siRNAs, and highlights the length of small RNA as a major functional determinant.
2020-02-14 | GSE135961 | GEO
Project description:Small interfering RNAs (siRNAs) are critical for proper development and immunity in eukaryotes1. Plants produce siRNAs with lengths of 21-, 22-, or 24- nucleotides (nt), wherein the 21- and 24-nt siRNAs mediate mRNA cleavage and DNA methylation2,3, respectively. However, the biological functions of 22-nt siRNAs remain elusive. Here we report the identification and characterization of a group of endogenous 22-nt siRNAs generated from the action of DICER-LIKE 2 (DCL2). When cytoplasmic RNA decay and DCL4 are deficient, the massive accumulation of 22-nt siRNAs causes pleiotropic growth disorders, including severe dwarfism, meristem defect, and pigmentation. Notably, two genes that encode nitrate reductases, NIA1 and NIA2, produce nearly half of the total of 22-nt siRNAs. Production of 22-nt siRNA triggers explosive self-amplification that leads to a small RNA storm, and induces dramatic translational repression both gene-specifically and globally. 22-nt siRNAs are also found to preferentially accumulate upon nitrogen deficiency, which acts to restrain plant growth and promote stress responses. Thus, our research uncovers the unique properties of 22-nt siRNAs, a previously unexplored class of plant siRNAs, and highlights the length of small RNA as a major functional determinant.
2020-02-14 | GSE135959 | GEO