Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3 -5 mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5 -3 exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). A number of endogenous genes, including many miRNA target genes, manifest transitive 21-22 nt siRNA production and compromised gene expression in ein5 ski2 in an RDR6-dependent manner. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5 -3 and 3 -5 cytoplasmic mRNA decay pathways. In this experiment, we did three replicates in sequencing that help increase the power in identify the differentially represented genes.The sequencing depth was also increased. Therefore we identified more siRNA-generating loci than that in previous study (GSE52408) (441 vs. 200 loci). Examination of small RNA profiles in 4 genotypes with 3 biological replicates each.
Project description:A loss-of-function mutant in the SKI2 helicase in Arabidopsis was shown to accumulate 5'-cleavage fragments of several miRNA targets. Small RNAs in ski2 single and ski2/rdr6 double mutants (two biological replicates of each genotype) were next analysed by NGS. The data show that several miRNA targets produce RDR6-dependent siRNAs upon inactivation of SKI2. Files containing these NGS data are deposited here. Seeds were surface sterilized and germinated on MS medium for 2 weeks. The seedlings were grown on soil until flowering stage in a 16h light period. The inflorescences were harvested and used to prepare RNA. Small RNA libraries were prepared using the NEBnext Multiplex small RNA library prep kit for Illumina sequencing.
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3 -5 mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5 -3 exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). A number of endogenous genes, including many miRNA target genes, manifest transitive 21-22 nt siRNA production and compromised gene expression in ein5 ski2 in an RDR6-dependent manner. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5 -3 and 3 -5 cytoplasmic mRNA decay pathways. In this experiment, we did three replicates in sequencing that help increase the power in identify the differentially represented genes.The sequencing depth was also increased. Therefore we identified more siRNA-generating loci than that in previous study (GSE52408) (441 vs. 200 loci).
2015-04-13 | GSE57936 | GEO
Project description:Analysis of the RDR6-dependent ein5 ski2 profile in Arabidopsis
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3’-5’ mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5’-3’ exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). A number of endogenous genes, including many miRNA target genes, manifest transitive 21-22 nt siRNA production and compromised gene expression in ein5 ski2 in an RDR6-dependent manner. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5’-3’ and 3’-5’ cytoplasmic mRNA decay pathways.
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3’-5’ mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5’-3’ exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). Compared with Col-0, 4394 genes exhibited differential expression in ein5-1 ski2-3, much more than those in the ein5-1 (1138 genes) or ski2-3 (1040 genes) single mutant (2-fold cutoff, p < 0.01, FDR < 0.05), suggesting a largely disturbed transcriptome in the absence of both EIN5 and SKI2. While a small overlap was found between the differentially expressed genes in e/C and s/C comparisons, the gene lists from es/C, es/e and es/s comparisons (2-fold cutoff, p < 0.01, FDR < 0.05) largely overlapped with each other, indicating a collaborative function of EIN5 and SKI2 on a transcriptome-wide scale. The 1670 genes overlapped in the es/C, es/e and es/s comparisons included 1306 upregulated genes and 360 downregulated genes with only 4 genes as exception. 994 of the 1306 upregulated genes (76.1%) and 273 of the 360 downregulated genes (75.8%) were differentially expressed in the es/res comparison like that in es/C, es/e and es/s, indicating a substantial supression of the redundant function of EIN5 and SKI2 by RDR6. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5’-3’ and 3’-5’ cytoplasmic mRNA decay pathways. Examination of transcriptomes in 6 genotypes.
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3’-5’ mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5’-3’ exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). Compared with Col-0, 4394 genes exhibited differential expression in ein5-1 ski2-3, much more than those in the ein5-1 (1138 genes) or ski2-3 (1040 genes) single mutant (2-fold cutoff, p < 0.01, FDR < 0.05), suggesting a largely disturbed transcriptome in the absence of both EIN5 and SKI2. While a small overlap was found between the differentially expressed genes in e/C and s/C comparisons, the gene lists from es/C, es/e and es/s comparisons (2-fold cutoff, p < 0.01, FDR < 0.05) largely overlapped with each other, indicating a collaborative function of EIN5 and SKI2 on a transcriptome-wide scale. The 1670 genes overlapped in the es/C, es/e and es/s comparisons included 1306 upregulated genes and 360 downregulated genes with only 4 genes as exception. 994 of the 1306 upregulated genes (76.1%) and 273 of the 360 downregulated genes (75.8%) were differentially expressed in the es/res comparison like that in es/C, es/e and es/s, indicating a substantial supression of the redundant function of EIN5 and SKI2 by RDR6. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5’-3’ and 3’-5’ cytoplasmic mRNA decay pathways.
Project description:The Arabidopsis genome contains a highly complex and abundant population of small RNAs, and many of the endogenous siRNAs are dependent on RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) for their biogenesis. By analyzing an rdr2 loss-of-function mutant using two different parallel sequencing technologies, MPSS and 454, we characterized the complement of miRNAs expressed in Arabidopsis inflorescence to considerable depth. Nearly all known miRNAs were enriched in this mutant and we identified 13 new miRNAs, all of which were relatively low abundance and constitute new families. Trans-acting siRNAs (ta-siRNAs) were even more highly enriched. Computational and gel blot analyses suggested that the minimal number of miRNAs in Arabidopsis is approximately 155. The size profile of small RNAs in rdr2 reflected enrichment of 21-nt miRNAs and other classes of siRNAs like ta-siRNAs, and a significant reduction in 24-nt heterochromatic siRNAs. Other classes of small RNAs were found to be RDR2-independent, particularly those derived from long inverted repeats and a subset of tandem repeats. The small RNA populations in other Arabidopsis small RNA biogenesis mutants were also examined; a dcl2/3/4 triple mutant showed a similar pattern to rdr2, whereas dcl1-7 and rdr6 showed reductions in miRNAs and ta-siRNAs consistent with their activities in the biogenesis of these types of small RNAs. Deep sequencing of mutants provides a genetic approach for the dissection and characterization of diverse small RNA populations and the identification of low abundance miRNAs. Keywords: small RNA sequences generated by 454 sequencing