Longitudinal bone growth depends upon the execution of an intricate series of cellular activities by epiphyseal growth plate chondrocytes. In order to better understand these coordinated events, microarray analysis was used to compare gene expression in chondrocytes isolated from the proliferative and hypertrophic zones of the avian growth plate.
Use of microarray analysis to study gene expression in the avian epiphyseal growth plate.
Age, Specimen part
View SamplesUnderstanding the physiological relevance of structures in mammalian mRNAs remains elusive, especially considering the global unfolding of mRNA structures in eukaryotic organisms recently examined, as well as the decade-long observation that mRNAs generally seem no more likely than random sequences to be stably folded. Here we show that RNA secondary structures, mostly weak and close-to-random, facilitate the 3'-end processing of thousands of human mRNAs by juxtaposing poly(A) signals (PASs) and cleavage sites that are otherwise too far apart. Folding of these 3'-end structures also enhances mRNA stability. Global structure probing shows that 3'-end regions are indeed folded in cells despite substantial unfolding of PAS-upstream regions. Analyses of thousands of ectopically expressed variants prove that folding both enhances processing and increases stability. Mutagenesis of a genomic locus further implicates structure-controlled processing in regulating neighboring gene expression. These results reveal widespread roles for RNA structure in mammalian mRNA biogenesis and metabolism. Overall design: This series includes 8 samples designed to measure the efficiency of 3'' end processing from a reporter library expressed in HEK293T cells and HeLa cells, in steady state or in nascent RNAs (by 4sU labeling and capture).
Widespread Influence of 3'-End Structures on Mammalian mRNA Processing and Stability.
Cell line, Subject
View SamplesSmall endogenous C. elegans RNAs from L4 and young adult worms were prepared for sequencing using a protocol derived from Batista et al., (2008) and Lau et al. (2001). The small-RNA libraries were constructed using a method that does not require a 5' monophosphate (called 5' monophosphate-independent method, Ambros et al., 2003) to profile secondary siRNAs that have 5' triphosphorylated G. All preprocessed small-RNA reads were mapped to genome (ce6), allowing no mismatches. After excluding miRNAs, 21U RNAs, rRNAs, and other structural ncRNAs, the remaining reads were classified as 22G RNAs, 26G RNAs, and other siRNAs, based on their length and 5' terminal nucleotide. Overall design: Small-RNA libraries were sequenced in L4 and young adult stages in C.elegans.
Long noncoding RNAs in C. elegans.
Cell line, Subject
View SamplesControl of metazoan embryogenesis shifts from maternal to zygotic gene products as the zygotic genome becomes transcriptionally activated. In Drosophila, zygotic genome activation (ZGA) begins with a minor wave, but technical challenges have hampered the identification of early transcripts or obscured the onset of their transcription. Here, we develop an approach to isolate transcribed mRNAs and apply it over the course of the minor wave and the start of the major wave of Drosophila ZGA. Our results increase known genes of the minor wave by 10 fold and show that this wave is continuous and gradual. Transposable-element mRNAs are also produced, but discontinuously. Genes in the early and middle part of the minor wave are short with few if any introns, and their transcripts are frequently aborted and tend to have retained introns, suggesting that inefficient splicing as well as rapid cell divisions constrain the lengths of early transcripts. Overall design: The goal of this study is to use NGS to identify zygotic transcripts produced during early zygotic genome activation in Drosophila.
Early genome activation in <i>Drosophila</i> is extensive with an initial tendency for aborted transcripts and retained introns.
Subject
View SamplesWe obtained global measurements of decay and translation rates for mammalian mRNAs with alternative 3'' untranslated regions (3'' UTRs). Overall design: 1 3P-Seq sample from 3T3 cells and 1 3P-Seq sample from mouse ES cells; 2 2P-Seq steady state and 4 2P-Seq with actinomycin D; 6 polysome fraction 2P-Seq
3' UTR-isoform choice has limited influence on the stability and translational efficiency of most mRNAs in mouse fibroblasts.
Specimen part, Treatment, Subject
View SamplesThe miR-16 family, which targets genes important for the G1-S transition, is a known modulator of the cell cycle, and members of this family are often deleted or down-regulated in many types of cancers. Here we report the reciprocal relationship - that of the cell cycle controlling the miR-16 family. Levels of this family increase rapidly as cells are arrested in G0. Conversely, as cells are released from G0 arrest, levels of the miR-16 family rapidly decrease. Such rapid changes are made possible by the unusual instabilities of several family members. The repression mediated by the miR-16 family is sensitive to these cell cycle changes, which suggests that the rapid up-regulation of the miR-16 family reinforces cell cycle arrest in G0. Upon cell cycle re-entry, the rapid decay of several members allows levels of the family to decrease, alleviating repression of target genes and allowing proper resumption of the cell cycle. Overall design: Small RNAs were profiled by high-throughput sequencing either during synchronous release after serum starvation or during cell-cycle arrest by contact inhibition.
MicroRNA destabilization enables dynamic regulation of the miR-16 family in response to cell-cycle changes.
Specimen part, Cell line, Subject
View SamplesThe RNA interference (RNAi) pathway is found in most eukaryotic lineages but curiously is absent in others, including that of Saccharomyces cerevisiae. Here, we show that reconstituting RNAi in S. cerevisiae causes loss of a beneficial dsRNA virus, known as killer virus. Incompatibility between RNAi and killer viruses extends to other fungal species, in that RNAi is absent in all species known to possess dsRNA killer viruses, whereas killer viruses are absent in closely related species that retained RNAi. Thus, the advantage imparted by acquiring and retaining killer viruses explains the persistence of RNAi-deficient species during fungal evolution. Overall design: Examine mRNA abundance of S. cerevisiae wild-type (DPB249), +AGO1 (DPB252), +DCR1 (DPB255) and +AGO1, DCR1 (DPB258).
Compatibility with killer explains the rise of RNAi-deficient fungi.
Cell line, Subject
View SamplesThe RNA interference (RNAi) pathway is found in most eukaryotic lineages but curiously is absent in others, including that of Saccharomyces cerevisiae. Here, we show that reconstituting RNAi in S. cerevisiae causes loss of a beneficial dsRNA virus, known as killer virus. Incompatibility between RNAi and killer viruses extends to other fungal species, in that RNAi is absent in all species known to possess dsRNA killer viruses, whereas killer viruses are absent in closely related species that retained RNAi. Thus, the advantage imparted by acquiring and retaining killer viruses explains the persistence of RNAi-deficient species during fungal evolution. Overall design: Employ high-throughput sequencing of endogenous small RNAs from Saccharomyces cerevisiae wild-type and RNAi-reconstituted strains.
Compatibility with killer explains the rise of RNAi-deficient fungi.
Cell line, Subject
View SamplesNoncoding RNAs (ncRNAs) play increasingly appreciated gene-regulatory roles. Here, we describe a regulatory network centered on four ncRNAs—a long ncRNA, a circular RNA, and two microRNAs—using gene editing in mice to probe the molecular consequences of disrupting key components of this network. The long ncRNA Cyrano uses an extensively paired site to miR-7 to trigger destruction of this microRNA. Cyrano-directed miR-7 degradation is much more efficient than previously described examples of target-directed microRNA degradation, which come primarily from studies of artificial and viral RNAs. By reducing miR-7 levels, Cyrano prevents repression of miR-7–targeted mRNAs and enables the accumulation of Cdr1as, a circular RNA known to regulate neuronal activity. Without Cyrano, excess miR-7 causes cytoplasmic destruction of Cdr1as, in part through enhanced slicing of Cdr1as by a second miRNA, miR-671. Thus, several types of ncRNAs can collaborate to establish a sophisticated regulatory network. Overall design: mRNA expression profiling by RNA-seq of 10 tissues from wild-type (WT) and Cyrano–/– (CyrKO) mice. This study consists of 96 polyA-selected unstranded Tru-seq libraries prepared from 4–6 biological replicates per genotype for each tissue.
A Network of Noncoding Regulatory RNAs Acts in the Mammalian Brain.
Sex, Age, Specimen part, Cell line, Subject
View SamplesNoncoding RNAs (ncRNAs) play increasingly appreciated gene-regulatory roles. Here, we describe a regulatory network centered on four ncRNAs—a long ncRNA, a circular RNA, and two microRNAs—using gene editing in mice to probe the molecular consequences of disrupting key components of this network. The long ncRNA Cyrano uses an extensively paired site to miR-7 to trigger destruction of this microRNA. Cyrano-directed miR-7 degradation is much more efficient than previously described examples of target-directed microRNA degradation, which come from studies of artificial and viral RNAs. By reducing miR-7 levels, Cyrano prevents repression of miR-7–targeted mRNAs and enables the accumulation of Cdr1as, a circular RNA known to regulate neuronal activity. Without Cyrano, excess miR-7 causes cytoplasmic destruction of Cdr1as, in part through enhanced slicing of Cdr1as by a second miRNA, miR-671. Thus, several types of ncRNAs can collaborate to establish a sophisticated regulatory network. Overall design: mRNA expression profiling by RNA-seq of cerebellum and cortex from wild-type (WT), Cyrano miR-7 site mutant (CyrMut), Cyrano–/– (CyrKO), and Mir7a1–/–; Mir7b–/– (Mir7DKO) mice. This study consists of 33 polyA-selected stranded NEXTflex libraries prepared from 3-4 biological replicates for each tissue and each genotype. To minimize batch effects, libraries for wild-type tissues were prepared and sequenced for each experiment and only intra-experiment comparisons were made.
A Network of Noncoding Regulatory RNAs Acts in the Mammalian Brain.
Sex, Age, Specimen part, Cell line, Subject
View Samples