Micro (mi)RNAs are small non-coding RNAs with key regulatory functions. Recent advances in the field allowed researchers to identify their targets. However, much less is known regarding the regulation of miRNA themselves. The accumulation of these tiny regulators can be modulated at various levels during their biogenesis from the transcription of the primary transcript (pri-miRNA) to the stability of the mature miRNA. Here, we studied the importance of the pri-miRNA secondary structure for the regulation of mature miRNAs accumulation. To this end, we used the Kaposi’s sarcoma herpesvirus, which encodes a cluster of twelve pre-miRNAs. Using small RNA profiling and quantitative northern blot analysis, we measured the absolute amount of each mature miRNAs in different cellular context. We found that the difference in expression between the least and most expressed viral miRNA could be as high as 60-fold. Using high-throughput selective 2’-hydroxyl acylation analyzed by primer extension (hSHAPE), we then determined the secondary structure of the long primary transcript. We found that highly expressed miRNAs derived from optimally structured regions within the pri-miRNA. Finally, we confirmed the importance of the local structure by swapping stem-loops for highly and lowly expressed miRNAs, which resulted in a perturbed accumulation of the mature miRNA. Overall design: Examination of sRNA profiles in 3 independent B cell lines expressing KSHV miRNAs or infected with KSHV, without replicate
Importance of the RNA secondary structure for the relative accumulation of clustered viral microRNAs.
No sample metadata fields
View SamplesHerpesviruses are known to encode micro (mi)RNAs and to use them to regulate the expression of both viral and cellular genes. The genome of Kaposis sarcoma herpesvirus (KSHV) encodes a cluster of twelve miRNAs, which are abundantly expressed during both latency and lytic infection. Relatively few cellular targets of KSHV miRNAs are known. Here, we used a microarray expression profiling approach to analyze the transcriptome of both B lymphocytes and endothelial cells stably expressing KSHV miRNAs and monitor the changes induced by the presence of these miRNAs. We generated a list of potential cellular targets by looking for miRNA seed-match-containing transcripts that were significantly down regulated upon KSHV miRNAs expression. Interestingly, the overlap of putative targets identified in B lymphocytes and endothelial cells was minimal, suggesting a tissue-specific target-regulation by viral miRNAs. Among the putative targets, we identified caspase 3, a critical factor for the control of apoptosis, which we validated using luciferase reporter assays and western blotting. In functional assays we obtained further evidence that KSHV miRNAs indeed protect cells from apoptosis.
Kaposi's sarcoma herpesvirus microRNAs target caspase 3 and regulate apoptosis.
Cell line
View SamplesAuxin is a key phytohormone regulating central processes in plants that include embryo development, lateral root growth and flower maturation among others. Auxin is sensed by a set of F-Box proteins of the TIR1/AFB3 family triggering auxin dependent responses by a pathway that involves an interplay between the Aux/IAA transcription repressors and the ARF transcription factors. We have previously shown that the AFB3 auxin receptor has a specific role in coordinating primary and lateral root growth to external and internal nitrate availability (Vidal et al., 2010). In this work, we used an integrated genomics, bioinformatics and molecular genetics approach to dissect regulatory networks acting downstream AFB3 that are activated by a transient nitrate treatment in Arabidopsis roots. Our systems approach unraveled key components of the AFB3 regulatory network leading to changes in lateral root growth in response to nitrate.
Systems approaches map regulatory networks downstream of the auxin receptor AFB3 in the nitrate response of Arabidopsis thaliana roots.
Specimen part, Treatment
View SamplesDuring each life cycle germ cells preserve and pass on both genetic and epigenetic information. In C. elegans, the ALG-3/4 Argonaute (AGO) proteins and their small-RNA cofactors are expressed during male gametogenesis and promote male fertility. Here we show that the CSR-1 AGO functions with ALG-3/4 to positively regulate target genes required for spermiogenesis. Our findings suggest that ALG-3/4 functions during spermatogenesis to amplify a small-RNA signal that represents an epigenetic memory of male-specific gene expression, while CSR-1, which is abundant in mature sperm, transmits this memory to offspring. Surprisingly, in addition to small RNAs targeting male-specific genes, we show that males also harbor an extensive repertoire of CSR-1 small RNAs targeting oogenesis-specific mRNAs. Together these findings suggest that C. elegans sperm transmit not only the genome but also epigenetic binary signals in the form of Argonaute/small-RNA complexes that constitute a memory of which genes were active in preceding generations. Overall design: Examine small RNA changes in WT and alg-3/4 mutant males cultured at 20°C and 25°C, as well as determine the small RNAs enriched in a FLAG::CSR-1 IP from male worms grown at 25°C. mRNA sequencing was also performed to determine how transcripts targeted by small RNAs change in mutant background at 20°C and 25°C.
Argonautes promote male fertility and provide a paternal memory of germline gene expression in C. elegans.
Subject
View SamplesFemale infertility syndromes are among the most prevalent chronic health disorders in women, but their molecular basis remains unknown because of the complexity of oogenesis and uncertainty regarding the number and identity of ovarian factors controlling the assembly, preservation, and maturation of ovarian follicles. To systematically discover such ovarian fertility factors en masse, we employed a mouse model (Foxo3), where follicles are assembled normally but are then synchronously activated. Gene expression profiling of mutant and normal ovaries led to the identification a surprisingly large set of ovarian factors. The set included the vast majority of known ovarian factors, many of which when mutated produce female sterility phenotypes, but most were novel. Subsequent analyses revealed novel classes of ovarian factors and significant overrpresentation on the X chromosome, among other insights into the general properties of oogenesis genes and their patterns of expression.
Genomewide discovery and classification of candidate ovarian fertility genes in the mouse.
No sample metadata fields
View SamplesInsulin like growth factor 1 (IGF-1) has a central role in mammalian hearing and hearing loss. The auditory and vestibular systems form the inner ear and have a common developmental origin. During chicken early development IGF-1 modulates neurogenesis of the cochleovestibular ganglion but no further studies have been conducted to explore the potential role of IGF-1 in the vestibular system.
Comparative gene expression study of the vestibular organ of the Igf1 deficient mouse using whole-transcript arrays.
Specimen part
View SamplesThe high-mobility-group (HMG) proteins are the most abundant non-histone chromatin-associated proteins. Here we deciphered the role of the high mobility group AT-hook protein 2 (HMGA2) during lung development by analyzing the lung of Hmga2 deficient mice (Hmga2-/-).We found that Hmga2 is expressed in the mouse embryonic lung at the distal airways. Analysis of Hmga2-/- mice showed that Hmga2 is required for proper cell proliferation and distal epithelium differentiation during embryonic lung development. Hmga2 knockout (KO) led to enhanced canonical WNT signaling due to an increased expression of secreted WNT glycoproteins Wnt2b, Wnt7b and Wnt11 as well as a reduction of the WNT signaling antagonizing proteins GATA6 (GATA binding protein 6) and FZD2 (frizzled homolog 2).
Hmga2 is required for canonical WNT signaling during lung development.
Specimen part
View SamplesSETD5 gene mutations have been identified as a frequent cause of idiopathic intellectual disability. Here we show that Setd5 haploinsufficient mice present developmental defects such as abnormal brain to body weight ratio and neural crest defect associated phenotypes. Furthermore, Setd5 mutant mice show impairments in cognitive tasks, enhanced long-term potentiation, delayed ontogenetic profile of ultrasonic vocalisation and behavioural inflexibility. Behavioural issues are accompanied by abnormal expression of postsynaptic density proteins previously associated with cognition. Our data suggest that Setd5 might regulate RNA polymerase II dynamics and gene transcription during development and learning via its interaction with the Hdac3 and Paf1 complexes. Our results emphasize the decisive role of Setd5 in a biological pathway found to be disrupted in intellectual disability and autism spectrum disorder patients. Overall design: RNA-sequencing for wild type and Setd5 heterozygous knockout mice in two settings. First, in whole embryo samples (age E9.5), three biological replicates each. Second, gene expression changes due to contextual fear conditioning (CFC) was studied by comparing baseline transcription in homecage (HC) mice with transcription one hour (CFC_1h) or three hours (CFC_3h) after fear conditioning (4-5 biological replicates per time point and genotype).
Haploinsufficiency of the intellectual disability gene SETD5 disturbs developmental gene expression and cognition.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Comprehensive genomic analysis identifies novel subtypes and targets of triple-negative breast cancer.
Sex, Age, Specimen part, Disease stage, Race
View SamplesRecent meta-analyses suggest triple-negative breast cancer (TNBC) is a heterogenous disease. In this study we sought to define these TNBC subtypes and identify subtype-specific markers and targets.
Comprehensive genomic analysis identifies novel subtypes and targets of triple-negative breast cancer.
Sex, Age, Specimen part, Disease stage, Race
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