In this project, we used RNA-seq to measure mRNA expression in four natural isolates of C.elegans at the L4 larval stage. In addition, we used RNA-seq to measure mRNA expression in young adult animals in two isolates, n2 and CB4856. These expression measurements were used as part of a study to assess the natural variation in loss of function phenotypes in C.elegans. This was published as Vu et al. (2015) Natural Variation in Gene Expression Modulates the Severity of Mutant Phenotypes
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Sex, Specimen part, Treatment
View SamplesNo description.
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Cell line
View SamplesRNA-Seq of reciprocally crossed Black6 x CAST hybrid mouse tissues.
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Sex, Cell line
View SamplesWhile the genome sequence of many animals is now complete, their transcriptomes are less well characterised. Both genome-scale tiling arrays and massively parallel sequencing now allow transcriptomes to be mapped at unprecedented depth. We used both technologies to map the C. elegans transcriptome across development. This unbiased overview can serve as a framework for assessing transcriptome changes in a mutant animal and we compared the wild-type data with that of animals that have lost the nonsense-mediated decay (NMD) pathway. Results We find that while the great majority of detectable transcripts map to known gene structures, over 5% of transcribed regions are novel, falling outside current gene annotations. We show that at least 40% of these are novel exons. We also used both technologies to assess isoform complexity and estimate that at least 17% of genes change their major isoform across development. Having mapped the wild-type transcriptome, we examined how this is perturbed in animals lacking nonsense -mediated decay (NMD). NMD prevents expression of prematurely truncated proteins by degrading transcripts containing premature termination codons (PTCs). We find that ~20% of all genes produce transcripts that appear to be targets for NMD. While most of these arise from splicing errors, NMD targets are also enriched for transcripts that contain short open reading frames upstream of the predicted translational start (uORFs). We find an intriguing relationship between the strength of Kozak consensus surrounding the true start codon and the degree to which these uORF containing transcripts are targeted by NMD, suggesting that translational efficiency may be coupled to transcript turnover via the NMD pathway for many transcripts. Conclusions We have generated a high-resolution map of the C. elegans transcriptome and have used it to identify transcripts that are endogenous targets of the NMD machinery. We find that these targets arise principally through splicing errors and suggest that splicing and NMD are highly interlinked processes.
High resolution transcriptome maps for wild-type and nonsense-mediated decay-defective Caenorhabditis elegans.
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View SamplesMaize exhibits levels of structural variation (SV) of non-repeat sequences that are unprecedented among higher eukaryotes. This SV includes hundreds of copy number variants (CNVs) and thousands of presence/absence variants (PAVs). Many of the PAVs contain intact, expressed, single-copy genes that are present in one haplotype but absent from another. The goal of this project is to test the hypothesis that differences in gene copy number (both gains and losses) contribute to the extraordinary phenotypic diversity and plasticity of maize. Maize is a good model for these studies because it exhibits a rapid decay of linkage disequilibrium (LD) and because a draft genome sequence of the B73 inbred and mapping populations are available. As a first step, the "Zeanome", a near-complete set of genes present in B73, other maize lines and the wild ancestor of maize (teosinte), is being defined using transcriptomic data.
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View SamplesRNA-seq transcriptome profiles of genetically fate-mapped serotonin neurons, manually sorted from multiple anatomic domains, at both population and single cell resolution.
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Sex, Specimen part, Cell line
View SamplesHeterosis which is the improved vigor of F1-hybrids compared to their parents is widely exploited in maize (Zea mays L.) breeding to produce elite hybrids of superior yield. The transcriptomes of the maize inbred lines B73 and Mo17 and their reciprocal hybrid offspring were surveyed in the meristematic zone, the elongation zone, cortex and stele tissues of primary roots, prior to the developmental manifestation of heterosis. Single parent expression (SPE) is consistent with the dominance model for heterosis in that it denotes genes that are expressed in only one parent but in both reciprocal hybrids. In primary root tissues, between 1,027 (elongation zone) and 1,206 (stele) SPE patterns were observed. As a consequence, hybrids displayed in each tissue >400 active genes more than either parent. Analysis of tissue-specific SPE dynamics revealed that 1,233 of 2,233 SPE genes displayed SPE in all tissues in which they were expressed while 1,000 SPE genes displayed in at least one tissue a non-SPE pattern. In addition, 64% (17,351/ 27,164) of all expressed genes were assigned to the two subgenomes which are the result of an ancient genome duplication. By contrast, only between 18 and 25% of the SPE genes were assigned to a subgenome suggesting that a disproportionate number of SPE genes are evolutionary young and emerged after genome duplication. We hypothesize that this phenomenon is associated with human selection of favorable maize genotypes which might primarily affect younger genes rather than genes whose functions have been conserved for millions of years.
Nonsyntenic genes drive highly dynamic complementation of gene expression in maize hybrids.
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View SamplesThe genomic distribution of trait-associated SNPs (TASs) discovered in genome-wide association studies (GWAS) can provide insight into the genetic architecture of complex traits and the design of future studies. Here we report on a maize GWAS that identified TASs underlying five quantitative traits measured across a large panel of samples and examine the characteristics of these TASs. A set of SNPs obtained via RNA sequencing (RNA-seq), most of which are located within annotated genes (~87%) were complemented with additional SNPs from the maize HapMap Project that contains approximately equal proportions of intragenic and intergenic SNPs. TASs were identified via a genome scan while controlling for polygenic background effects. The diverse functions of TAS-containing candidate genes indicate that complex genetic networks shape these traits. The vast majority of the TAS-containing candidate genes have dynamic expression levels among developmental stages. Overall, TASs explain 44~54% of the total phenotypic variation for these traits, with equal contributions from intra- and inter-genic TASs. Association of ligueless2 with upper leaf angle was implicated by two intragenic TASs; rough sheath1 was associated with leaf width by an upstream intergenic TAS; and Zea agamous5 was associated with days to silking by both intra- and inter-genic TASs. A large proportion (82%) of these TASs comes from noncoding regions, similar to findings from human diseases and traits. However, TASs were enriched in both intergenic (53%) and promoter 5kb (24%) regions, but under-represented in a set of nonsynonymous SNPs.
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View SamplesStudy on sex biased gene expression during multiple life stages and different strains in malaria vector Anopheles gambiae
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Sex, Specimen part, Cell line, Treatment
View SamplesCirculating cell-free RNA in the blood provides a potential window into the health, phenotype, and developmental programs of a variety of human organs. We used high-throughput methods of RNA analysis such as microarrays and next-generation sequencing to characterize the global landscape of circulating RNA in human subjects. By focusing on tissue-specific genes, we were able to identify the relative contributions of these tissues to circulating RNA and monitor changes during tissue development and neurodegenerative disease states.
Noninvasive in vivo monitoring of tissue-specific global gene expression in humans.
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