ABSTRACT: 3'UTR sequencing was performed in indicated C.elegans strains to obtain information about alterations in 3'UTR lengths and alternative polyadenylation events.
Project description:Temperature, as a universal enviromental factor, has prolonged effect on physiological and pathological functions of different species. In order to expolore the temperol effect of temperature on C.elegans longevity, we used microarray to check the whole-genome expression profiling of L4 larvae and Day3-old adults of C.elegans maintaining at different temperature Adult worms are collected after maintained at 25 degree and 15 degree for 3days from later L4 stage, while Larva worms are collected after growing at 25 degree and 15 degree from embryo to late L4 stege. Then total RNA are extracted with TRI reagent(Life Technologies) from~120 adults or ~300 larvae. The concentrations and quality of total RNA are checked with Thermo Nanodrop 2000c(Thermo Scientific,WilminGton,DE) and Agilent 2100 BioAnalyzer (Agilent Technologies, Palo Alto, CA). Total RNA samples were hybrydized with Affymetrix C. elegans Gene 1.1 ST Array Strip. Preparation of cDNA, hybridization, quality controls and scanning of arrays were performed according to the manufacturer's protocol (Affymetrix, Santa Clara, CA) at the microarray core facility of University of Michigan .
Project description:ATFS-1 has been shown to regulate transcription of mitochondrial chaperone genes such as mtHsp70/hsp-6 and hsp-60 in response to mitocondrial stress. To identify the entire ATFS-1-mediated response, we compared the transcript profiles from wild-type and atfs-1(tm4525) worms raised in the absence and presence of mitochondrial stress. We used microarrays to identify genes regulated by ATFS-1 during mitochondrial stress RNA samples were prepared from wild-type(wt) and atfs-1(tm4525)(mutant) worms fed either control(RNAi) or spg-7(RNAi). Worms were synchronized by bleaching, raised in liquid culture and harvested at the L4 stage. Control is denoted as C and spg-7 treatment is denoted T. Each experiment was performed in triplicate indicated as 1,2 and 3.
Project description:Readthrough into the 3′ untranslated region (3′UTR) of the mRNA results in the production of aberrant proteins. Metazoans efficiently clear readthrough proteins, but the underlying mechanisms remain unknown. Here, we show in C. elegans and mammalian cells that readthrough proteins are targeted by a coupled, two-level quality control pathway involving the BAG6 chaperone complex and the ribosome collision-sensing protein GCN1. Readthrough proteins with hydrophobic C-terminal extensions are recognized by SGTA-BAG6 and ubiquitylated by RNF126 for proteasomal degradation. Additionally, cotranslational mRNA decay initiated by GCN1 and CCR4/NOT limits the accumulation of readthrough products. Unexpectedly, selective ribosome profiling uncovered a general role of GCN1 in regulating translation dynamics when ribosomes encounter nonoptimal codons, a feature of 3′UTR sequences. Dysfunction of GCN1 results in mRNA and proteome imbalance, increasingly perturbing transmembrane proteins and collagens during aging. These results define GCN1 as a key factor acting during translation in maintaining protein homeostasis.
Project description:Genome-wide expression analysis in C. Elegans grown in axenic media with low to toxic selenium concentrations We performed Affymetrix micorarray-based transcriptional profiling on wild-type C. Elegans Bristol N2 grown in low Se axenic media supplemented with five concentrations of selenium, from low to toxic, and harvested at the L4-larva stage. RNA was prepared for hybridization to Affy microarrays from synchronized cultures of wild-type C. elegans seeded in low Se axenic media, supplemented with graded 0, 0.05, 0.1, 0.2, and 0.4 mM Se added as sodium selenite, and harvested at the L4-larva stage (1 culture/sample per Se concentgration).
Project description:We applied a middle-down proteomics strategy for large scale protein analysis during in vivo development of Caenorhabditis elegans. We characterized post-translational modifications (PTMs) on histone H3 N-terminal tails at eight time points during the C. elegans lifecycle, including embryo, larval stages (L1 to L4), dauer and L1/L4 post dauer. Histones were analyzed by our optimized middle-down protein sequencing platform using high mass accuracy tandem mass spectrometry. This allows quantification of intact histone tails and detailed characterization of distinct histone tails carrying co-occurring PTMs. We measured temporally distinct combinatorial PTM profiles during C. elegans development. We show that the doubly modified form H3K23me3K27me3, which is rare or non-existent in mammals, is the most abundant PTM in all stages of C. elegans lifecycle. The abundance of H3K23me3 increased during development and it was mutually exclusive of the active marks H3K18ac, R26me1 and R40me1, suggesting a role for H3K23me3 in to silent chromatin. We observed distinct PTM profiles for normal L1 larvae and for L1-post dauer larvae, or L4 and L4 post-dauer, suggesting that histone PTMs mediate an epigenetic memory that is transmitted during dauer formation. Collectively, our data describe the dynamics of histone H3 combinatorial code during C. elegans lifecycle and demonstrate the feasibility of using middle-down proteomics to study in vivo development of multicellular organisms.
Project description:We used next generation sequensing to determine C.elegans genes induced by Nitroc Oxide (NO) treatment Compare expression profile of NO treated and untreated control.
Project description:Recent work has shown that small non-coding RNAs, including miRNAs, serve an important role in controlling gene expression during development and disease. However, little detailed information exists concerning the relative expression patterns of small RNAs during development of C. elegans. Here we use recent advances in high-throughput sequencing technology to show that expression of non-coding small RNAs, including miRNAs, changes dynamically during development and in the different sexes of C. elegans; approximately 16% of known miRNAs changed over 10 fold in expression during C. elegans development and about 12% of miRNAs showed major changes in expression between males and hermaphrodites of C. elegans. These results should lead to a better understanding of the expression and function of small RNAs in C. elegans development. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Examination of small RNA expression in six different developmental stages of hermaphrodites (Embryo, mid-L1, mid-L2, mid-L3, mid-L4, young adult), and young adult males (dpy-28;him-8) and spermatogenesis-defective young adult hermaphrodites (spe-9). The number of sequence reads for miRNA was assessed from the raw sequence data from Solexa sequencing using perfect sequence matching to known miRNAs (miRBase Release 11.0).
Project description:Effective toxicological testing of the vast number of new and existing chemicals currently in use will require efficient and cost effective methods. We evaluated the utility of a simple, low cost toxicity testing system employing the nematode Caenorhabditis elegans to identify toxicologically relevant changes in gene expression. The objective of this research is to determine genomic and proteomic responses in the model nematode C. elegans to exposures to representatives of several classes of toxic industrial chemicals/materials (TICs/TIMs). A total of 3 chemicals (acrylamide, cadmium chloride, and mercuric chloride) were used in these experiments. Affymetrix GeneChip for C. elegans was used to examine genome-wide responses in the 19,000+ genes of this model organism. Mid-vulval L4 worms were exposed to one of four concentrations of acrylamide, cadmium or mercury for 4h and 8h. Exposures were performed in triplicate.
Project description:Spatiotemporal control of gene expression is crucial for development and subject to evolutionary changes. Although proteins are the final product of most genes, the developmental proteome of an animal has not yet been comprehensively defined, and the correlation between RNA and protein abundance during development is largely unknown. Here, we globally measured and compared protein and mRNA expression changes during the life cycle of the nematodes C. elegans and C. briggsae, separated by ~30 million years of evolution. We observed that developmental mRNA and protein changes were highly conserved, to a surprisingly similar degree, but poorly correlated within a species, suggesting important and widespread post-transcriptional regulation. Post-transcriptional control was particularly well conserved if mRNA fold changes were buffered on the protein level, indicating a predominant repressive function. Finally, among divergently expressed genes, we identified insulin signaling, a pathway involved in life span determination, as a putative target of adaptive evolution. Samples of C. elegans and C. briggsae were collected at major developmental stages throughout the nematode life cycle. These stages comprise a population of mixed embryonic stages (E), populations of all four larval stages (L1, L2, L3, L4), late L4 larvae (LL4), young adults (YA), and a reference sample consisting of a mixture of all stages. To obtain synchronized worm populations, embryos were extracted by bleaching gravid adults and synchronized by starvation. Later stages were picked at fixed timepoints after determining the developmental stages by microscopic observation. For all stages, at least a single poly(A)-extracted mRNA library was sequenced on a single lane of an Illumina Genome Analyzer IIx.
Project description:AMPK (AAK-2) and calcineurin (TAX-6) mediate longevity exclusively through post-translational modification of CRTC-1, the sole C. elegans CRTC (CREB regulated transcriptional coactivator). We performed microarrays to examine the transcriptional responses elicited by the pro-longevity: activation of AMPK, deactivation of calcineurin, and decrease of CREB (CRH-1) activity. Gene expression profiles for crh1 (nn3315) and tax-6 (ok2065) mutants, aak-2c (aa1-321) overexpressers and WT (N2) controls were obtained by measuring RNA levels in replicate pools of 3000 synchronized L4 worms. Three replicate pools of each strain were prepared on separate days.