Project description:Transcriptional profiling of N2 (WT) and miR-85(m4117) Caenorhabditis elegans at larval stage 4 (L4) compared at either control temperature (20°C) or after 3hr HS (35°C).
Project description:The nematode Caenorhabditis elegans (C. elegans) is often used as a model organism to study cell and developmental biology. Quantitative mass spectrometry has only recently been performed in C. elegans and, so far, most studies have been done on adult worm samples. Here we use quantitative mass spectrometry to characterise protein level changes across the four larval developmental stages (L1-L4) of C. elegans, in biological triplicate. In total, we identify 4,130 proteins and quantify 1,541 proteins that were identified across all four stages in all three biological repeats with at least 2 unique peptides per protein. Using hierarchical clustering and functional ontological analyses, we identify 21 protein groups containing proteins with similar protein profiles across the four stages, and highlight the most overrepresented biological functions in each of these protein clusters. In addition, we use the dataset to identify putative larval stage specific proteins in each individual developmental stage, as well as in the early and late developmental stages. In summary, this dataset provides a system-wide analysis of protein level changes across the four C. elegans larval developmental stages, which serves as a useful resource for the worm development research community.
Project description:In this study, we exposed Caenorhabditis elegans wild types N2 to water collected from six sources in the Dutch village Sneek. The sources were: wastewater from a hospital, a community (80 households), a nursing home, influent into the local municipal wastewater treatment plant, effluent of the wastewater treatment plant, and surface water samples. The goal of the experiment was to determine if C. elegans can be used to identify pollutants in the water by transcriptional profiling. Age synchronized worms at developmental L4 larval stage were exposed to treatment for 24 hours. After flash freezing the samples, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.
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:In this study, we exposed Caenorhabditis elegans wild types N2 to two concentrations of the model genotoxicants formaldehyde (HCHO), N-ethyl-N-nitrosourea (ENU), and methyl methanesulfonate (MMS).We performed a concentration-response test to determine the non-toxic concentration range for studying the transcriptional effects of compounds. In microarray experiments, we studied two concentrations (1 mM and 5 mM) for each compound and a control of M9 medium. Age synchronized worms at developmental L4 larval stage were exposed to treatment for four hours. After flash freezing the samples, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.
Project description:To identify genes differentially expressed during the molt, we collected RNA 30-40 minutes after feeding cessation at the start of the fourth larval stage (L4) lethargus. Additional time points for RNA collection were in the mid-L4 stage, approximately four hours prior to lethargus, and in the young adult stage, four hours after lethargus. These samples were interrogated with the Affymetrix C. elegans Genome Array. A total of 1,804 gene transcripts were up regulated, and 1,088 gene transcripts were down regulated, during the L4 lethargus period compared to the L4 and Adult stages (false discovery rate (FDR) < 0.05).
Project description:In this study, we exposed Caenorhabditis elegans wild types N2 to two concentrations of the model genotoxicants formaldehyde (HCHO), N-ethyl-N-nitrosourea (ENU), and methyl methanesulfonate (MMS).We performed a concentration-response test to determine the non-toxic concentration range for studying the transcriptional effects of compounds. In microarray experiments, we studied two concentrations (1 mM and 5 mM) for each compound and a control of M9 medium. Age synchronized worms at developmental L4 larval stage were exposed to treatment for two hours. After flash freezing the samples, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.
Project description:In this study, we exposed Caenorhabditis elegans wild types N2 to the model indirect-acting toxicants aflatoxin B1 (AFB1), benzo(a)pyrene (B(a)P), the PCB mixture Aroclor 1254 (PCB1254), and 2,3,7,8-tetrachlorodibenzodioxin (TCDD). In microarray experiments, we studied one concentration of AFB1 (30 μM), one concentration of B(a)P (30 μM), two concentrations of PCB1254 (1 μM and 30 μM), and two concentrations of TCDD (1 μM and 10 μM). As a control M9 medium with 0.5% DMSO was used. Age synchronized worms at developmental L4 larval stage were exposed to treatment for 24 hours. After flash freezing the samples, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.
Project description:Cadmium is a naturally occurring heavy metal, and it is widely used in industry. Due to its persistent toxic effect, cadmium is classified as a category one human carcinogen. Its toxicity has been extensively studied in different organisms, including the nematode Caenorhabditis elegans. To investigate the transcriptomic responses following cadmium during early life exposure, C. elegans larval were exposed either from L1 to L3 stage or L1 to L4 stage to 20 µM cadmium chloride. RNAseq was applied to identified the changes of the transcriptome and the pathways which are specific to each stage. Overall, the result revealed that the highest responsive genes in both exposure scenario were linked to oxidative stress, lipid metabolism and ion binding. Additionally, some of these genes are well characterized and linked to specific functions, but some have no known function, however these uncharacterized genes are differentially expressed in both stages as a result of cadmium toxicity.Numerous transcripts were identified in one stage but not at the other. Furthermore, a general trend was observed where a larger number of genes were differentially expressed at L3 stage compared to L4, which suggest stage specific sensitivity in response to cadmium exposure.