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:Many organisms in the nature can drive themselves into an ametabolic state known as anhydrobiosis upon extreme desiccation. The nematode C. elegans is one of them. However, the anhydrobiotic ability of the worm is limited to a special developmental stage known as the dauer. Besides, the dauer larvae must be first treated by a mild desiccation stress (preconditioning) so that they gain desiccation tolerance. In this study, we investigated the differential gene expression during preconditioning in the C. elegans dauer.
Project description:Transcriptional profiling of C. elegans worms from (1) dauer stage, or (2) dauer-exit at 12 hours stage, compared to mix-stage worms as a common reference. The goal was to determine genes regulated during dauer development and recovery or exit from dauer stage. This data was then compared to data generated for corresponding developmental stages in the nematode Pristionchus pacificus (see NCBI GEO series GSE31861) , to study evolution of developmental pathways regulating dauer development.
Project description:These are the 94 microarray experiments that are published in the paper: John Wang and Stuart K. Kim. Global analysis of dauer gene expression in Caenorhabditis elegans, Development 2003 130: 1621-1634. There are 94 individual microarray experiments divided into 3 broad experiments. The first experiment is a time course of dauer exit; each time course is labeled as "Dauer MTC#". The second experiment is a time course of L1 development after starvation arrest; each time couse is labeled "L1 MTC#". The final experiment is a comparison of pure dauers (0 hours) versus 12 hours after dauer exit and are labeled "Dauer Adjust". Every time course was repeated 4 times (#N)however for the dauer 4 and 7 hour time points there are only 3 replicates. For instance, all the time points labeled as "Dauer MTC#1" are from the same starting pool of dauer worms that were aliquoted into 10 fractions and analyzed at the time indicated. Every sample is compared to a common reference RNA that is used throughout all the hybridizations. In some cases there is a "-2" after the hour designation; this means the first hybridization failed for some technical reason and thus the second hybridization (same RNA) is reported. Groups of assays that are related as part of a time series. Keywords: time_series_design
Project description:These are the 94 microarray experiments that are published in the paper: John Wang and Stuart K. Kim. Global analysis of dauer gene expression in Caenorhabditis elegans, Development 2003 130: 1621-1634. There are 94 individual microarray experiments divided into 3 broad experiments. The first experiment is a time course of dauer exit; each time course is labeled as "Dauer MTC#". The second experiment is a time course of L1 development after starvation arrest; each time couse is labeled "L1 MTC#". The final experiment is a comparison of pure dauers (0 hours) versus 12 hours after dauer exit and are labeled "Dauer Adjust". Every time course was repeated 4 times (#N)however for the dauer 4 and 7 hour time points there are only 3 replicates. For instance, all the time points labeled as "Dauer MTC#1" are from the same starting pool of dauer worms that were aliquoted into 10 fractions and analyzed at the time indicated. Every sample is compared to a common reference RNA that is used throughout all the hybridizations. In some cases there is a "-2" after the hour designation; this means the first hybridization failed for some technical reason and thus the second hybridization (same RNA) is reported.
Project description:This SuperSeries is composed of the following subset Series: GSE30977: C. elegans: Dauers and Dauer-Exit at 12 hour time-point vs. Mix-stage worms GSE31861: P. pacificus : Dauers and Dauer-Exit at 12 hour time-point vs. Mix-stage worms Refer to individual Series
Project description:Transcriptional profiling of C. elegans worms from (1) dauer stage, or (2) dauer-exit at 12 hours stage, compared to mix-stage worms as a common reference. The goal was to determine genes regulated during dauer development and recovery or exit from dauer stage. This data was then compared to data generated for corresponding developmental stages in the nematode Pristionchus pacificus (separate data-sets on a custom microarray platform designed by us and manufactured by Agilent) , to study evolution of developmental pathways regulating dauer development. Two-condition experiments. Experiment 1 = Dauers vs. Mix-stage worms. 4 biological replicates for each condition, including 2 dye-swaps. Experiment 2 = Dauer-Exit at 12 hour time-point s vs. Mix-stage worms. 4 biological replicates for each condition, including 2 dye-swaps. Total samples from both experiments 1 and 2 = 8.