Project description:This experiment investigates the gene expression differences upon Orsay virus infection in the Caenorhabdits elegans strains N2 and CB4856. Assays measuring viral load found that the N2 strain displays higher viral loads upon infection than the CB4856 strain. The goal of the experiment was to identify gene-expression differences that could explain the differences in viral load. We (mock-)infected 26h-old C. elegans populations with Orsay virus and took samples after 30h of infection. For each treatment-strain combination 8 samples were collected. Thereafter RNA was isolated, labelled, and hybridized on microarray.
Project description:Natural genetic variation is the raw material of evolution and influences disease development and progression. To analyze the effect of the genetic background on protein expression in the nematode C. elegans (Caenorhabditis elegans), the two genetically highly divergent wild-type strains N2 (Bristol) and CB4856 (Hawaii) were compared quantitatively. In total, we quantified 3,238 unique proteins in three independent SILAC (stable isotope labeling by amino acids in cell culture) experiments. The differentially expressed proteins were enriched for genes that function in insulin-signaling and stress response pathways.
Project description:Background: Copy number variation is an important component of genetic variation in higher eukaryotes. The extent of natural copy number variation in C. elegans is unknown outside of 2 highly divergent wild isolates and the canonical N2 Bristol strain. Results: We have used array comparative genomic hybridization (aCGH) to detect copy number variation in the genomes of 12 natural isolates of Caenorhabditis elegans. Deletions relative to the canonical N2 strain are more common in these isolates than duplications, and indels are enriched in multigene families on the autosome arms. Among the strains in our study, the Hawaiian and Madeiran strains (CB4856 and JU258) carry the largest number of deletions, followed by the Vancouver strain (KR314). Overall we detected 510 different deletions affecting 1136 genes, or over 5% of the genes in the canonical N2 genome. The indels we identified had a median length of 2.7 kb. Since many deletions are found in multiple isolates, deletion loci were used as markers to derive an unrooted tree to estimate genetic relatedness among the strains. Conclusion: Copy number variation is extensive in C. elegans, affecting over 5% of the genes in the genome. The deletions we have detected in natural isolates of C. elegans contribute significantly to the number of deletion alleles available to researchers. The relationships between strains are complex and different regions of the genome possess different genealogies due to recombination throughout the natural history of the species, which may not be apparent in studies utilizing smaller numbers of genetic markers. Twelve C. elegans natural isolate samples were studied. There were no replicates or dye-swap hybridizations.
Project description:We conducted an experiment on introgression lines of Caenorhabditis elegans derived from a NL5901 cross with three previously constructed CB4856>N2 ILs (WN268, WN269, and WN270). The tested ILs carry a combination of chromosome V introgressions and the alpha-synuclein trans-gene: CB4856>N2 / aS, CB4856>N2 / -, - / aS, and - / -. We grew synchronized populations of the nematodes (12 ILs, N2, CB4856, NL5901, and SCH4856) under normal conditions (20 degrees Celcius, feeding on Escherichia coli OP50) for 120 hours. This experiment was repeated three times. The goal of the experiment was to identify loci affecting gene expression in the presence of human alpha-synuclein
Project description:We analyzed the consequences of recombination in gene expression. For this, we measured expression patterns in two C. elegans wild types, N2 and CB4856 (CB). We compare these profiles with gene expression values from a Recombinant Inbred Population (RIL) derived from the same wild types. Expression values of the RILs (GSE17071) were obtained from Viñuela et al. (Genome Research, 2010). N2 and CB strain nematodes were cultured in identical conditions. Likewise, mRNA was extracted at three different ages (juveniles, reproductive and old worms) to investigate the transcriptional consequences of recombination in aging worms. Then, we explored gene expression heritability and transgression as genetic parameters for the analysis of gene expression divergence in natural isolates. Moreover, we investigated the progression of those parameters with age.