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: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.
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. In total, 14 dual-color microarrays were done on two wild type strains (N2 and CB4856) and three age groups (40, 96, and 214 hours). 5 replicates of t1 (juvenile) and t3 (senescent) samples, and 4 replicates of t2 (reproductive) samples, in a dye-swap design.
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.