Project description:Whole-genome re-sequencing of the wild isolate PB306 (Caenorhabditis elegans nematode) and three derived Mutation Accumulation Lines
| PRJEB30822 | ENA
Project description:Epimutations in Caenorhabditis elegans mutation accumulation lines
Project description:To gain mechanistic insights into the molecular changes of Caenorhabditis briggsae between the two developmental stages: embryo and larvae
Project description:Different populations of the same species survive different environments through local adaptation. Temperature is one of the most important driving forces that could result in local adaptation. Here, we studied the influence of extreme low temperature on the survival of two genetically and geographically distinct populations of the free-living Caenorhabditis briggsae. We found that Caenorhabditis briggsae strains of temperate origin had a cold resistant phenotype, while those originating from a tropical climate had reduced survival after cold treatment. Using this phenotypic difference between geographically diverse populations as a model for how species adapt to their local environment, we then analyzed the transcriptional profiles of two Caenorhabditis briggsae strains of tropical and temperate origin to find genes that are involved in survival after extreme cold. In summary, the response to the extreme low temperature that clearly distinguishes the temperate and tropical Caenorhabditis briggsae strains could serve as an excellent example for studying local adaption of species that show genetic separation associated with their geographical distribution.
Project description:Whole-genome re-sequencing of the reference strain N2 (Caenorhabditis elegans nematode) and one derived Mutation Accumulation Line.
Project description:The nematode Caenorhabditis elegans contains each of the broad classes of eukaryotic small RNAs, including microRNAs (miRNAs), endogenous small-interfering RNAs (endo-siRNAs) and piwi-interacting RNAs (piRNAs). To better understand the evolution of these regulatory RNAs, we deep sequenced small RNAs from C. elegans and three closely related nematodes: C. briggsae, C. remanei and C. brenneri. The results reveal a fluid landscape of small RNA pathways with essentially no conservation of individual sequences aside from a subset of miRNAs. We identified 52 miRNA families that are conserved in each of the four species as well as numerous miRNAs that are species specific or shared between only two or three species. Despite a lack of conservation of individual piRNAs and siRNAs many of the features of each pathway, including genomic distribution, are conserved. We show that in each species, 26G siRNAs trigger stage-specific secondary siRNA formation. We also observe that piRNAs trigger siRNA formation from targets containing up to three mismatches in each species. Finally, we show that nematodes produce two distinct sex-specific classes of piRNAs, suggesting different roles for piRNAs in male and female germlines. Sequencing small RNAs from four Caenorhabditis species: C. elegans, C. briggsae, C. remanei and C. brenneri