Project description:Primary objectives: The primary objective is to investigate circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Primary endpoints: circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Project description:Cytosine methylation is a conserved base modification, but explanations for its interspecific variation remain elusive. Only through taxonomic sampling of disparate groups can unifying explanations for interspecific variation be thoroughly tested. Here we leverage phylogenetic resolution of cytosine DNA methyltransferases (DNA MTases) and genome evolution to better understand widespread interspecific variation across 40 diverse fungal species. DNA MTase genotypes have diversified from the ancestral DNMT1+DNMT5 genotype through numerous loss events, and duplications, whereas, DIM-2 and RID-1 are more recently derived in fungi. Methylation is typically enriched at intergenic regions, which includes repeats and transposons. Unlike certain Insecta and Angiosperm species, Fungi lack canonical gene body methylation. Some fungi species possess large clusters of contiguous methylation encompassing many genes, repetitive DNA and transposons, and are not ancient in origin. Broadly, methylation is partially explained by DNA MTase genotype and repetitive DNA content. Basidiomycota on average have the highest level of methylation, and repeat content, compared to other phyla. However, exceptions exist across Fungi. Other traits, including DNA repair mechanisms, might contribute to interspecific methylation variation within Fungi. Our results show mechanism and genome evolution are unifying explanations for interspecific methylation variation across Fungi.
Project description:Salvia is an important genus from the Lamiaceae with approximately 1000 species distributed globally. Several Salvia species are commercially important because of their medicinal and culinary properties. We report the construction of the first fingerprinting array for Salvia species enriched with polymorphic and divergent DNA sequences and demonstrate the potential of this array for fingerprinting several economically important members of this genus. In order to generate the Salvia Subtracted Diversity Array (SDA), a Suppression Subtractive Hybridization (SSH) was performed between a pool of ten Salvia species and a pool of non-angiosperm and angiosperms (excluding the Lamiaceae) to selectively isolate Salvia-specific sequences. A total of 285 subtracted genomic DNA (gDNA) fragments were amplified and arrayed. DNA fingerprints were obtained for fifteen Salvia genotypes including three that were not part of the original subtraction pool. Hierarchical cluster analysis indicated that the Salvia-specific SDA was capable of differentiating closely related species of S. officinalis and S. miltiorrhiza and was also able to reveal genetic relationships consistent with geographical origins. Species-specific features were also found for S. elegans, S. officinalis, S. sclarea, S. przewalskii and S. runcinata.