Project description:The aims of our study were: 1) to elucidate physiological responses in three Miscanthus species and newly bred triploid hybrid in three water stress treatment conditions 2) utilise the induced physiological conditions for an in-depth transcriptome study on the molecular basis of water stress in Miscanthus spp.
Project description:Small RNAs (21-24 nt) are pivotal regulators of gene expression that guide both transcriptional and post-transcriptional silencing mechanisms in diverse eukaryotes, including most if not all plants. MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are the two major types, both of which have a demonstrated and important role in plant development, stress responses and pathogen resistance. In this work, we used a deep sequencing approach (Sequencing-By-Synthesis, or SBS) to develop sequence resources of small RNAs from different Miscanthus x giganteus tissues (including leaves, flowers, and rhizomes). The high depth of the resulting datasets enabled us to examine in detail critical small RNA features such as size distribution, tissue-specific regulation and sequence conservation between different organs in this species. We also developed database resources and a dedicated website (http://smallrna.udel.edu/) with computational tools for allowing other users to identify new miRNAs or siRNAs involved in specific regulatory pathways, verify the degree of conservation of these sequences in other plant species and map small RNAs on genes or larger regions of the genome under study.
Project description:Small RNAs (21-24 nt) are pivotal regulators of gene expression that guide both transcriptional and post-transcriptional silencing mechanisms in diverse eukaryotes, including most if not all plants. MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are the two major types, both of which have a demonstrated and important role in plant development, stress responses and pathogen resistance. In this work, we used a deep sequencing approach (Sequencing-By-Synthesis, or SBS) to develop sequence resources of small RNAs from different Miscanthus x giganteus tissues (including leaves, flowers, and rhizomes). The high depth of the resulting datasets enabled us to examine in detail critical small RNA features such as size distribution, tissue-specific regulation and sequence conservation between different organs in this species. We also developed database resources and a dedicated website (http://smallrna.udel.edu/) with computational tools for allowing other users to identify new miRNAs or siRNAs involved in specific regulatory pathways, verify the degree of conservation of these sequences in other plant species and map small RNAs on genes or larger regions of the genome under study. Small RNA libraries were derived from leaves, flowers and rhizomes of Miscanthus x giganteus. Each tissue represented a mixture of developmental stages, with a bias towards those from early, actively differentiating cells. For rhizomes, the apical tip portion was collected. Total RNA was isolated using the Plant RNA Purification Reagent (Invitrogen) and submitted to Illumina (Hayward, CA, http://www.illumina.com) for small RNA library construction using approaches described in (Lu et al., 2007) with minor modifications. The small RNA libraries were sequenced with the Sequencing-By-Synthesis (SBS) technology by Illumina. PERL scripts were designed to remove the adapter sequences and determine the abundance of each distinct small RNA. We thank Steven Moose for providing the plant material and Kan Nobuta for assistance with the computational methods.
Project description:To test if scRNA-seq contains sufficient phylogenetic information to reconstruct a population history of cancer, immunosuppressed NU/J mice were injected with human cancer cells (MDA-MB-231-LM2). The tumors that develop are derived from the same population and thus share a common ancestor, but evolved independently in each mouse and should form separate clades on reconstructed phylogenetic trees when analysed together. We explore and compare results of phylogenetic analyses based on both expression levels and SNVs called from our scRNA-seq data. Both techniques are shown to be useful for reconstructing phylogenetic relationships between cells, refecting the clonal composition of a tumor. Without an explicit error model, standardized expression values appears to be more powerful and informative than the SNV values at a lower computational cost, due to being a by-product of standard expression analysis. Our results suggest that scRNA-seq can be a competitive alternative or useful addition to conventional scDNA-seq phylogenetic reconstruction. Our results open up a new direction of somatic phylogenetics based on scRNA-seq data. Further research is required to refne and improve these approaches to capture the full picture of somatic evolutionary dynamics in cancer.