Project description:Transposon insertion site sequencing (TIS) is a powerful method for associating genotype to phenotype. However, all TIS methods described to date use short nucleotide sequence reads which cannot uniquely determine the locations of transposon insertions within repeating genomic sequences where the repeat units are longer than the sequence read length. To overcome this limitation, we have developed a TIS method using Oxford Nanopore sequencing technology that generates and uses long nucleotide sequence reads; we have called this method LoRTIS (Long Read Transposon Insertion-site Sequencing). This experiment data contains sequence files generated using Nanopore and Illumina platforms. Biotin1308.fastq.gz and Biotin2508.fastq.gz are fastq files generated from nanopore technology. Rep1-Tn.fastq.gz and Rep1-Tn.fastq.gz are fastq files generated using Illumina platform. In this study, we have compared the efficiency of two methods in identification of transposon insertion sites.
Project description:We have developed a microarray intended for use in finding all transposons in a region of interest. By selectively amplifying and hybridizing transposon flanking DNA to our array, we can localize all transposons in the region present on our TIP-chip, a dense tiling array. We have tested our technology in yeast and have been successful. Keywords: transposon insertion profiling, genomic DNA, yeast
Project description:We have developed a microarray intended for use in finding all transposons in a region of interest. By selectively amplifying and hybridizing transposon flanking DNA to our array, we can localize all transposons in the region present on our TIP-chip, a dense tiling array. We have tested our technology in yeast and have been successful. The two FY2 hybridizations are technical replicates and serve as a benchmark -- we compared these results to the published S288C sequence. The two GRF167 samples are also technical replicates and these are the base strain for the L27-10 hybridizations, and therefore serve as controls for those hybridizations. The three L27-10 hybridizations are all technical replicates.
Project description:Streptococcus pneumoniae is a major cause of serious infections such as pneumonia and meningitis in both children and adults worldwide. Here, we describe the development of a high-throughput genome-wide technique, Genomic Array Footprinting (GAF), for the identification of genes essential for this bacterium at various stages during infection. GAF enables negative screens by means of a combination of transposon mutagenesis and microarray technology for the detection of transposon insertion sites. We tested several methods for the identification of transposon insertion sites and found that amplification of DNA adjacent to the insertion site by PCR resulted in non-reproducible results, even when combined with an adapter. However, restriction of genomic DNA followed directly by in vitro transcription circumvented these problems. Analysis of parallel reactions generated with this method on a large mariner transposon library, showed that it was highly reproducible and correctly identified essential genes. Comparison of a mariner library to one generated with the in vivo transposition plasmid pGh:ISS1, showed that both have an equal degree of saturation, but that 9% of the genome is preferentially mutated by either one. The usefulness of GAF was demonstrated in a screen for genes essential for survival of zinc stress. This identified a gene encoding a putative cation efflux transporter, and its deletion resulted in an inability to grow under high zinc conditions. In conclusion, we developed a fast, versatile, specific, and high-throughput method for the identification of conditionally essential genes in S. pneumoniae. Keywords: GAF Identification of transposon insertion sites
Project description:This study was aimed to do genome-wide identification of fitness factors of ExPEC using an mouse infection model. A transposon (Tn) mutagenesis library (input) containing insertions of 72% of the total chromomose encoded genes was used to infect mouse. Bacteria were then recovered from the brain, lung, and spleen (output libraries) at 12 hours post infection. The genomic DNA was extracted from the input and the output libraries. The genomic fragment flanking the transposon was enriched by PCR which was then sequenced by Illumina sequencing. The insertion sites were then mapped to the genome of ExPEC PCN033 strain to identify differentially depleted genes which are genes potentially involved in fitness during infection.
Project description:Transposon screens are powerful in vivo assays used to identify loci driving carcinogenesis. These loci are identified as Common Insertion Sites (CIS), i.e. regions with more transposon insertions than expected by chance. However, the identification of CIS is strongly affected by biases in the insertion behaviour of transposon systems. Here, we introduce Transmicron, a novel method that differs from previous methods by i) modelling neutral insertion rates based on chromatin accessibility, transcriptional activity, and sequence context, and ii) estimating oncogenic selection for each genomic region using Poisson regression to model insertion counts while controlling for neutral insertion rates. To assess the benefits of our approach, we generated a dataset applying two different transposon systems under comparable conditions. Benchmarking for enrichment of known cancer genes showed improved performance of Transmicron against state-of-the-art methods. Modelling neutral insertion rates allowed for better control of false positives and stronger agreement of the results between transposon systems. Moreover, using Poisson regression to consider intra-sample and inter-sample information proved beneficial in small and moderately-sized datasets. Transmicron is open-source and freely available. Overall, this study contributes to the understanding of transposon biology and introduces a novel approach to use this knowledge for discovering cancer driver genes.
Project description:We have developed two methods for efficiently consructing RNA-seq libraries using transposition. Each method constructs high quality RNA-seq libraries when compared to standard approaches. One of the methods (Directional Tn-RNA-seq) maintains strand-of-origin information and exhibits strand specificity comparable to current approaches. RNA-seq libraries were constructed from ECC-1, a human cell line, and Universal Human Reference RNA using transposon-based and standard RNA-seq library construciton methods.