Showing papers by "Kevin L. Gunderson published in 2014"

Haplotype-resolved whole-genome sequencing by contiguity-preserving transposition and combinatorial indexing

Abstract: Haplotype-resolved genome sequencing enables the accurate interpretation of medically relevant genetic variation, deep inferences regarding population history and non-invasive prediction of fetal genomes. We describe an approach for genome-wide haplotyping based on contiguity-preserving transposition (CPT-seq) and combinatorial indexing. Tn5 transposition is used to modify DNA with adaptor and index sequences while preserving contiguity. After DNA dilution and compartmentalization, the transposase is removed, resolving the DNA into individually indexed libraries. The libraries in each compartment, enriched for neighboring genomic elements, are further indexed via PCR. Combinatorial 96-plex indexing at both the transposition and PCR stage enables the construction of phased synthetic reads from each of the nearly 10,000 'virtual compartments'. We demonstrate the feasibility of this method by assembling >95% of the heterozygous variants in a human genome into long, accurate haplotype blocks (N50 = 1.4-2.3 Mb). The rapid, scalable and cost-effective workflow could enable haplotype resolution to become routine in human genome sequencing.

In vitro, long-range sequence information for de novo genome assembly via transposase contiguity

Abstract: .We describe a method that exploits contiguity preserving transposase sequencing (CPT-seq) to facilitate the scaffolding of de novo genome assemblies. CPT-seq is an entirely in vitro means of generating libraries comprised of 9216 indexed pools, each of which contains thousands of sparsely sequenced long fragments ranging from 5 kilobases to >1 megabase. These pools are ‘‘subhaploid,’’ in that the lengths of fragments contained in each pool sums to ~5% to 10% of the full genome. The scaffolding approach described here, termed fragScaff, leverages coincidences between the content of different pools as a source of contiguity information. Specifically, CPT-seq data is mapped to a de novo genome assembly, followed by the identification of pairs of contigs or scaffolds whose ends disproportionately co-occur in the same indexed pools, consistent with true adjacency in the genome. Such candidate ‘‘joins’’ are used to construct a graph, which is then resolved by a minimum spanning tree. As a proof-of-concept, we apply CPT-seq and fragScaff to substantially boost the contiguity of de novo assemblies of the human, mouse, and fly genomes, increasing the scaffold N50 of de novo assemblies by eight- to 57-fold with high accuracy. We also demonstrate that fragScaff is complementary to Hi-C-based contact probability maps, providing midrange contiguity to support robust, accurate chromosome-scale de novo genome assemblies without the need for laborious in vivo cloning steps. Finally, we demonstrate CPT-seq as a means of anchoring unplaced novel human contigs to the reference genome as well as for detecting misassembled sequences.

Preserving genomic connectivity information in fragmented genomic dna samples

Abstract: A method of sequencing a target nucleic acid polymer by (a) modifying a target nucleic acid polymer to produce a modified nucleic acid polymer; (b) producing fragments of the modified nucleic acid polymer, wherein the fragments are attached to locations on a solid support surface (c) determining nucleotide sequences from the fragments at the locations; and (d) producing a representation of the nucleotide sequence for the target nucleic acid polymer based on the nucleotide sequences from the fragments and the relative distances between the locations on the solid support surface.

Super resolution imaging

Abstract: A detection apparatus that includes (a) an array of responsive pads on a substrate surface; (b) an array of pixels, wherein each pixel in the array has a detection zone on the surface that includes a subset of at least two of the pads; and (c) an activation circuit to apply a force at a first and second pad in the subset, wherein the activation circuit is configured to apply a different force at the first pad compared to the second pad, and wherein the activation circuit has a switch to selectively alter the force at the first pad and the second pad.

Mobile genetic elements and genome evolution 2014.

Abstract: The Mobile Genetic Elements and Genome Evolution conference was hosted by Keystone Symposia in Santa Fe, NM USA, 9 March through 14 March 2014. The goal of this conference was to bring together scientists from around the world who study transposable elements in diverse organisms and researchers who study the impact these elements have on genome evolution. The meeting included over 200 scientists who participated through poster presentations, short talks selected from abstracts, and invited speakers. The talks were organized into eight sessions and two workshops. The topics varied from diverse mechanisms of mobilization to the evolution of genomes and their defense strategies against transposable elements.

Compositions et procédés de séquençage de polynucléotides

Abstract: L'invention concerne des procedes et des compositions pour caracteriser un polynucleotide cible, notamment pour caracteriser la sequence du polynucleotide cible, par des etapes de translocation fractionnee utilisant une Hel308 helicase de la translocation du polynucleotide cible a travers un pore.