KEGG(Kyoto Encyclopedia of Genes and Genomes)〔和文〕 (特集 ゲノム医学の現在と未来--基礎と臨床) -- (データベース)

Genomes assembled de novo from short reads are highly fragmented relative to the finished chromosomes of Homo sapiens and key model organisms generated by the Human Genome Project. To address this problem, we need scalable, cost-effective methods to obtain assemblies with chromosome-scale contiguity. Here we show that genome-wide chromatin interaction data sets, such as those generated by Hi-C, are a rich source of long-range information for assigning, ordering and orienting genomic sequences to chromosomes, including across centromeres. To exploit this finding, we developed an algorithm that uses Hi-C data for ultra-long-range scaffolding of de novo genome assemblies. We demonstrate the approach by combining shotgun fragment and short jump mate-pair sequences with Hi-C data to generate chromosome-scale de novo assemblies of the human, mouse and Drosophila genomes, achieving--for the human genome--98% accuracy in assigning scaffolds to chromosome groups and 99% accuracy in ordering and orienting scaffolds within chromosome groups. Hi-C data can also be used to validate chromosomal translocations in cancer genomes.

/pdf/chromosome-scale-scaffolding-of-de-novo-genome-assemblies-2ehq9rw9bn.pdf

Chromosome-scale scaffolding of de novo genome assemblies based on chromatin interactions

High-throughput sequencing technologies are revolutionizing the life sciences. The past 12 months have seen a burst of genome sequences from non-model organisms, in each case representing a fundamental source of data of significant importance to biological research. This has bearing on several aspects of evolutionary biology, and we are now beginning to see patterns emerging from these studies. These include significant heterogeneity in the rate of recombination that affects adaptive evolution and base composition, the role of population size in adaptive evolution, and the importance of expansion of gene families in lineage-specific adaptation. Moreover, resequencing of population samples (population genomics) has enabled the identification of the genetic basis of critical phenotypes and cast light on the landscape of genomic divergence during speciation.

https://www.cell.com/trends/ecology-evolution/pdf/S0169-5347(13)00231-0.pdf

Genome sequencing and population genomics in non-model organisms.

Adam Phillippy, Curtis Van Tassell, Timothy Smith and colleagues present a new reference genome assembly for the domestic goat using a pipeline that improves contiguity of the assembly by more than 250-fold. The pipeline uses a combination of short- and long-read sequencing, optical mapping, and chromatin interaction mapping.

/pdf/single-molecule-sequencing-and-chromatin-conformation-2m8jv7uj4x.pdf

Single-molecule sequencing and chromatin conformation capture enable de novo reference assembly of the domestic goat genome

Long-read sequencing and novel long-range assays have revolutionized de novo genome assembly by automating the reconstruction of reference-quality genomes. In particular, Hi-C sequencing is becoming an economical method for generating chromosome-scale scaffolds. Despite its increasing popularity, there are limited open-source tools available. Errors, particularly inversions and fusions across chromosomes, remain higher than alternate scaffolding technologies. We present a novel open-source Hi-C scaffolder that does not require an a priori estimate of chromosome number and minimizes errors by scaffolding with the assistance of an assembly graph. We demonstrate higher accuracy than the state-of-the-art methods across a variety of Hi-C library preparations and input assembly sizes. The Python and C++ code for our method is openly available at https://github.com/machinegun/SALSA.

/pdf/integrating-hi-c-links-with-assembly-graphs-for-chromosome-2cupam0zhh.pdf

Integrating Hi-C links with assembly graphs for chromosome-scale assembly.

An instrument for whole-genome optical mapping is used to assemble the genome of the domestic goat into super-long scaffolds.

/pdf/sequencing-and-automated-whole-genome-optical-mapping-of-the-3eistsjxpu.pdf

Rich Moore

Papers

Sequencing and automated whole-genome optical mapping of the genome of a domestic goat (Capra hircus)