Genome assembly algorithms articles within Nature Communications

Genomes usually contain multiple chromosomes. The paper reports on GALA, a computational framework for chromosome-based sequencing data separation and gap-free de novo assembly. It allows integration of different sources of data.

H37Rv is the most widely used Mycobacterium tuberculosis strain, and its genome is the reference sequence for this pathogen. Here, Chitale et al. present a bioinformatic pipeline for accurate assembly of bacterial genome sequences, and use it to provide important updates to the M. tuberculosis reference genome.

Consensus sequence-based methods for self-correction of long-read sequencing data are affected by biases that can mask true variants characterizing little-covered or low-frequency haplotypes. Here, to address this issue, the authors develop a variation graph-based method for performing haplotype-aware self-correction of long reads.

Reference genomes for gut microbiomes help unravel microbial “dark matter” and serve as valuable resource for disease-focused studies. Here, the authors perform short and long read metagenomics and metagenome-assembled genomes analyses to profile the gut microbiome of Southeast Asian populations, revealing significant species and strain-level diversity, with thousands of previously uncharacterized biosynthetic gene clusters.

Human pan-genomics are increasing our knowledge of genomic diversity and genetic factors in disease. Here, the authors built a gastric cancer pan-genome that included the sequences of Chinese Han patients, and predicted putative and previously unaligned genes associated with gastric cancer.

Pangenomes have a number of advantages over linear reference assemblies. Here the authors use bovine haplotype-resolved assemblies to show that structural variant-based pangenomes are consistent regardless of sequence platform, assembler, or coverage, suggesting that rigid protocols may not be required.

The role of genome folding in the heritability and evolvability of structural variations is not well understood. Here the authors investigate the impact of the three-dimensional genome topology of germ cells in the formation and transmission of gross structural genomic changes detected from comparing whole-genome sequences of 14 rodent species.

Here, Johansen et al. develop an approach, Phages from Metagenomics Binning (PHAMB), that allows the binning of thousands of viral genomes directly from bulk metagenomics data, while simultaneously enabling clustering of viral genomes into accurate taxonomic viral populations, unveiling viral-microbial host interactions in the gut.

Existing long-read de novo assembly methods can partially, but not completely, separate strains. Here, the authors develop Strainberry, a metagenome assembly bioinformatic pipeline that exclusively uses longread data to accurately separate and reconstruct strain genomes from single-sample low-complexity microbiomes.

Methods to produce haplotype-resolved genome assemblies often rely on access to family trios. The authors present FALCON-Phase, a tool that combines ultra-long range Hi-C chromatin interaction data with a long read de novo assembly to extend haplotype phasing to the contig or scaffold level.

The cost and complexity of whole genome sequencing limits its use in identifying and validating sequences used for genetic engineering and synthetic biology. Here the authors present Prymetime, an integrated workflow to sequence engineered strains and identify engineering in metagenomes.

Genome assembly approaches are limited by factors including cost, power and incomplete resolution. Here, the authors present Aquila, a method that uses a reference sequence and linked read data to generate high quality diploid genome assemblies from which genetic variation can be detected and phased.

Human reference genomes are typically constructed from few individuals, and are biased towards European and African genomes. Here, the authors assemble three Japanese genomes to create a population-specific reference genome. They then demonstrate improved variant calling from exome sequencing with this reference genome.

Nanopore reads have been advantageous for de novo genome assembly; however these reads have high error rates. Here, the authors develop an error correction and de novo assembly tool, NECAT, which produces efficient, high quality assemblies of nanopore reads.

Accurate, phased assemblies are a key tool in understanding the human genome, particularly in highly polymorphic regions like the medically important MHC. Here the authors provide an assembly-based benchmark for this difficult-to-characterize region.

Haplotype reconstruction of distant genetic variants is problematic in short-read sequencing. Here, the authors describe HapTree-X, a probabilistic framework that uses differential allele-specific expression to better reconstruct paternal haplotypes from diploid and polyploid genomes.

Sequence depth and read length determine the quality of genome assembly. Here, the authors leverage a set of PacBio reads to develop guidelines for sequencing and assembly of complex plant genomes in order to allocate finite resources using maize as an example.

Repetitive sequences in complex eukaryote genomes can cause fragmented assemblies with incomplete gene sequences and unanchored or mispositioned contigs. Here, the authors report HERA, a method to improve genome assemblies by efficiently resolving repeats using single-molecule sequencing data.

Most phasing programmes for sequencing data work well for genomes with low heterozygosity but drop in performance in regions of high heterozygosity. Here, Kajitani et al. develop the assembler Platanus-allee and demonstrate its utility in de novo assemblies of various genomes and the human MHC region.

Due to various structural and sequence complexities, the human Y chromosome is challenging to sequence and characterize. Here, the authors develop a strategy to sequence native, unamplified flow sorted Y chromosomes with a nanopore sequencing platform, and report the first assembly of a human Y chromosome of African origin.

The evolution and genetic nature of metastatic lesions is not completely characterized. Here the authors perform a comprehensive whole-genome study of colorectal metastases in comparison to matched primary tumors and define a multistage progression model and metastasis-specific changes that, in part, are therapeutically actionable.

The majority of the human reference genome assembly is represented as a single consensus haplotype. Here, Wong et al. analyze de novo assemblies of 17 diverse, haplotype-resolved genomes to gain insights into the structure of genetic diversity and compile a list of alternative haplotypes across populations.

High-quality reference genomes facilitate analysis of genome structure and variation. Here Duet al. create a near-complete assembly of the indicarice genome by combining single molecule sequencing with mapping data and fosmid sequences and identify genetic variants by comparison with other rice genomes.

Genome assembly for many plant species can be challenging due to large size and high repeat content. Here, the authors usein vitroproximity ligation to assemble the genome of lettuce, revealing a family-specific triplication event and providing a comprehensive reference genome for a member of the Compositae.

Assembling genomes using currently available computational methods can be time consuming. Here, Coin and colleagues describe a bioinformatics tool named npScarf that can scaffold and complete an existing short read assembly in real-time using nanopore sequencing.

Currently available metagenomic data analysis relies on reference genomes. Here, the authors describe a newde novometagenomic assembly method, metaSort, that constructs bacterial genomes from metagenomic samples to reduce microbial community complexity while increasing genome recovery and assembly.

The correct assembly of genomes from sequencing data remains a challenge due to difficulties in correctly assigning the location of repeated DNA elements. Here the authors describe GRAAL, an algorithm that utilizes genome-wide chromosome contact data within a probabilistic framework to produce accurate genome assemblies.