Software

AmpliDiff

AmpliDiff is a computational tool for designing amplicons for viral metagenome analysis. AmpliDiff finds amplicons and corresponding primers simultaneously, in order to differentiate maximally between different lineages, strains, or species, as defined by the user. The method is described in our biorxiv preprint.

AmpliDiff is implemented in Python and publicly available on github.

VLQ: Viral Lineage Quantification

VLQ enables fast and accurate SARS-CoV-2 variant prediction from wastewater sequencing data. The approach is based on computational techniques initially used for RNA-Seq quantification (kallisto). All details are described in our Genome Biology paper.

VLQ is implemented in python/bash and publicly available on github. There is also a NextFlow implementation of VLQ.

HaploConduct

HaploConduct is a package designed for reconstruction of individual haplotypes from next generation sequencing data. Currently, HaploConduct consists of two methods: SAVAGE and POLYTE. The complete HaploConduct package is publicly available on github under the GPLv3 license and can be easily installed using the Conda package manager.

SAVAGE: Strain Aware VirAl GEnome assembly

SAVAGE is a computational tool for reconstructing individual haplotypes of intra-host virus strains (a viral quasispecies) without the need for a high quality reference genome. SAVAGE makes use of either FM-index based data structures or ad-hoc consensus reference sequence for constructing overlap graphs from patient sample data. In this overlap graph, nodes represent reads and/or contigs, while edges reflect that two reads/contigs, based on sound statistical considerations, represent identical haplotypic sequence. Following an iterative scheme, a new overlap assembly algorithm that is based on the enumeration of statistically well-calibrated groups of reads/contigs then efficiently reconstructs the individual haplotypes from this overlap graph.

Further methodological details are described in our Genome Research paper.

POLYTE: POLYploid genome fitTEr

POLYTE is a method for reconstructing haplotigs for diploid and polyploid genome, specifically designed for a low-coverage setting where the ploidy of the organism is known. POLYTE follows an iterative scheme where in each iteration reads or contigs are joined, based on their interplay in terms of an underlying haplotype-aware overlap graph. Along the iterations, contigs grow while preserving their haplotype identity. POLYTE has been shown to produce very accurate and complete assemblies, reaching high target genome reconstruction values at extremely low error rates.

Further methodological details are described in our Bioinformatics paper.

VG-Flow

VG-Flow is a computational tool for full-length haplotype reconstruction and abundance estimation from mixed samples. By reformulating the assembly challenge as a flow problem, this algorithm is much more efficient than its predecessor, Virus-VG, allowing also bacterial genomes to be processed. The method is based on the construction of a flow variation graph, capturing all diversity present in the sample. VG-Flow computes a solution to the contig abundance estimation problem and employs a greedy algorithm to efficiently build full-length haplotypes. Finally, VG-Flow calculates accurate frequency estimates for the reconstructed haplotypes through linear programming techniques. Further details are described in our RECOMB paper.

VG-Flow is publicly available under the MIT license at https://bitbucket.org/jbaaijens/vg-flow.

Virus-VG

Virus-VG aims to reconstruct full-length viral haplotypes together with their abundances from the contigs obtained through de novo viral quasispecies assembly (e.g. using SAVAGE). The algorithm makes use of a contig variation graph to capture relationships between pre-assembled contigs, and the final output is represented in the form of a genome variation graph. Further details are described in our Bioinformatics paper.

Virus-VG is publicly available under the MIT license at https://bitbucket.org/jbaaijens/virus-vg.