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Gavriliuc, S.

Publications and source records attributed to Gavriliuc, S..

2 recordsLinked to original sources

De novo reconstruction of microbial haplotypes by integrating statistical and physical linkage

DNA sequencing technologies provide unprecedented opportunities to analyze within-host evolution of microorganism populations. Often, within-host populations are analyzed via pooled sequencing of the population, which contains multiple individuals or haplotypes. However, current next-generation sequencing instruments, in conjunction with single-molecule barcoded linked-reads, cannot distinguish long haplotypes directly. Computational reconstruction of haplotypes from pooled sequencing has been attempted in virology, bacterial genomics, metagenomics and human genetics, using algorithms based on either cross-host genetic sharing or within-host genomic reads. Here we describe PoolHapX, a flexible computational approach that integrates information from both genetic sharing and genomic sequencing. We demonstrated that PoolHapX outperforms state-of-the-art tools tailored to specific organismal systems, and is robust to within-host evolution. Importantly, together with barcoded linked-reads, PoolHapX can infer whole-chromosome-scale haplotypes from 50 pools each containing 12 different haplotypes. By analyzing real data, we uncovered dynamic variations in the evolutionary processes of within-patient HIV populations previously unobserved in single position-based analysis.

bioinformatics↗

A database for ITS2 sequences from nematodes

Marker gene surveys have a wide variety of applications in species identification, population genetics, and molecular epidemiology. As these methods expand to new types of organisms and additional markers beyond 16S and 18S rRNA genes, comprehensive databases are a critical requirement for proper analysis of these data. Here we present an ITS2 rDNA database for maker gene surveys of both free-living and parasitic nematode populations and the software used to build the database. This is an important resource for researchers working on nematodes and also provides a tool to create ITS2 databases for any given taxonomy.\n\nAvailability and ImplementationThe database is available as an interactive web app at https://cooperia.chgi.ucalgary.ca/Nematode_ITS2/. The full database can also be downloaded from zenodo https://doi.org/10.5281/zenodo.3235802, and the open source software used to create the database, markerDB is available at https://github.com/ucvm/markerDB/releases/latest.

bioinformatics↗