bioRxiv Science⌕ Search

Biology subjects

Yu, J. A.

Publications and source records attributed to Yu, J. A..

2 recordsLinked to original sources

A fast machine-learning-guided primer design pipeline for selective whole genome amplification

Addressing many of the major outstanding questions in the fields of microbial evolution and pathogenesis will require analyses of populations of microbial genomes. Although population genomic studies provide the analytical resolution to investigate evolutionary and mechanistic processes at fine spatial and temporal scales - precisely the scales at which these processes occur - microbial population genomic research is currently hindered by the practicalities of obtaining sufficient quantities of the relatively pure microbial genomic DNA necessary for next-generation sequencing. Here we present swga2.0, an optimized and parallelized pipeline to design selective whole genome amplification (SWGA) primer sets. Unlike previous methods, swga2.0 incorporates active and machine learning methods to evaluate the amplification efficacy of individual primers and primer sets. Additionally, swga2.0 optimizes primer set search and evaluate strategies, including parallelization at each stage of the pipeline, to dramatically decrease program runtime from weeks to minutes. Here we describe the swga2.0 pipeline, including the empirical data used to identify primer and primer set characteristics, that improve amplification performance. Additionally, we evaluated the novel swga2.0 pipeline by designing primers sets that successfully amplify Prevotella melaninogenica, an important component of the lung microbiome in cystic fibrosis patients, from samples dominated by human DNA.

genomics↗

Worldwide genetic variation of the IGHV and TRBV immune receptor gene families in humans

The immunoglobulin heavy variable (IGHV) and T cell beta variable (TRBV) loci are among the most complex and variable regions in the human genome. Generated through a process of gene duplication/deletion and diversification, these loci can vary extensively between individuals in copy number and contain genes that are highly similar, making their analysis technically challenging. Here, we present a comprehensive study of the functional gene segments in the IGHV and TRBV loci, quantifying their copy number and single nucleotide variation in a globally diverse sample of 109 (IGHV) and 286 (TRBV) humans from over a hundred populations. We find that the IGHV and TRBV gene families exhibit starkly different patterns of variation. In particular, with hundreds of copy number haplotypes (instances that have differences in the number of functional gene segments), the IGHV locus has undergone more frequent gene duplication/deletion compared to the TRBV locus, which has only a few copy number haplotypes. In contrast, the TRBV locus has a greater or at least equal propensity to mutate, as evidenced by greater single nucleotide variation, compared to the IGHV locus. Thus, despite common molecular and functional characteristics, the genes that comprise the IGHV and TRBV loci have evolved in strikingly different ways. As well as providing insight into the different evolutionary paths the IGHV and TRBV loci have taken, our results are also important to the adaptive immune repertoire sequencing community, where the lack of frequencies of common alleles and copy number variants is hampering existing analytical pipelines.

genomics↗