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Biology subjects

Brier, T.

Publications and source records attributed to Brier, T..

3 recordsLinked to original sources

COTree: A Statistical Framework for Deciphering Cell-Resolved Multi-Omics Trajectories

Recent advances in whole-cell modeling enable the computational tracking of the temporal evolution of thousands of molecular species across genomic, transcriptomic, proteomic, and metabolomic layers. These models provide a complementary perspective for studying cellular dynamics, offering continuous, system-wide observations that are difficult to obtain from experimental technologies, which are often destructive and yield only static measurements from limited modalities. While whole-cell models generate multi-omic simulation trajectories with high temporal resolution, analyzing and interpreting such complex data remains a major challenge that limits their potential to elucidate cellular dynamics. To address this challenge, we propose COTree, a statistical framework that learns integrated multi-omic representations and constructs a trajectory principal tree to summarize cellular progression patterns. COTree enables a broad range of downstream analyses, including cell classification, fate prediction, developmental time detection, and driver species identification, that provide new insights into how cells develop and differentiate. To demonstrate its practical utility, we apply COTree to a multi-omic trajectory dataset generated from the whole-cell model of JCVI-Syn3A, revealing cell types, characterizing long-term cellular dynamics, and identifying key driver species associated with cell death and replication.

bioinformatics↗

Generation of virtual populations for quantitative systems pharmacology through advanced sampling methods

Virtual population (VPop) generation is a central component of quantitative systems pharmacology (QSP), involving the sampling of parameter sets that represent physiologically plausible patients and capture observed inter-individual variability in clinical outcomes. This approach poses challenges due to the high dimensionality and often non-identifiability nature of many QSP models. In this study, we evaluate the performance of the DREAM(ZS) algorithm, a multi-chain adaptive Markov chain Monte Carlo (MCMC) method for generating VPop. Using the Van De Pas model of cholesterol metabolism as a case study, we compare DREAM(ZS) to the single-chain Metropolis-Hastings (MH) algorithm introduced by Rieger et al. Our comparison focuses on convergence behavior, parametric diversity, and posterior coverage, in relation to the ability of each method to explore complex parameter distributions and maintain correlations. DREAM(ZS) demonstrates superior exploration of the parameter space, reducing boundary accumulation effects common in traditional MH sampling, and restoring parameter correlation structures. These advantages are attributed in part to its adaptive proposal mechanism and the use of a bias-corrected likelihood formulation, which together contribute to a better parameters space sampling without compromising model fit. Our findings contribute to the ongoing development of efficient sampling methodologies for high-dimensional biological models, introducing a promising and easy to use alternative for VPop generation in QSP, expanding the methodological approaches for in silico trial simulation.

systems biology↗

PrimalScheme: open-source community resources for low-cost viral genome sequencing

Viral genome sequencing using the ARTIC protocol has been a vital tool for understanding the spread of epidemics including Ebola, Zika, Covid-19 and Mpox and has seen widespread adoption due to its low cost and high sensitivity. Here, we describe PrimalScheme, an open-source toolkit and website that allows users to easily design primer schemes for amplicon sequencing of viruses, and has generated over 67,000 primer schemes for the global community since 2017. In January 2020, PrimalScheme was used to rapidly generate a primer scheme for SARS-CoV-2, with primer pools distributed to researchers from 44 countries to help scale-up genomic surveillance efforts. Overall, these primers were used to generate an estimated 18M genome sequences and the protocols were viewed online [~]250K times. To complement PrimalScheme, we have built PrimalScheme Labs, a scheme repository which allows users to find and share primer schemes as well as establishing a set of data standards. Through improvements to the primer design process, including the use of discrete primer clouds, we have expanded the use of amplicon sequencing to include diverse virus species. We demonstrate the utility of this approach through a high diversity pan-genotype Measles virus (MeV) scheme. We also demonstrate its use on a high sensitivity, short amplicon Monkeypox virus (MPXV) scheme with over 1000 primers, showing high genome recovery on low-titre clinical samples. These developments have implications for sequencing from samples such as wastewater, for genomic surveillance of endemic pathogens and in preparing for future pandemics.

genomics↗