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Biology subjects

Williams, E. C.

Publications and source records attributed to Williams, E. C..

2 recordsLinked to original sources

noisyR: Enhancing biological signal in sequencing datasets by characterising random technical noise

High-throughput sequencing enables an unprecedented resolution in transcript quantification, at the cost of magnifying the impact of technical noise. The consistent reduction of random background noise to capture functionally meaningful biological signals is still challenging. Intrinsic sequencing variability introducing low-level expression variations can obscure patterns in downstream analyses. We introduce noisyR, a comprehensive noise filter to assess the variation in signal distribution and achieve an optimal information-consistency across replicates and samples; this selection also facilitates meaningful pattern recognition outside the background-noise range. noisyR is applicable to count matrices and sequencing data; it outputs sample-specific signal/noise thresholds and filtered expression matrices. We exemplify the effects of minimising technical noise on several datasets, across various sequencing assays: coding, non-coding RNAs and interactions, at bulk and single-cell level. An immediate consequence of filtering out noise is the convergence of predictions (differential-expression calls, enrichment analyses and inference of gene regulatory networks) across different approaches. TeaserNoise removal from sequencing quantification improves the convergence of downstream tools and robustness of conclusions.

bioinformatics

feamiR: Feature selection based on Genetic Algorithms for predicting miRNA-mRNA interactions

microRNAs play a key role in RNA interference, the sequence-driven targeting of mRNAs that regulates their translation to proteins, through translation inhibition or the degradation of the mRNA. Around ~ 30% of animal genes may be tuned by microRNAs. The prediction of miRNA/mRNA interactions is hindered by the short length of the interaction (seed) region (~7- 8nt). We collate several large datasets overviewing validated interactions and propose feamiR, a novel pipeline comprising optimised classification approaches (Decision Trees/Random Forests and an efficient feature selection based on embryonic Genetic Algorithms used in conjunction with Support Vector Machines) aimed at identifying discriminative nucleotide features, on the seed, compensatory and flanking regions, that increase the prediction accuracy for interactions. Common and specific combinations of features illustrate differences between reference organisms, validation techniques or tissue/cell localisation. feamiR revealed new key positions that drive the miRNA/mRNA interactions, leading to novel questions on the mode-of-action of miRNAs.

bioinformatics