Bayesian localization of CNV candidates in WGS data within minutes
Journal article, 2019

Background: Full Bayesian inference for detecting copy number variants (CNV) from whole-genome sequencing (WGS) data is still largely infeasible due to computational demands. A recently introduced approach to perform Forward-Backward Gibbs sampling using dynamic Haar wavelet compression has alleviated issues of convergence and, to some extent, speed. Yet, the problem remains challenging in practice.

Results: In this paper, we propose an improved algorithmic framework for this approach. We provide new space-efficient data structures to query sufficient statistics in logarithmic time, based on a linear-Time, in-place transform of the data, which also improves on the compression ratio. We also propose a new approach to efficiently store and update marginal state counts obtained from the Gibbs sampler.

Conclusions: Using this approach, we discover several CNV candidates in two rat populations divergently selected for tame and aggressive behavior, consistent with earlier results concerning the domestication syndrome as well as experimental observations. Computationally, we observe a 29.5-fold decrease in memory, an average 5.8-fold speedup, as well as a 191-fold decrease in minor page faults. We also observe that metrics varied greatly in the old implementation, but not the new one. We conjecture that this is due to the better compression scheme. The fully Bayesian segmentation of the entire WGS data set required 3.5 min and 1.24 GB of memory, and can hence be performed on a commodity laptop.

HMM

CNV

Wavelet

Bayesian inference

Author

John Wiedenhoeft

Chalmers, Computer Science and Engineering (Chalmers), Data Science

Rutgers University

Alex Cagan

Wellcome Trust Sanger Institute

Max Planck Society

Rimma Kozhemyakina

Russian Academy of Sciences

Rimma Gulevich

Russian Academy of Sciences

Alexander Schliep

Rutgers University

University of Gothenburg

Algorithms for Molecular Biology

17487188 (eISSN)

Vol. 14 1 20

Subject Categories

Bioinformatics (Computational Biology)

Probability Theory and Statistics

Computer Vision and Robotics (Autonomous Systems)

DOI

10.1186/s13015-019-0154-7

More information

Latest update

7/18/2023