Eigen-genomic system dynamic-pattern analysis (ESDA): modeling mRNA degradation and self-regulation

IEEE/ACM Trans Comput Biol Bioinform. 2012;9(2):430-7. doi: 10.1109/TCBB.2011.150. Epub 2011 Nov 11.

Abstract

High-throughput methods systematically measure the internal state of the entire cell, but powerful computational tools are needed to infer dynamics from their raw data. Therefore, we have developed a new computational method, Eigen-genomic System Dynamic-pattern Analysis (ESDA), which uses systems theory to infer dynamic parameters from a time series of gene expression measurements. As many genes are measured at a modest number of time points, estimation of the system matrix is underdetermined and traditional approaches for estimating dynamic parameters are ineffective; thus, ESDA uses the principle of dimensionality reduction to overcome the data imbalance. Since degradation rates are naturally confounded by self-regulation, our model estimates an effective degradation rate that is the difference between self-regulation and degradation. We demonstrate that ESDA is able to recover effective degradation rates with reasonable accuracy in simulation. We also apply ESDA to a budding yeast dataset, and find that effective degradation rates are normally slower than experimentally measured degradation rates. Our results suggest that either self-regulation is widespread in budding yeast and that self-promotion dominates self-inhibition, or that self-regulation may be rare and that experimental methods for measuring degradation rates based on transcription arrest may severely overestimate true degradation rates in healthy cells.

MeSH terms

  • Algorithms
  • Cell Cycle / genetics
  • Computational Biology / methods*
  • Computer Simulation
  • Gene Expression Regulation
  • Genome
  • Models, Genetic*
  • RNA Stability / genetics*
  • Saccharomycetales / genetics
  • Saccharomycetales / metabolism