title: A Bayesian approach to reconstructing genetic regulatory networks with hidden factors.
abstract: BACKGROUND
  We have used state-space models (SSMs) to reverse engineer transcriptional networks from highly replicated gene expression profiling time series data obtained from a well-established model of T cell activation. SSMs are a class of dynamic Bayesian networks in which the observed measurements depend on some hidden state variables that evolve according to Markovian dynamics. These hidden variables can capture effects that cannot be directly measured in a gene expression profiling experiment, for example: genes that have not been included in the microarray, levels of regulatory proteins, the effects of mRNA and protein degradation, etc.
  
  
  RESULTS
  We have approached the problem of inferring the model structure of these state-space models using both classical and Bayesian methods. In our previous work, a bootstrap procedure was used to derive classical confidence intervals for parameters representing 'gene-gene' interactions over time. In this article, variational approximations are used to perform the analogous model selection task in the Bayesian context. Certain interactions are present in both the classical and the Bayesian analyses of these regulatory networks. The resulting models place JunB and JunD at the centre of the mechanisms that control apoptosis and proliferation. These mechanisms are key for clonal expansion and for controlling the long term behavior (e.g. programmed cell death) of these cells.
  
  
  BACKGROUND
  Supplementary data is available at http://public.kgi.edu/wild/index.htm and Matlab source code for variational Bayesian learning of SSMs is available at http://www.cse.ebuffalo.edu/faculty/mbeal/software.html.
authors.affiliation: Department of Computer Science & Engineering, State University of New York at Buffalo, 201 Bell Hall, Buffalo, NY 14260-2000, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Beal
authors.forename: Francesco
authors.initials: F
authors.lastname: Falciani
authors.forename: Zoubin
authors.initials: Z
authors.lastname: Ghahramani
authors.forename: Claudia
authors.initials: C
authors.lastname: Rangel
authors.forename: David L
authors.initials: DL
authors.lastname: Wild
mesh_terms: D001499:Bayes Theorem; D003198:Computer Simulation; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation / Q000502:physiology*; D008390:Markov Chains; D008957:Models, Genetic; D015233:Models, Statistical; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D014157:Transcription Factors