[UCLAStat] Seminar:November 6, "Two Problems in Genomics"

[Sabatti, Chiara]

  UCLA DEPARTMENT OF STATISTICS 
  DEPARTMENT SEMINAR 

  3:00 p.m., Tuesday, November 6, 2001 
  Mathematical Sciences Building Room 6627 
  (Cookies at 2:45 in the Graduate Student Lounge 8118) 

  Kerby A Shedden 
  Department of Statistics 
  University of Michigan 

  Two Problems in Genomics that can be Addressed by Statistical Modeling and
Simulation 
 
   ABSTRACT 


I will discuss two difficult and important problems that arise in genomics.
Both problems are addressed by incorporating specific biological information
into a statistical model that accounts for uncertainty regarding the
biological laws and uncertainty arising from measurement and sampling
variation. The resulting models are complex, and various simulation tools
are used to fit the models to data. Brief descriptions of the two problems
follow. 

1. Separation of Expression Signals from Mixed Cell Populations. When
measuring gene expression in cells taken from tissue, it is nearly certain
that several cell types will be present in addition to the cell type of
interest. I will discuss a procedure for estimating the expression signals
corresponding to the biologically-pure sub-populations of cells that
comprise the sample. 

2. Identification of Global Regulators of Gene Expression. The
loosely-defined term "global regulator" refers to a relatively small number
of genes whose products have a wide-ranging influence on the state of the
cell. One mechanism of action of these regulators is that their products
bind the DNA slightly upstream of the coding region of the gene whose
expression they influence. Thus there is information in both gene expression
and genome sequence measurements regarding the identities of the global
regulators. I will discuss a graph-structured probability model for
identifying global regulators.