2005 APS March Meeting
Monday–Friday, March 21–25, 2005;
Los Angeles, CA
Session L7: Modeling Large Scale Molecular Biological Data
2:30 PM–5:30 PM,
Tuesday, March 22, 2005
LACC
Room: 408B
Sponsoring
Units:
DBP DCOMP
Chair: Orly Alter, University of Texas at Austin
Abstract ID: BAPS.2005.MAR.L7.5
Abstract: L7.00005 : Population Dynamics of Genetic Regulatory Networks
4:54 PM–5:30 PM
Preview Abstract
Abstract
Author:
Erez Braun
(Department of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel)
Unlike common objects in physics, a biological cell processes
information. The cell interprets its genome and transforms the
genomic
information content, through the action of genetic regulatory
networks,
into proteins which in turn dictate its metabolism, functionality
and
morphology. Understanding the dynamics of a population of biological
cells presents a unique challenge. It requires to link the
intracellular dynamics of gene regulation, through the mechanism of
cell division, to the level of the population. We present
experiments
studying adaptive dynamics of populations of genetically homogeneous
microorganisms (yeast), grown for long durations under steady
conditions. We focus on population dynamics that do not involve
random
genetic mutations. Our experiments follow the long-term dynamics
of the
population distributions and allow to quantify the correlations
among
generations. We focus on three interconnected issues: adaptation of
genetically homogeneous populations following environmental changes,
selection processes on the population and population variability and
expression distributions. We show that while the population exhibits
specific short-term responses to environmental inputs, it eventually
adapts to a robust steady-state, largely independent of external
conditions. Cycles of medium-switch show that the adapted state is
imprinted in the population and that this memory is maintained
for many
generations. To further study population adaptation, we utilize the
process of gene recruitment whereby a gene naturally regulated by a
specific promoter is placed under a different regulatory system.
This
naturally occurring process has been recognized as a major driving
force in evolution. We have recruited an essential gene to a foreign
regulatory network and followed the population long-term dynamics.
Rewiring of the regulatory network allows us to expose their complex
dynamics and phase space structure.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.L7.5