Friday, Dec. 10

Tomas Gedeon
Department of Mathematical Sciences
Montana State University


Title:  Modeling nitrogen catabolite repression gene regulatory circuit in
yeast.

 We develop a  model of   a gene regulatory circuit involved in nitrogen
catabolite repression (NCR)
in yeast. The model consists of a large system of  periodically forced
delay-differential equations, where delay accounts for transcriptional and
translational delays and the periodical  forcing describes cell cycle.

 We analyze two subcircuits of the full circuit, GLN3-URE2 subcircuit,
and GLN3-URE2-GAT1
 subcircuit. The role of the first is to switch the circuit on  and
off. Using various tools, most
 prominently the monotone system theory, we conclude that the behavior of
these subcircuits is
 generically simple: almost all solutions converge to a periodic orbit,
whose period is a multiple  of the cell cycle length.