Berlin 2008 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
BP: Fachverband Biologische Physik
BP 20: Regulation and Signaling
BP 20.1: Invited Talk
Thursday, February 28, 2008, 09:30–10:00, C 243
Modeling noisy concentration gradients inside single cells — Filipe Tostevin1, Pieter ten Wolde2, and •Martin Howard1,3 — 1Dept of Mathematics, Imperial College London, SW7 2AZ, UK — 2AMOLF Institute, Amsterdam, The Netherlands — 3Dept of Systems Biology, John Innes Centre, Norwich NR4 7UH, UK
Many biological systems require precise positional information to function correctly. Examples include positioning of the site of cell division and determination of cell fate during embryonic development. This positional information is often encoded in concentration gradients. A specific protein is produced only within a small region, and subsequently spreads into the surrounding space. This leads to a spatial concentration gradient, with the highest protein concentration near the source. By switching on a signal only where the local concentration is above a certain threshold, this gradient can provide positional information. However, intrinsic randomness in biochemical reactions will lead to unavoidable fluctuations in the concentration profile, which in turn will lead to fluctuations in the identified position. We therefore investigated how precisely a noisy concentration gradient can specify positional information. We found that time-averaging of concentration measurements potentially allows for great precision to be achieved even with remarkably low protein copy numbers. We have applied our results to a number of examples in cell biology, including positioning of the site of cell division in yeast.