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BP: Fachverband Biologische Physik
BP 30: Posters: Physics of Cells
BP 30.31: Poster
Donnerstag, 17. März 2011, 17:15–20:00, P3
Dynamics of P-granule formation and localization in C.elegans embryos — •Jöbin Gharakhani1, Chiu Fan Lee1, Clifford P. Brangwynne1, 2, Anthony A. Hyman2, and Frank Jülicher1 — 1Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 2Max Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
During embryonic development, precursor germ cells contain aggregates of proteins and RNA known as germ granules (``P-granules''), which are important in the specification of a functioning germ line. In the first cell division of the fertilized egg of the worm, C.elegans, P-granules segregate towards the posterior side of the cell; upon cell division, they are found only in the posterior daughter cell. This segregation occurs through preferential growth of the P-granules on the posterior side of the cell. This preferential growth is maintained by a gradient in the concentration of the protein MEX-5 along the anterior-posterior axis of the cell. MEX-5 appears to decrease the saturation point for a phase transition into the condensed granule phase along this axis, thereby allowing a spatially asymmetric nucleation and growth. We use a simulation based on the Lifshitz-Slyozov model for droplet growth to study this system, where the model is expanded to include a spatial supersaturation gradient. We find that P-granules preferentially stay at the posterior side due to two effects: i) the lower saturation point allows for greater P-granule growth, and ii) larger P-granules diffuse more slowly.