Abstract | A major unanswered question in cell biology is how cells regulate the size of organelles. We are using the eukaryotic flagellum as a simple system to probe the nature of organelle size control. By analysis of flagellar growth dynamics, we have developed a simple model for length control based on the interplay between length-independent turnover of flagellar microtubules and length-dependent transport of fresh protein to the turnover site. Our model can recapitulate the main phenomenological features of flagellar length including the ability of the cell to equalize the lengths of its flagella following perturbations. We are now probing the fluctuations in the length control system, combining experimental measurements with a linear noise analysis. Finally, we have begun to integrate an additional transcription-based feedback control loop into the model. |