how do cell and nuclear shape changes influence the nucleolus ?

Ribosomes are molecular machineries responsible for translation, which is the cellular process converting genetic information into proteins. Considering the importance of ribosomes to all living forms makes understanding its assembly a crucial event. Despite growing evidences about the close relationship between ribosome biogenesis and the cell cycle regulation, how the mechanical stress affects the ribosome biogenesis is still unclear. Here we investigate this open question by studying the effect of cellular geometry on the nucleolus, which is the hosting hub of ribosome biogenesis. By using fibronectin-coated micropatterns of defined shapes and areas, we imposed the spreading geometry of individual endothelial cells. We found that average nucleolar area in the nucleus increases with the increase in nuclear area. We also revealed that the nuclear deformation leads to an increase of the nucleoli number per cell. Our preliminary results suggest that cell elongation modulates the ribosome biogenesis through the nuclear shape remodelling. Based on these results, we will then study the influence of the cellular and nuclear deformations on the expression of different ribosome biogenesis related genes and the associated signalling pathways.