Figure 5: The nuclear shape remodelling is accompanied by a nuclear volume loss.

(a) Schematic representation of the long axis (a, in red), the short axis (b, in blue), the height (c, in black) and the projected area (dashed green zone) of a nucleus assuming a spheroidal morphology. Quantitative measurements of a, b and c for 1,600 μm² shaped cells (1≥CSI≥0.26) were carried out by laser scanning confocal microscopy. The evolution of a/2 (in red), b/2 (in blue) and c/2 (in black) was plotted as a function of the CSI. Data are given as mean±s.d. with 8≤n≤12. (b) The long-to-short axis ratio (a/b, black curve) and the projected area (green curve), corresponding to the green dashed area in the cartoon presented in a, were plotted as a function of the CSI for SA=1,600 μm². Data are given as mean±s.d. with 8≤n≤12. (c) Superimposed nuclear outlines show clearly the increase in the long-to-short axis ratio, whereas the nuclear projected area decreases. (d) The nucleus was fitted with an ellipsoidal morphology to calculate the evolution of the nuclear volume (in black) and the nuclear surface area (in blue) versus CSI. During cell elongation, both volume and surface area of the nucleus decrease. Data are given as mean±s.d. with 8≤n≤12.