Fig. 1.

Menin overexpression induces βHC9 cells to become compact and clustered. Two types of βHC9-derived cell lines are shown: mock (pMX-puro empty vector) and Men1-TAP (overexpressing menin-TAP). Differential interference contrast images of cells are shown at low (A, B) and high (C, D) magnification. Texas Red-phalloidin staining was used to assess the organization of F-actin. Eleven confocal Z-stacks were taken and projected into one image (E, F), and a single confocal section stained for F-actin and for nuclei with DAPI is also shown (G-H). The morphological polarity of a cell was defined by a seminquantitative index of cell shape as described by Donnadieu and coworkers (Donnadieu et al., 1992). Briefly, the cell was traced as an ellipse using Photoshop software. Two lines were drawn: one along the longest axis of the ellipse; the other perpendicular to the first and bisecting it. The cell shape index was determined by the ratio of the long axis to the short axis.