Here is a great photo from Nature Reviews Molecular Biology.  I was looking at the intermediate filaments (red) and understanding the effect of looking through 3D space, with fewer filaments on either side of the central area where the nucleus resides.  There is no equivalent effect seen with the desmosomes… they only occur at the widest part of the cell….So tell me… what sense (other than the tension and arrangement of the intermediate filaments (which also are pointedly connected to the nuclear pores) do they “feel” that tells them the widest part of the cell.  In stratified epithelia, there are many belts… .but this is tissue culture… only one belt.

Without question, cells in culture can sense “confluence”, but this is still a single layer, and the belt is the equator (but the shape is not spherical (haha).  Awesome. Some have suggested that confluence is required for mature desomosomal appearance.