Biology Reference
In-Depth Information
FIGURE 16.6
Although morphologically the boundaries at opposite sides of a cell both shrink, the shared
possession of each boundary between two cells means that only one cell has to shrink each boundary actively, the
adjoining cell simply complying passively.
FIGURE 16.7
The difference between apico-basal polarity, along the z axis of a simple epithelium, and planar
cell polarity that operates at right angles to it, in the x
e
y plane. In the diagram, cells' sense of planar polarity is
depicted by a compass needle and, in the rest of the chapter, compass directions are used to describe this polarity so
that data from a number of different embryos and tissues can be brought together. In published literature, the
'North
e
South' terminology is not used, and directions are instead given according to the anatomical axes in the
tissue in question.
