Morphogenesis by Orientated Cell Division - Mechanisms of Morphogenesis - page 294

FIGURE 23.8 Possible means by which the positions of adherens junctions control the orientation of the mitotic
spindle in epithelial cells, to ensure that daughters each retain contact with the basement membrane. Clearly, it must
be possible for this system to be overridden when division in the other direction is required (as, for example, in the
endometrium example).
stem cell character due to short-range signals coming from the hub, while the other cell
becomes a gonioblast which undergoes further rounds of mitosis and then enters meiosis.
If APC function is disrupted, mitotic orientation of the stem cell becomes randomized. 25
It is interesting to note, in passing, that the protein APC acquired its name from the human
disease adenomatous polyposis coli, which is associated with heterozygous APC mutation.
FIGURE 23.9 Schematic of stem cell mitosis in the testis of D. melanogaster, showing the disorientating effects of
loss of APC function.