Table 1.

Examples of the processes that drive morphogenesis

Change in cell property

Cell migration initiated or stopped

Cell shape change (e.g. columnerisation)

Change in cell density

Adhesion-protein secretion and metalloproteinase secretion (increase cell density)

Adhesion-protein loss and ECM secretion (decrease cell density)

Change in cellular organisation

Epithelial folding (e.g. to form a duct) Duct branching Convergent extension

Cell sorting (e.g. boundary formation through differential expression of cell-surfaceproteins)

Change in differentiation

Mesenchyme → epithelium transition (polarization and lumen formation)

Epithelium → mesenchyme transition polarization (loss of polarization and lumen)

Change in cell number

Proliferation Apoptosis