Supplemental Material

This article contains the following supporting material:

• Video1 - AT II cells form cell density-dependent ALC. AT II cells were grown in Matrigel culture for six days starting at a cell density of 5 x 10⁴ (left panel) or 25 x 10⁴ (right panel) cells/cm². Images were collected at 15 min intervals beginning eight hours after plating. Image size: 480 x 1280 μm.
• Video2 - The function-inhibiting antibody AIIB2 blocks β1-integrin and inhibits cell aggregation. AT II cells were cultured in Matrigel for three days in the presence (left panel) or absence (right panel) of AIIB2. AIIB2 was added five hours after plating. AIIB2 did not affect cell movement: cells collided frequently with neighbors but failed to adhere. Images were recorded at 15 min intervals beginning three hours after AIIB2 treatment. Image size: 480 x 1280 μm.
• Video3 - MDCK cells from cysts in matrigel. MDCK cells were cultured in 2% matrigel for up to 8 days. Left panel shows one MDCK cell proliferate to form a clonal cysts, and right panel shows multiple cells form one cysts by cell proliferation and aggregation. Image size: 119 x 238 μm.
• Video4 - Forskolin treatment expands ALC. After three days of culture, forskolin was added to cells in the left panel. Thereafter, over the next 24 hours, the ALC expanded dramatically. The right panel shows control cells. Image size: 480 x 1280 μm.