Although in culture epithelial cells are prone to forming connections with neighboring cells and traveling in colonies, one small LLC-MK2 cell succeeds in obtaining independence from a large group of cells. The cell’s autonomy is short-lived, however, as it seems to be almost irresistibly drawn back to its former place in the colony. The directed movements of the cell are coordinated through the extension and contraction of broad, flattened lamellipodia. Notice, later in the video the cell appears to be pushed across the field of view by a section of the colony that begins actively migrating toward the left.

The LLC-MK 2 cells in this video repeatedly undergo cell division. Groups of the epithelial cells migrate together to fill in all of the available space in the imaging chamber. Though only about half of the field of view abounds with cells at the beginning of the time-lapse sequence, by the end an almost continuous monolayer has been formed.

Vacuole formation is pronounced in many of the rhesus monkey kidney cells. The membrane-bound sacs are formed along the peripheries of the cells via endocytosis. The endocytic process entails an invagination and pinching off of the plasma membrane to internalize extracellular substances. In culture, the material most commonly contained in vacuoles is culture medium, which the cells digest to obtain nutrients.