Figure 2. In silico reconstitution of... | Rockefeller University Press

Figure 2.

$Figure 2. In silico reconstitution of keratinocyte stem cell colony dynamics. (A) Distribution of locomotion speed of keratinocytes in a progressively growing colony after 6 d of cultivation. Each color indicates different locomotion speeds that were calculated with 3-h time-lapse observation. (B) Locomotion speed of cells located at the inner and outer portion of progressively growing colonies. Each dot represents the speed of each keratinocyte in the colony. Dots arranged vertically indicate the speed of cells in the same colony. Mean speed of each cell fraction is shown with red bars. Locomotion speed was calculated with 30-min time-lapse observation. 51 outer cells and 35 inner cells in seven progressive growing colonies were analyzed. P-values were calculated by Student’s t test. (C) Two-dimensional modeling of interaction of rotating keratinocytes. Cells were provided with 24 µm (=l0) of a planar diameter and can rotate around the contacting cells at 0.5 π/h (=ω0). The rotational speed of cell j against cell i, ωj-i, was defined as ωj-i = ω0exp(−(lj-i − l0)/d). lj-i is the distance between the centers of cell i and cell j, and d = l0/2 is a constant. i, j = 1, 2, 3, … , 100 and i ≠ j. The input parameters used are described in the Results section. (D) Distribution of locomotion speed of keratinocytes in a progressively growing colony in silico. The speed of each cell was calculated by a simulation experiment based on our modeling (See Materials and methods). (left) All cells constituting the colony rotate clockwise. (right) 20% of cells in the colony rotate CCW. Each color indicates different locomotion speeds. The data shown were obtained from a single representative experiment using a random number generator with three random seeds (triplicate experiments). (E, left) The colony containing 20% of CCW cells showed the highest mean speed of locomotion even if all cells had the same rotational speed (0.5 π/h). (middle) Rotation speed of cells determined cell locomotion speed in the colony. The percentage of CCW rotating cells was fixed at 20%. (right) Variation of locomotion speed of cells was reproduced with a mixture of fast (0.5 π/h) and slow (0.2 π/h) rotating cells. The percentage of CCW rotating cells was fixed at 20%. The data shown were obtained from a single representative experiment using a random number generator with three random seeds (triplicate experiments). (F) Schematic representation of cell locomotion speed in each clonal type. The simulation predicted that a holoclone colony could be identified by measuring cell locomotion speed.$

In silico reconstitution of keratinocyte stem cell colony dynamics. (A) Distribution of locomotion speed of keratinocytes in a progressively growing colony after 6 d of cultivation. Each color indicates different locomotion speeds that were calculated with 3-h time-lapse observation. (B) Locomotion speed of cells located at the inner and outer portion of progressively growing colonies. Each dot represents the speed of each keratinocyte in the colony. Dots arranged vertically indicate the speed of cells in the same colony. Mean speed of each cell fraction is shown with red bars. Locomotion speed was calculated with 30-min time-lapse observation. 51 outer cells and 35 inner cells in seven progressive growing colonies were analyzed. P-values were calculated by Student’s t test. (C) Two-dimensional modeling of interaction of rotating keratinocytes. Cells were provided with 24 µm (=l₀) of a planar diameter and can rotate around the contacting cells at 0.5 π/h (=ω₀). The rotational speed of cell j against cell i, ω_j-i, was defined as ω_j-i = ω₀exp(−(l_j-i − l₀)/d). l_j-i is the distance between the centers of cell i and cell j, and d = l₀/2 is a constant. i, j = 1, 2, 3, … , 100 and i ≠ j. The input parameters used are described in the Results section. (D) Distribution of locomotion speed of keratinocytes in a progressively growing colony in silico. The speed of each cell was calculated by a simulation experiment based on our modeling (See Materials and methods). (left) All cells constituting the colony rotate clockwise. (right) 20% of cells in the colony rotate CCW. Each color indicates different locomotion speeds. The data shown were obtained from a single representative experiment using a random number generator with three random seeds (triplicate experiments). (E, left) The colony containing 20% of CCW cells showed the highest mean speed of locomotion even if all cells had the same rotational speed (0.5 π/h). (middle) Rotation speed of cells determined cell locomotion speed in the colony. The percentage of CCW rotating cells was fixed at 20%. (right) Variation of locomotion speed of cells was reproduced with a mixture of fast (0.5 π/h) and slow (0.2 π/h) rotating cells. The percentage of CCW rotating cells was fixed at 20%. The data shown were obtained from a single representative experiment using a random number generator with three random seeds (triplicate experiments). (F) Schematic representation of cell locomotion speed in each clonal type. The simulation predicted that a holoclone colony could be identified by measuring cell locomotion speed.