(A) Score-plot of PCA scores for all cells from the main dataset, with cells colored by the developmental stage of the animal: from reds for stages 43–44, through yellows for stages 45–46, to blues for stages 48–49. Note that most red cells are located on the left, while most light blue cells (stage 47) are located on the right. (B) Isolated sub-clouds of points from panel (A), shown on the same axes as panel (A), and illustrating the progression of different stages through the score-plot (N points = 11, 64, 24, and 56). Estimated density kernels for sub-clouds are shown as colored backgrounds. Stages 43–47 illustrate that the cloud moved to the right, while at stages 48–49 it moved back to the center, and expanded at all directions (see quantification in the text).