Wnt3a leads to increased cell-cell interactions.

<p>Representative fluorescent photomicrographs (left) and corresponding CellProfiler Image analysis (right) of B6GFP cluster cells following control or Wnt3a treatment after 1 day (<b>A</b>) and 4 days (<b>B</b>). The color gradient labels individual cells according to the number of directly-contacted neighboring cells. (<b>C, D</b>) Percentage of clustering cells after 1 day (solid line) and 4 days (dashed line) following control (C) and Wnt3a treatment (D). Wnt3a stimulates cells to cluster, while most cells remain as singles or doublets in controls. (<b>E</b>) Cluster-formation assay results showing SSC numbers over the course of feeder-free culture with or without Wnt3a. Increased SSC maintenance is observed with Wnt3a.