Additional file 5: Figure S5. of Evidence of two distinct functionally specialized fibroblast lineages in breast stroma

Branching morphogenesis reflects activity of luminal progenitors. Primary cultures of purified luminal breast epithelial cells plated at clonal density on confluent feeders of (left column) CD26high or (right column) CD105high fibroblasts stained for MUC1 by immunoperoxidase. Nuclear counterstain is omitted to clearly outline epithelial cells. EpCAMhigh/CD166high/67LRhigh differentiated luminal epithelial cells (CD166high/67LRhigh) remained as single cells upon confrontation with fibroblast feeders (upper panel), while EpCAMhigh/CD166low/67LRlow progenitors (CD166low/67LRlow) responded by undergoing branching morphogenesis with larger structures forming on CD105high fibroblasts (lower panel) (scale bar = 100 μm). (PDF 9484 kb)