Regenerated glands produced <i>in vivo</i> from MRU generated <i>in vitro</i> from structures generated from single fetal, basal, or luminal cells.

<p>Whole mounts (upper panels) and sections (middle panels) of mammary glands produced in fat pads injected with cells from cultures initiated with single fetal cells (left panel), or single adult basal cells (middle panel) or single adult luminal cells (right panels). Scale bars, 100 µm (whole mounts) and 50 µm (sections). Lower panels show flow cytometry profiles of regenerated mammary glands from cultures initiated with single fetal cells (left panel), or single adult basal (middle panel) or six CD61⁺ luminal cells (right panels).