Regulation of stem cell function in embryonic mouse mammary progenitor cells. Embryonic mouse mammary progenitor cells

Embryonic mammary stem/progenitors cells, which sit at the lowest rungs of the breast epithelial cell hierarchy, are of considerable interest since they are multipotent precursors to postnatal mammary cells, but embryonic mammary cells are difficult to isolate in sufficient quantities for use in functional experiments. We have established twenty novel cultivable cell lines from embryonic mouse mammary glands in order to facilitate studies of the most primitive breast cells. We have verified these stem/progenitor cell populations by sequencing, marker analysis and phenotypic assays. Differential gene expression profiling reveals that clones isolated from embryonic mammary cells are highly distinct from other stem cell types. Embryonic mammary progenitor cells lack expression of most differentiation markers and can be maintained in an undifferentiated and plastic state.