Figure 1

Cell populations profiled to define the mammary primordial transcriptome. (A) E12.5 mammary primordium stained with DAPI; the amount of mammary mesenchyme (MM) and dermal mesenchyme (DM) left associated with the mammary bud epithelium (MBE) upon microdissection are indicated. (B) Immunofluorescence with ERα shows stains throughout the mesenchymal tissue that was isolated. Scale bar is 50 μm. (C) Microdissected mammary primordium (MP). (D) Mammary bud epithelium after tissue separation. (E) Mammary primordial mesenchyme after tissue separation. (F) Heatmap and supervised clustering of differential gene expression across mammary primordial tissues with probe sets with the most tissue-specific expression. Each horizontal line represents a probe set with red indicating high and green indicating low expression.