Figure 2
Validation and network analysis of mammary primordial epithelium microarray data. (A) Krt5, Krt14, Krt8, Krt18, Itga6/CD49f, and Epcam are expressed by many mammary primordial epithelial cells at high levels while some cells do not stain or express lower levels of these markers. All mammary primordial epithelial cells express p63. Laminin stains along the epidermal-mesenchymal boundary. Ctnnb1/β-catenin and Itgb4 are expressed at varying levels by cells within the primordia. Trim29 is expressed predominantly by basal cells. Scale bar is 50 μm. (B) qRT-PCR analysis of RNA from enzymatically separated E12.5 mammary bud epithelium (MBE) and mammary mesenchyme (MM). Gene RNA levels are expressed relative to Actb levels. Error bars ± s.e.m. Validation of eight mammary bud epithelium (MBE) specific genes showing enriched expression when compared to the mammary mesenchyme (MM). (C) A kinase-activin receptor sub-module is detected by network analysis. This sub-module forms part of the core network module generated using human orthologues of physically interacting genes characteristic of E12.5 mammary primordial epithelium. Black lines represent protein-protein interactions.