Fig. 1. Relative expression of potential interacting genes in 5-week-old mammary glands. Cy5-labeled cDNAs from microdissected TEB- or duct-containing regions and Cy3-labeled cDNAs from distal stroma were hybridized to long-oligonucleotide microarrays. TEB/stroma (Cy5/Cy3) expression ratios and duct/stroma ratios are each shown for six independent experiments (lanes 1-6) and their respective means (M) using the color scale shown, with black indicating no difference in expression, red indicating relative enrichment within the TEB or duct regions and green representing relative enrichment in the pure distal stroma. Thus, intense red indicates a greater than fourfold enrichment in and around TEBs or ducts. Relative expression levels for ADAM10 are shown for two independent oligonucleotides, whereas all other genes were represented by a single oligonucleotide. Genes for which the mean overall fluorescence signal A=0.5[log₂(Cy5) + log₂(Cy3)] was consistently more than eight, the level below which it was difficult distinguish true signal from noise.