Gene expression in postnatal mammary gland development -pregnancy day 14 and lactation day 2

Previoulsly expression profiling of the whole mammary gland across different stages of pregnancy and lactation has been performed on different strains of mice. Since mammary gland has both epithelial and stromal compartments, to specifically identify the genes involved in the transition from pregnancy to lactation a process termed as secretory activation, expression profiling of isolated mammary epithelial cells (MECs) from four CD1 mice each at Pregnancy day 14 (P14) and Lactation day 2 (L2) was performed in the current study. Statistical analysis of the mRNA changes between P14 and L2 identified 5,499 unique genes as being differentially expressed (5% FDR), of which, 2,902 genes and 2,604 genes were higher in P14 or L2 stages, respectively. 4 replicates each from Pregnancy day 14 and Lactation day 2 were hybridized onto Affymetrix GeneChip® Mouse Gene 1.0 ST Array (28,853 genes)