microRNA expression in postnatal mammary gland development -Pregnancy Day14 and Lactation day 2. Mus musculus

Previoulsly miRNA expression profiling of the whole mammary gland across different stages of pregnancy and lactation has been performed in mice. Since mammary gland has both epithelial and stromal compartments, to specifically identify the miRNAs 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 miRNA changes between P14 and L2 identified 32 miRNAs to be differentially expressed with a fold change greater than or equal to 2, of which, the majority of them declinied at the onset of lactation. Overall design: 4 replicates each from Pregnancy day 14 and Lactation day 2 were hybridized onto Affymetrix GeneChip® miRNA 1.0 ST Array (7,625 probesets)