Pregnancy-associated alterations in DNA methylation patterns of mammary epithelial stem cells [reproductive stages]

Mammary gland development and luminal differentiation occur largely postnatally during puberty and pregnancy. We found that pregnancy had the most significant effects on stem cells, inducing a distinct epigenetic state that remained stable through life. Mammary glands were collected from different reproductive stages to purify different epithelium cell types, which were used for RNA extraction and hybridization on Affymetrix microarrays.