Pnd90
Inguinal mammary gland were sampled from nulliparous female Sprague-Dawley rats mammary glands at stages of pre-pubery (PND21), peri-puberty (PND46), and adulthood (PND90) and snap frozen. Tissues were reduced to powder in liquid nitrogen, and ARN were extracted using the Aurum total RNA fatty and fibrous tissue kit (Bio-Rad, Ontario, Canada, no. 7326830).