In-vivo induction of lactation in mammary glands isografted from neonates to pregnant mice

Abstract

Neonatal mammary rudiments isografted into C3H mice at mid-pregnancy responded to endogenous gestational and puerperal hormonal stimuli in the hosts with morphogenetic and functional differentiation, and lactated within 9 days after birth. Neither lobuloalveolar development nor lactation took place in neonatal mammary isografts when intrauterine fetal death or stillbirth occurred in the pregnant host mice or when neonatal mammary rudiments were isografted into puerperal mice without being exposed to gestational hormonal stimuli before transplantation. Neonatal mammary rudiments isografted on day 0 post partum had much more extensive proliferation of end-buds when recovered on day 12 than on day 21 post partum. Histological features of neonatal mammary grafts closely reflected the endogenous hormonal condition of the host mice.