THE SV40 T-ANTIGEN INDUCES PREMATURE APOPTOTIC MAMMARY-GLAND INVOLUTION DURING LATE PREGNANCY IN TRANSGENIC MICE

Transgenic animals of the line 8 contain the WAP-SV-T transgene. Femal es of this line synthesise the SV40 T-antigen in mammary gland epithel ial cells during pregnancy and the lactation period, All females are ' milk-less' and the offspring have to be nursed by foster mothers, The reason for this phenomenon is a premature apoptosis during late pregna ncy, Nonetheless a significant number of mammary epithelial cells esca pe apoptosis and all transgenic females develop breast cancer after th e first lactation period.