DIFFERENTIAL EXPRESSION OF THE NEU TRANSGENE IN MURINE MAMMARY TISSUES

The mammary glands of control FVB and mice with MTV-LTR promoted trans genes were stained using immunohistochemistry to detect neu expression . Neu expression in the terminal end buds of developing mammary glands and during early pregnancy in FVB mice was confirmed by in situ hybri dization. Neu was expressed in all tumors from mice with the neu trans gene but not in tumors expressing transforming growth factor alpha (TG F alpha) or polyoma virus middle T (PyV-MT). Neu was also expressed sp oradically in non-neoplastic mammary cells of transgenic neu mice. How ever, most mammary cells expressing neu were dysplastic. The different ial expression of the neu transgene has important implications for the interpretation of transgenic biology.