Transcription and mRNA splicing of the human lactoferrin gene controlled by the regulatory region of the bovine αS1 casein gene in the mammary gland of transgenic mice and in mouse embryonic stem cells

The regulatory region of the bovine alpha S1 casein gene was used to obtain two genetic constructs for expression of human lactoferrin in the mammary gland of transgenic animals. Several transfected mouse embryonic stem cell (ESC) lines and primary transgenic mice were generated with these constructs. Recombinant lactoferrin was not detected in milk of transgenic mice by Western blotting. However, a recombinant transcript, was found in RNAs isolated from mammary glands of transgenic females during lactation and from transfected ESC lines.