Abstract: A nuclear scaffold attachment region isolated from a tobacco gene, and a method of making recombinant cells having increased levels of expression of foreign genes therein, are described. The method comprises transforming the cell with a DNA construct comprising in the 5' to 3' direction, a transcription initiation region, a structural gene positioned downstream from the transcription initiation region and operatively associated therewith, and a scaffold attachment region of the nucleotide sequence provided herein, positioned either 5' to the transcription initiation region or 3' to the structural gene. DNA constructs and vectors employed in carrying out the foregoing method are also discussed.

Abstract: An isolated DNA fragment comprising a mammary gland-specific promoter is disclosed. Preferably, this promoter promotes gene expression throughout the estrous cycle in a constant manner. In one embodiment, the promoter comprises nucleotides 1154 through 2967 of SEQ ID NO:1 or 1102 through 2910 of SEQ ID NO:2.