Skip to main content
ARS Home » Research » Publications at this Location » Publication #65811
Title: CRITICAL TRANSCRIPTION ELEMENTS WITH 1 KB OF THE WHEY ACIDIC PROTEIN GENE PROMOTER ARE ONLY ACTIVE IN THE PRESENCE OF A MATRIX ATTACHMENT REGION.

Author
item MCKNIGHT, ROBERT - NIH
item Spencer, Mark
item Wall, Robert
item HENNINGHAUSEN, LOTHAR - NIH

Submitted to: Journal of Molecular Reproduction and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Embedded within genes are DNA sequences that specify in which tissue a gene will be active. In an attempt to identify the tissue specifying elements in genes that only function in mammary glands we modified mouse gene encoding the whey acidic protein and used the modified gene (mWAP-mini) to product transgenic mice. The modification entailed removing all but 1,000 bases of the punitive regulatory elements of WAP. The WAP-mini gene functioned in only one of 17 transgenic mice analyzed, implying that we have successfully removed the critical sequences that control WAP function. However to ensure that this result was not an artifact sometimes observed in transgenic animals we repeated the experiment after adding matrix attachment region sequences, which "protect" transgene, to WAP-mini. This time the modified gene functioned properly in seven out of nine transgenic lines tested. These results taken together suggest that critical control elements specifying mammary gland function reside within the first 1,000 bases of the WAP gene, but some elements more distal are rsponsible for enhancing WAP gene function. Finally when we made transgenic mice with rat WAP gene modified in the same way and it functioned normally. Inspection of the differernces in DNA sequences between the mouse and rat WAP genes has provided provided some insight into what the enhancer element of the mouse WAP gene may look like.

Technical Abstract: Matrix attachment regions (MAR) have been shown to participate in the insulation of transcription elements from surrounding chromatin in tissue culture cells and in transgenic animals. We demonstrated earlier that a mouse whey acidic protein (WAP) transgene with 2.4 kb of promoter sequence was active in only 40% of the mouse lines. In the presence of MAR sequences from the chicken lysozyme gene expression of transgenes was observed in all lines. Here we provide evidence that DNA elements conveying mammary specificity and developmental signals to the mouse WAP gene are located with a 1 kb promoter fragment. However, the WAP transgene with a 1 kb promoter was active in only 1 out of 17 lines of mice. When MAR sequences from the chicken lysozyme gene were linked to the WAP transgene, 7 of the 9 lines generated exhibited WAP transgene activity. Expression was confined to mammary tissue and correct regulation occurred in 3 of the 4 lines analyzed. This study provides additional evidence that the MAR fragments from the chicken lysozyme gene have the capacity to insulate transgenes from position effects.