Expression and amplification in transgenic mice of a polyoma virus mutant regulatory region.
Two hybrid gene constructs consisting of wild-type and mutant polyoma regulatory regions fused to a bacterial reporter gene were inserted in the mouse germline. Both transgenes were expressed in a large number of different organs. However, marker gene expression controlled by the polyoma wild-type regulatory region was not detectable in the early embryo and remained low throughout the life of the animal while expression controlled by the polyoma F9-1 mutation was detectable in blastocysts and was significantly higher at later stages of development. The F9-1 hybrid gene was also amplifiable when large T-antigen was supplied in trans to mice or to kidney cells derived from these transgenic mice. Amplification resulted in the appearance of several hundred copies of episomal transgenes and a marked increase of marker gene RNA and protein. Our results suggest that the F9-1 mutation does not alter the target spectrum of gene expression in vivo but does create a more efficient enhancer element in the polyoma early control region. Transgene amplification based upon use of the polyoma regulatory elements may be a means of increasing expression of genes in transgenic mice.
Krippl
B
B
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Griep
A E
AE
Mahon
K A
KA
Böhnlein
E
E
Gruss
P
P
Westphal
H
H
D000367:Age Factors; D000818:Animals; D001755:Blastocyst / Q000201:enzymology; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004742:Enhancer Elements, Genetic; D005784:Gene Amplification; D005786:Gene Expression Regulation; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics*; D011120:Polyomavirus / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014018:Tissue Distribution
D015500:Chloramphenicol O-Acetyltransferase