A PLANT SCAFFOLD ATTACKED REGION DETECTED CLOSE TO A T-DNA INTEGRATION SITE IS ACTIVE IN MAMMALIAN-CELLS

Integration of foreign genes into plant genomes by the Agrobacteriom T -DNA transfer system has been considered to occur at random. It has be en speculated that the chromosomal structure of the integration site m ight affect the expression pattern of the introduced genes. To gain in sight into the molecular structure of T-DNA integration sites and its possible impact on gene expression, we have examined plant DNA sequenc es in the vicinity of T-DNA borders. Analysis of a transgenic petunia plant containing a chloramphenicol acetyltransferase (CAT) gene regula ted by the hemoglobin promoter (PAR) from Parasponia andersonii reveal ed a scaffold attachment region (SAR) close to one T-DNA end. In addit ion to having strong binding affinities for both animal and plant nucl ear scaffolds this petunia SAR element is as active in mammalian cells as the authentic elements from mammalian sources.