Control of transgenesis in higher cells: the procell transposon Tn10 TetR mRNA has several major hairpins and can be unstable in eucells.

Abstract

The TetR regulatory gene from the transposon Tn10 has some excellent characteristics for transgenic control in higher cells. However, we experienced severe problems with mRNA instability for this gene in eucells (CHO cells). This may be connected with the existence within the Tn10 TetR mRNA of several sizeable hairpins. They resemble canonical RNase E sites for mRNA destabilisation in procells and possibly also in eucells. Two of the hairpins also included sequences resembling eucell hnRNA polyadenylation or processing signals. The TetR counterpart from the plasmid RA1 appears to have less of the hairpin secondary structure; perhaps because of this, it did not present these mRNA instability problems in CHO cells, and it may prove a valuable alternative for transgene control in gene therapy and biotechnology.