Plant cells do not properly recognize animal gene polyadenylation signals

We have introduced chimeric genes containing polyadenylation signals from a human gene and two animal virus genes into tobacco cells. We see, in all three cases, inefficient and 'aberrant' utilization of the foreign polyadenylation signals. We find that a chimeric gene carrying the polyadenylation site of the human growth hormone gene is polyadenylated at three sites in the vicinity of the site that is polyadenylated in human cells. A chimeric gene containing the polyadenylation site from the adenovirus 5 E1A gene is polyadenylated at a site 11 bases downstream from that reported in animal cells. A gene carrying the polyadenylation site from the SV40 early region is polyadenylated some 80 bases upstream from the site that is polyadenylated in animal cells. In all three cases, related mRNAs ending at flanking 'authentic' plant polyadenylation sites can be detected, indicating that the foreign polyadenylation signals are inefficiently utilized in tobacco cells.