Cryptic polyadenylation sites within the coding sequence of three yeast genes expressed in tobacco

Three yeast genes, MIP (mitochondrial DNA polymerase) and two genes, YCF1 ( yeast cadmium factor 1) and PDR5 (pleiotropic drug resistance 5), conferrin g multidrug resistance, were provided with the cauliflower mosaic virus 35S transcription promoter and introduced into tobacco using an Agrobacterium tumefaciens T-DNA-derived vector. Transcripts of each gene much shorter tha n those expected were found in the transgenic plants. RT-PCR and S-1 nuclea se mapping of the PDR5 and MIP transcripts demonstrated the presence of one (PDR5), or several close (MIP), cryptic polyadenylation site(s) within the coding sequence of these yeast genes. Possible sequences involved in polya denylation are discussed. (C) 2000 Elsevier Science B.V. All rights reserve d.