The TL-DNA in octopine crown-gall tumours codes for seven well-defined polyadenylated transcripts.

Seven polyadenylated transcripts of significantly different relative abundance were detected in octopine crown-gall tissue after gel electrophoretic separation and subsequent transfer to diazobenzyloxymethyl paper. The transcripts range from 670 to 2700 bases long. The different transcripts were located using 19 different fragments of the TL-region as probes. By hybridizing labelled RNA to separated complementary strands of the T-DNA, and parallel determination of the chemical polarity of the strands, the 5' - 3' orientations of six of the seven transcripts was identified. Both strands of the T-DNA code RNA. Hybridization of octopine TL-DNA against poly A RNA's present in two nopaline tumour-lines C58-S1 and BT37, and vice versa, reveals a minimum of two and possibly four transcripts common to both octopine and nopaline tumours. These transcripts originate from corresponding parts of the conserved region of the T-DNA and are of similar size.