The effect of insertion of the bGH polyadenylation signal into the 5' LTR. The bGH polyadenylation signal was inserted into the 5' LTR with (pRK2DSE), or without (pRK2), the downstream regulatory element and vector titres assessed. (A) Sequence of insertions made. The AATAAA motif is shown bold and the bGH sequence is underlined. (B) Vector titres using 1 ug vector per well. * = P < 0.05 vs pRK1Δatt340/184 ANOVA on Ranks with Dunns Multiple Comparison All results are presented as Mean ± SD (n = 6).