| 摘要 |
<p>Polynucleotides and vectors comprising an expressible nucleic acid flanked by a 5' extended methylation-free CpG island and a 3' selectable marker element are disclosed. Such polynucleotides and vectors provide a means for obtaining high levels of expression of the flanked expressible nucleic acid. Preferred embodiments include combinations of 5' extended methylation-free CpG islands and 3' antibiotic resistance genes.</p> |
