GENE-REGULATION BY ANTISENSE DNA PRODUCED IN-VIVO

Antisense technology has been widely used for regulating gene expressi on, Single-stranded RNA or DNA complementary to a target mRNA can inhi bit the translation of the mRNA. Antisense RNA is produced in vivo, wh ile antisense DNA is chemically synthesized as an oligonucleotide, whi ch is extracellularly added to the cells, To maintain the effect of an tisense DNA, a synthetic oligonucleotide has to be constantly added to the system, An advantage of antisense DNA over antisense RNA is that the target mRNA hybridized with the antisense DNA can be specifically digested by ribonuclease H. Here, we attempted to produce in vivo shor t single-stranded DNAs complementary to a specific mRNA. We demonstrat e that such antisense oligodeoxyribonucleotide of a desired sequence c an be produced in Escherichia coil using a retron, a bacterial retroel ement, as a vector and that the antisense DNA thus produced in vivo ca n effectively inhibit the expression of a specific E, coil gene, such as the gene for the major outer membrane lipoprotein.