1. ANTISENSE RNA Desh Bandhu 10/pbt/006

2. INTRODUCTION Antisense RNA is a single-stranded RNA that is complementary to a messenger RNA (mRNA) strand transcribed within a cell. Antisense RNA may be introduced into a cell to inhibit translation of a complementary mRNA by base pairing to it and physically obstructing the translation machinery. An example of naturally occurring mRNA antisense mechanism is the hok/sok system of the E.coli R1 plasmid.

3. INVITRO MECHANISM

4. Hok/sok system(Natural mechanism) The hok/sok system involves three genes: hok, host killing - a long lived (half-life 20 minutes) toxin. sok, suppression of killing - a short lived (half-life 30 seconds) RNA antitoxin mok, modulation of killing - required for hok translation

6. ROLE OF ANTESENSE RNA To inactivate the polygalacturonase gene. To inactivate ethylene synthesis. Reduction of starch content in vegetables. Modification of flower colour in various decorative plant. Mammalian genomes encode numerous natural antisense transcripts, but the function of these transcripts is not well understood.

7. FUTURE PROSPECTS In Gene therapy. To develop more effective therapies for infection with certain virus such as HIV and hepapetitis B virus. To reduced the elevated blood pressure.