1. A. THE GLOBAL SCENE

2. RNA Interference and RNA Silencing
• RNA Interference (RNAi)- is a highly
evolutionally conserved process of post-
transcriptional gene silencing (PTGS) by
which double stranded RNA (dsRNA),
when introduced into a cell, causes
sequence-specific degradation of
homogolous mRNA sequences.

3. • 1998- it was introduced by Andrew Fire
and Craig Mello in the nematode worm
Caenorhabditis elegans and later found
in a wide variety of organisms, including
mamals.
• RNAi is believed to be universal as it
has been observed in all eukaryotes, from
yeast to mamals.

4. The most interesting aspects of RNAi are
the following:
• dsRNA, rather than single-stranded
antisense RNA, is the interfering agent.
• It is highly specific
• It is remarkably potent
• the interfering activity can cause
interference in cells and tissues far
removed from the site of introduction.

5. Application of RNAi
1. Determining Gene Function
2. Pathway Analysis
3. Identify and Validate drug Targets
4. Study Gene Redundancy
5. Functional Screening

6. RNA Timeline

7. Timelin Who What Organism
e
Guo S, and First noticed that sense RNA was
1995 Kemphues KJ. as effective as antisense C. elegans
RNA for Suppressing Gene
expression in worm
First described RNAi Phenomenon
1998 Fire et al. in C. elegans by injecting dsRNA
into C. elegans which led to an C. elegans
efficient sequence- specific
silencing and coined the term
“RNA Interference”.
Reported processing of long dsRNA
2000 Zamore et al. by Rnase II (Dicer) into shorter Drosophila
fragments of 21-23-nt intervals in
Drosophila extracts

8. Cloned Dicer, the Rnase III enzyme that is
2001 Bernstein et al. evolutionarily conserved and contains C. elegans
helicase and PAZ domains, as well as two
dsRNA- Binding domains.
2001 Tuschl T and Mammals
colleagues First described RNAi in Mammalian cells.
2003 Paddison et al. Short hairpin RNAs (shRNAs) induce Mammals
Sui et al. sequence- specific silencing in mamalian
cells.
Paul et al.
2003 First reported that siRNAs can be used Mammals
Song et al. therapeutically in whole animals.
2004 Kawasaki and First observed that siRNA silences gene at Human
Taira transcriptional level possibly through
Morris et al. directing de novo DNA methylation.
Andrew Fire Won Noble Prize in Physiology or Medicine Human
2006 and for discovering RNAi mechanism.
Craig Mello
2006 Li et al First reported that small dsRNA induces Human
gene expresion activation, a phenomenon
termed as RNAa.

9. DNA Microarray Technology?
• DNA Microarray Technology- have
been developed in the 1990's as a
method of rapidly analyzing the
expression of thousands of genes all at
the same time by allowing the RNA
products of genes to be monitored at
once.

10. How do DNA microarrays work?
• DNA microarray work by providing
fixed single strands of Dna (gene
sequences) to which labeled cDNA
fragments can bind. Thousands of
different genes are immobilized onto ma
small, inert, solid support (called a chip),
which is usually a glass microscope slide,
but can also be a silicon chip or a nylon
membrane.

11. Application of DNA microarrays work?
• Correlating Gene Expression with
metabolic Changes
• Characterizing nCell Types
• Cancer Research
• Toxicology

12. FBI CODIS (Combined DNA Index
System) for Human Identification
• In 1997 the US FBI (Federal Bureau of
Investigation) Selected thirteen STR
(Short Tandem Repeat) loci in human
chromosomes foe use as standards in
human identification and genome
signature comparison.

13. Why use STRs (Short Tandem Repeats)?
• Short Tandem Repeats (STRs) offer
several advantages over RFLPs as tools
for human identification.
• STRs exhibit high heterozygosity
• STRs exhibit a regular repeat pattern
• STRs are easily amplified

14. IV. Nanotechnology
• Nanotechnology- refers to the design,
characterization, production and
application of structures, devices and
systems by controlling shape and size at
nanometer scale.
• Nano- is derived from the greek word
“dwarf”.

15. Bioinformatics: Shaping the Future of
Biotechnology
• Blast- is an algorithm that stands for
Basic Local Alignment Search Tool and
was developed by Altschul, Gish, Miller,
Myers, and Lipman in 1990.
• It is used to search for related
sequences available in the database
and for comparing two or more
sequences for similarities.

16. Application in Biotechnology
Research
• Agriculture
• Aquaculture
• Human Health
• Environment
• Wildlife Conservation
• Industry
• Forensics