A presentation by Thatayaone Ezekiel Dinama, Kago Relaeng and Michael Moseneke made to the Cardiff Sixth Form College A-Level BioMedical Society on the amazing discovery of the G-Quadruple structure of DNA. The discovery has many unfathomable potential benefits as far as health is concerned. Being interested in studying Medicine (Clinical or Academic) I found it a really intriguing research topic of recent times.

1. QUADRUPLE DNA HELIX
THE DISCOVERY
EZEKIEL , KAGO , MICHAEL

2. Road to the discovery of DNA
-1969
DNA isolated by Swiss Physician Friedrich Meisches, who,
discovered a microscopic substance in the puss of
discarded surgical bandages. As it resided in the nuclei
of cells, he called it nuclein.
-1878
Albsecht Kossel isolates the non-protein component of
the protein and later isolates its five primary
nucleobases.
-1919
Phoebus Leven identifies the base, sugar and phosphate
nucleotide unit.

3. Road to the discovery of DNA
-1937
William Asthry produces the first X-ray diffraction
pattern that showed DNA had a regular structure.
-1953(phew!!)
James D Waston and Francis Crick suggested what is now
accepted as the double helix, based on a single X-ray
diffraction image (Rosalind Franklin and Raymond
Crossling)

4. Nucleotides and protein
sequences
(BY1 stuff, so you obviously know it )
60 years later……G-quadriplex structure discovered in
human cells

5. THE G-QUADRIPLEX

6. How??
-Intertwine four, rather than two
-Use of fluorescent antibody that attaches exclusively to
G-quadruplexes(stop them from unraveling into the
ordinary DNA)
-Enabled the researchers to count how many formed at
each stage of cell multiplication.
-A marked increase was shown when the fluorescent
staining grew more intense during the 's-phase‘
-Exist in cancer cells and normal cells.

7. For the Future
Cancer treatment
Cancers are usually driven by genes called oncogenes
that have mutated to increase DNA replication - causing
cell proliferation to spiral out of control, and leading to
tumour growth. The increased DNA replication rate
during oncogenesis leads to an intensity in the
quadruplex structures.
Therefore if the cancerous cells are exposed to
pyridostatin, a molecule that traps quadruple helices
wherever they form, it would lead to interruption in
synthesis, hence control of cancerous cells.

8. For the Future
Personalised Medicine.
Through the branch of Bioinformatics, the discovery can
lead to assimilation of even more specific genome into
the intergrated computers for improved diagnosis.

9. Professor Shankar Balasubramanian
“"I hope our discovery challenges the
dogma that we really understand
DNA structure because Watson and
Crick solved it in 1953”

10. THANKS 