DNA is a long polymer of simple units called nucleotides. Each one contains a phosphate group (acid component), a sugar group (neutral component) and a nitrogen base (basic component).

1. 3D ‘printouts’ at the nanoscale using self-assembling DNA
structures
&
Expanding the DNA alphabet: 'Extra' DNA base found to
be stable in mammals
Ana Mercedes Vanegas Torres
3rd Semester
UPB
Teacher: Lina M. Martínez

4. What is the essential molecule for life? The answer is really easy, DNA! It is the
responsible for the growth and maintenance of life, because it holds the instructions
for an organism's development and reproduction
DNA is a long polymer of simple units called nucleotides, which are held together by
a backbone made of sugars and phosphate groups.
This backbone carries four types of molecules called bases and it is the sequence of
these four bases that encodes information. The main role of DNA in the cell is the
long-term storage of information.
If this molecule has any change, our cells starts working incorrectly triggering a
disease.

5. 3D ‘printouts’ at the nanoscale using self-assembling DNA
structures(July 23,2015)
There is a new technique that makes
possible to synthesize 3D DNA
origami structures that are also able
to tolerate the low salt
concentrations inside the body
This opens the way for completely new
biological applications of DNA
nanotechnology
“We can now make structures that
were impossible to design previously
and we can do it in the same way as
one might draw a 3D structure for
printing out in macroscopic scale, but
instead of making it out of plastic, we
print it in DNA at the nanoscale.”

6. How is this new technique developed?
The user draws the desired structure, in
the form of a polygon object, in 3D
software
They calculate the DNA
sequences needed to produce
the structure using graph-
theoretic algorithms and
optimization techniques
The synthesized DNA sequences are
combined in a salt solution They assemble themselves into
the correct structure.
Using this technique, the team has built a ball,
spiral, rod and bottle-shaped structure, and a
DNA printout of the so-called Stanford Bunny,
which is a common test model for 3D modelling.

7. “An advantage of the automated design process is that one can now deal systematically with even
quite complex structures. Advanced computing methods are likely to be a key enabler in the scaling of
DNA nanotechnology from fundamental studies towards groundbreaking applications,” says Professor
Pekka Orponen, who directed the team at the Aalto University Computer Science Department.

8. What are the possible applications ?
The team at
Karolinska Institutet
has previously made
a DNA nano-caliper
used for studying cell
signalling.
The new technique makes it
possible to conduct similar
biological experiments in a
way that resembles
conditions within cells even
more closely.

9. I have
something
to say
In my opinion this discovery is a great contribution to
modern medicine, because doctors and scientists
hope to use our genetic information to diagnose,
treat, prevent and cure many illnesses. That’s why, I
think that we should investigate more about DNA
structure, because if we learn more about life at the
level of atoms and molecules we could identify
specific explanation of many diseases and treat the
real cause.

10. Expanding the DNA alphabet: 'Extra' DNA base found to be stable
in mammals(June 22, 2015)
Researchers from the University of Cambridge and
the Babraham Institute have found that a naturally
occurring modified DNA base appears to be stably
incorporated in the DNA of many mammalian tissues,
possibly representing an expansion of the functional
DNA alphabet.
'This modification to DNA is found in very specific
positions in the genome -- the places which regulate
genes,' said the paper's lead author Dr. Martin
Bachman

11. They have found a rare 'extra' base, known as 5-formylcytosine
(5fC)
In addition to the DNA bases G, C, A and T, there are also small chemical modifications, or epigenetic
marks, which affect how the DNA sequence is interpreted and control how certain genes are switched
on or off.
It had been thought that 5fC was a 'transitional'
state of the cytosine base which was then being
removed from DNA by dedicated repair enzymes.
5fC
Epigenetic mark
When TET enzymes add oxygen to methylated DNA * It is a DNA molecule with
smaller molecules of methyl
attached to the cytosine
base
However, this new research has found that 5fC
can actually be stable in living tissue, making it
likely that it plays a key role in the genome.

12. They feed some cells and living mice with an amino
acid called L-methionine, enriched for naturally
occurring stable isotopes of carbon and hydrogen.
Method applied by the researchers
Then they measure the uptake of these
isotopes to 5fC in DNA.
The lack of uptake in the non-dividing
adult brain tissue pointed to the fact
that 5fC can be a stable modification:
if it was a transient molecule, this
uptake of isotopes would be high.

13. The researchers believe that 5fC might alter the way DNA is recognised by
proteins. 'Unmodified DNA interacts with a specific set of proteins, and the
presence of 5fC could change these interactions either directly or indirectly
by changing the shape of the DNA duplex,' said Bachman.
'A different shape means that a DNA molecule could then attract different proteins
and transcription factors, which could in turn change the way that genes are
expressed.'

14. I think that this discovery is really useful
because scientists can look forward for the
real function of this extra base and what
effects causes in our body, telling us if they
are good or bad, keeping in mind that this
'extra' base has a key role in the regulation
of gene expression.

15. Medical Utility
One of the most important applications of DNA
nanostructures is that they have also been used to make
targeted capsules able to deliver cancer drugs direct to
tumour cells, which can reduce the amount of drugs
needed.

16. '5fC will alter the thinking of people in
the study of development and the role
that these modifications may play in
the development of certain diseases,'

17. Thanks to molecular biology, scientists
have observed each one of the
components of the DNA molecule, so
for them it is easy to identify if there is
something wrong, for example if a
part of the molecule is missing and it
causes a specific disease, so they
could treat it and in some cases cure
it.

18. If we know and understand the essential role of DNA in our organism, we
could search for different mechanisms to find the answer to so many diseases
that today apparently doesn’t have any treatment or cure, and in this way
contributing to medical advances.

19. Bibliography
 3D ‘printouts’ at the nanoscale using self-assembling DNA structures,
Karolinska Institutet, 2015. (internet) 2015 Julio (Fecha de acceso Julio 30
de 2015) Disponible en: http://ki.se/en/news/3d-printouts-at-the-
nanoscale-using-self-assembling-dna-structures
 Expanding the DNA alphabet: 'Extra' DNA base found to be stable in
mammals, of Cambridge and the Babraham Institute, 2015. (internet) 2015
Julio (Fecha de acceso Julio 30 de 2015) Disponible en:
http://www.sciencedaily.com/releases/2015/06/150622122726.htm