presentacion de dos noticias sobre el DNA y las bacterias para la clase de biologia molecular, tercer semestre de medicina, agosto 2014

1. Researchers create the
first model of the DNA
“replication fork”
-and-
Sequencing efeforts miss
DNA crucial to bacteria’s
disease causing power
Sergio Andrés Correa Hernández
3 semester, molecular biology
Teacher: Lina María Martinez
Universidad Pontificia Bolivariana
11/08/2014 Medellín

4. Introduction
• The genetic changes which happen in
the DNA are important for the
mutation of all the earth organisms, so
the study of this molecule is very
interesting because it leave us know
how the mutations and the captation
of new pieces of DNA from the
exterior are happening and make us
understand how the diseases happen
to give the right attention and do the
correct treatment to them.

5. Researchers create the first
model of the DNA
“replication fork”
• This experiment was made in a
test tube where they brought
together nucleotides, a double-
stranded molecule of DNA and
the enzymes essential for the
process, taken from yeast, an
eukaryotic fungi.

6. Researchers create the first model of
the DNA “replication fork”
The important point of the investigation is that
this model can allow the researchers to view
directly the process of the replication of the
DNA, comparing both chains of the DNA, the
leading and the lagging, and identified how is
the replication process with two differents
enzymes, one for the leading chain, and other
for the lagging chain.

7. Researchers create the first model of
the DNA “replication fork”
• The researches already know how is the
replication fork, which the compare with a
zipper opening because of the slider and
separation process which the DNA suffer.
• Even with this new model, the exact process
of passing the information still being a
mystery.

8. Researchers create the first model of
the DNA “replication fork”
• The researchers think this model of the DNA
replication fork could be the key to unravel
some secrets of the DNA as epigenetic and the
reparation of the DNA.
• They hope this investigation open
opportunities for many laboratories to
research about the DNA chains and the
process who take place on his replication.

9. Personal comment
• This investigation looks like is going to change
the point of view about the DNA lagging chain
replication and the process of the reparation
which is made by the DNA polymerase B, but i
give special attention to the second process
because this could be the answer to the
genetic diseases and if the human can remake
it better than it is, we can think on the
reparation of a 21 chromosome trisomy, or a
genetic therapy before have children.

10. Sequencing efeforts miss
DNA crucial to bacteria’s
disease causing power
• The base of this experiment is that in
the past investigations, all the
laboratory leave some particles of
non chromosomal DNA out of the
research, so, they change the
technique to reveal those
extrachromosomal DNA and to study
them, the organism they use is the
Staphylococcus aureus which can
cause mortal diseases in the right
conditions.

11. Sequencing efeforts miss DNA crucial
to bacteria’s disease causing power
Before the technique was not used because in the
process to take the DNA, was natural that the
shows become contaminated, to solve this
problem, the researchers take a phage tool, the
enzymes which phages use to break the cell and
free the protein.
This process was made with 24 strains of
Staphylococcus aureus taking softly the
extrachromosomal DNA and leaving the others DNA
components out of the investigation.

12. Sequencing efeforts miss DNA crucial
to bacteria’s disease causing power
• One of the results of the investigation was
decodification the phage DNA, where the
researchers find a number of genes which may
help the phago to go inside the inmune
system of the host and pass to other
staphylococcus making a bacteria so much
more dangerous.

13. Sequencing efeforts miss DNA crucial
to bacteria’s disease causing power
• But the implications of this phago genes go
beyond the phatogenicity, for example the
researches find som genes which could
determinate the silence of a bacteria going
inside the chromosomal DNA, a show of this is
they find 2 transient elements which easily
can be inside or outside the charomosoma.

14. Sequencing efeforts miss DNA crucial
to bacteria’s disease causing power
personal comment
• This experiment is important because some
known bacterias are getting powerful with the
antibiotic resistance and this research could
show how is the mechanism of the phagos to
give the resistance to the bacterias and pass
to them making all resistant to the antibiotics,
and knowing this mechanism could be created
medicines to make front of them and end with
the antibiotic resistance.

15. Medical utility
• For this investigation is important
know the full replication DNA
system to know how act in front of
a mutation or know act to prevent
the mutations.

16. Medical utility
Even we can talk now about the function in the war of the
biological weapons, weapons who could be controlled
knowing his action system and puting a barrier to them
creating medicines to prevent mutations or overproduction
of some proteins or Neurotransmissor in case of a biological
attack.

17. Medical utility
The medical utility of knowing the
mechanisms of bactierial resistence
is passed to the others can make
people reproduce a mechanism to
stop his «reproduction» of the
resistence.

18. Medical utility
The investigation of the
extrachromosomal DNA
genes can open a new
world of knowledge
about how the virus are
passed by humans or
animals, an that new
knowledge could show us
more than we are
expecting, like a new way
for virus for propagation.

19. References
[http://newswire.rockefeller.eu/2014/06/25/
sequencing-efforts-miss-dna-cricial-to-
bacterias-disiase-causing-power/] checked on
7/08/2014 at 16:16 “Sequencing efforts miss
DNA crucial to bacteria’s disease causing
power”
[http://www.sciencedaily.com/r
eleases/2014/07/140709100106.
htm] checked on 07/08/2014 at
16:12. “Researchers create the
first model of the DNA
‘replication fork”

20. despedida