Manuela Vélez Gaviria

Medicine Student – 3rd Semester

Universidad Pontificia Bolivariana

Medellin, 2012.

Z-DNA found in

nucleosomes and in the

active transcription sites

is a step towards the

regulation of gene

expression.

The schmidtea

mediterranea is a worm

able to regenerate

despite not having

centrosomes in the cells.

ELUSIVE Z-DNA FOUND ON NUCLEOSOMESSCIENCEDAILY (JAN. 20, 2012)

ELUSIVE Z-DNA FOUND ON NUCLEOSOMES

SCIENCEDAILY (JAN. 20, 2012)

Z-DNA is a possible

biologically active

form of

DNA, according to

research; Z-DNA is

present in

nucleosomes and at

sites of active

transcription.

ELUSIVE Z-DNA FOUND ON NUCLEOSOMES

SCIENCEDAILY (JAN. 20, 2012)

Was discovered that is possible to

form Z-DNA from a family of

proteins (SWI/SNF) involved in the

remodeling of nucleosomes, that is

to say, change of position of the

nucleosome along the DNA.

The SWI/SNF proteins have an

ATPase activity able to hydrolyze

ATP generating ADP+Pi and

energy which is used to remodel

the nucleosomes

ELUSIVE Z-DNA FOUND ON NUCLEOSOMES

SCIENCEDAILY (JAN. 20, 2012)

The presence of Z-DNA in nucleosomes is very

important for the remodeling of chromosomes and

the regulation of transcription process.

STUDENT OBSERVATION

DNA is the structure in which life is contained, it has attracted the interest of numerous researchers

throughout history, but although there have been several and extraordinary advances, still missing pieces to complete the puzzle, that is why, in my

opinion, this news is important because it gives a step closer to mechanisms that can help the process of

transcription regulation fundamental in gene expression.

FLATWORM FLOUTS FUNDAMENTAL RULE

OF BIOLOGY: WORM REGENERATES

WITHOUT CENTROSOME, A STRUCTURE

LONG THOUGHT NECESSARY FOR CELL

DIVISION

SCIENCEDAILY (JAN. 5, 2012)

FLATWORM FLOUTS FUNDAMENTAL RULE OF BIOLOGY: WORM

REGENERATES WITHOUT CENTROSOME, A STRUCTURE LONG THOUGHT

NECESSARY FOR CELL DIVISION

SCIENCEDAILY (JAN. 5, 2012)

The centrosome is the

major microtubule

organizing center in

animal cells, which

contribute to the division

of chromosomes into

chromatids and

cytokinesis, it is for this

reason and its relation to

cell motility is regarded

as a necessary structure

in the cell division.

FLATWORM FLOUTS FUNDAMENTAL RULE OF BIOLOGY: WORM

REGENERATES WITHOUT CENTROSOME, A STRUCTURE LONG THOUGHT

NECESSARY FOR CELL DIVISION

SCIENCEDAILY (JAN. 5, 2012)

The schmidtea mediterranea is a worm with a great capacity to regenerate itself that’s why it was selected to study what happens in it after manipulates their centrosomes to destroy.

Was observed that the worm successfully regenerated, which led to even more detailed analysis finally showed the absence of centrosomes in the species treated from the beginning.

FLATWORM FLOUTS FUNDAMENTAL RULE OF BIOLOGY: WORM

REGENERATES WITHOUT CENTROSOME, A STRUCTURE LONG THOUGHT

NECESSARY FOR CELL DIVISION

SCIENCEDAILY (JAN. 5, 2012)

The fact that the worm has the ability to regenerate

agility without the presence of centrosomes makes

you question the function of the centrosome in the

process of cell division… Is there something more

to be discovered?

STUDENT OBSERVATION

Mechanisms of self-replication are one of the fundamental properties of eukaryotic cells and also are the basis to understand several pathologies; I think is really important to look into the role of the

centrosome in cell division and why a species with a large capacity of regeneration, as it is the schmidtea

mediterranea, not have centrosomes, believed absolutely necessary for the processes of cell

division and regeneration.

Increasingly understand the processes of

replication, translation and transcription in this case, is the

possibility of regulating the expression of proteins and gene

expression, using this as a basis to reach the bottom of

hereditary diseases or defects related to any of the steps of

gene expression and find possible treatments.

Adequate cell replication and the control of this

constitute much of the health state of humans; an

alteration in the cell division can generate a lot of

diseases as cancer, therefore, knowledge and

research-oriented, self-replication mechanisms

provide alternatives for the treatment and possible

cure of the many diseases.

BIBLIOGRAPHY

Elusive Z-DNA found on nucleosomes [ online ]

<http://www.sciencedaily.com/releases/2012/01/120

120183042.htm >[Tuesday January 24, 2012 ].

Flatworm Flouts Fundamental Rule of Biology:

Worm Regenerates Without Centrosome, a

Structure Long Thought Necessary for Cell Division

[ online ]

<http://www.sciencedaily.com/releases/2012/01/120

105174220.htm> [Tuesday January 24, 2012 ].