SEMINAR @ SISSA, SBP, dr. A. Rosa - April 29, at 17.00 hrs.

[Barbara Corzani]

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STATISTICAL AND BIOLOGICAL PHYSICS SEMINAR
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Dott. A. Rosa
(Zaragoza)

Title:
"Structure and Dynamics of Interphase Chromosomes: A Novel Polymer Physics Approach"

Thu 29 April 2010 @ 05.00 p.m.

SISSA - Basement floor - room A
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Abstract:
During cell cycle, eukaryotic chromosomes undergo a series of structural
rearrangements:
1) during mitosis (cell division) they assume a rod-like shape and stay
maximally compacted;
2) during interphase (normal cell activity) they decondense inside the
nucleus and occupy discrete territories which play a pivotal role in
gene expression and regulation [1].
A general consensus about the mechanisms regulating chromosome
organization at each phase of the cell cycle is still lacking.
Several experimental techniques have been recently put forward with the
goal to fill this gap:
1) Fluorescent in-situ Hybridization [1] and Chromosome Conformation
Capture [2] are employed to monitor chromosome organization and detect
specific interactions between chromatin fibers;
2) Fluorescent marking of selected genomic sequences monitor the in-vivo
chromatin dynamics [3].
As a consequence, an enormous amount of structural and dynamical data is
nowadays available: hence, the next challenge appears the organization
of these data into a consistent framework.

Recently, we have proposed a coarse-grained generic polymer model of
decondensing chromosomes [4,5].
The model captures "quantitatively" currently available experimental
data about chromosome structure and dynamics during interphase. In
particular, in our framework territories "naturally" appear as the
consequence of the incomplete relaxation of long, mutually unentangled
chromatin fibers.
In this talk:
1) we discuss the details of our work and
2) we present a series of open problems, which we have left to future
investigations.

References:
[1] Cremer & Cremer, Nature Rev Genet (2001)
[2] Dekker et al., Science (2002)
[3] Gasser, Science (2002)
[4] Rosa & Everaers, Plos Comput Biol (2008)
[5] Rosa et al, Biophys J (2010)