Chalmers Conferences, 9th European Conference on Mathematical and Theoretical Biology

Regulating Looping in
Anirvan Sengupta

Last modified: 2014-06-09


Regions of the chromosome that are many thousands of bases away often
have to come in contact for turning some genes on or off. The
specificity of such contacts is maintained by interposed boundaries or
insulators, which are able to block these long distance interactions.
The physical basis for the control of chromatin contact is still not
well understood. We model the chromatin fiber as a semi-flexible polymer
to explain how 'distant' regulatory interaction happens and how it is
controlled by other sequence elements. There appears be region in the of
parameters space of where mesoscopic attractive polymers fold to form
branched polymer like structures, which are key to understanding our
results. We will explore the connection between this regime and
disordered systems treated by large N expansion. We finish by discussing
how we could use the polymer model of chromatin to analyze data related
to chromatin conformation and learn about regulatory contacts.