Date of Award

1-1-2012

Document Type

Masters Thesis

Degree Name

M.S.

Organizational Unit

College of Natual Science and Mathematics

First Advisor

Dinah Loerke, Ph.D.

Second Advisor

Mark Siemens

Third Advisor

Kingshuk Ghosh

Keywords

Motion of particles, Chromatin motion, Proliferating cell nuclear antigen

Abstract

Motion of particles under influencing forces may be observed under light microscopy techniques. Variations in mobility of particles may give relevant biophysical information. Automated high resolution single particle tracking techniques were used to characterize interphase chromatin mobility in the cell nucleus. Interphase chromatin undergo replication prior to cell division with the assistance of replication proteins (machinery) which modify chromatin mobility. Using dual color imaging of flourescently tagged chromatin and proliferating cell nuclear antigen (PCNA) were followed through interphase. Chromatin motion was modelled as a two dimensional random walk. Reduction in chromatin mobility was observed during S phase was dependent on proximity to the replication machinery. Mobility during G1 and G2 phase is independent of proximity to GFP-PCNA maxima and is higher than during S phase. These results suggest that replication selectively inhibits chromatin mobility. Local proximity to replication machinery however, cannot account for the entire mobility difference. By modelling the mean square displacement as a power law, sub-diffusive behavior was observed in S phase chromatin whereas non S phase exhibited normal diffusional characteristics.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Rights Holder

Matthew Joel Westacott

Provenance

Received from ProQuest

File Format

application/pdf

Language

en

File Size

46 p.

Discipline

Biophysics

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