Dr Rhona Anderson heads the Laboratory of Genome Damage within the Division of Biosciences at Brunel University. The research focus of the Group is to understand mechanisms of radiation-induced carcinogenesis. Of particular interest is the relationship between radiation track structure (varying quality at low doses), chromosome territorial organisation (in space and time) and DNA repair for the induction of chromosome rearrangements of varying complexity.

Chromatin dynamics and exchange formation

Rhona Anderson, Laboratory of Genome Damage, Centre for Cell and Chromosome Biology, Centre for Infection, Immunity and Disease Mechanisms, Division of Biosciences, Brunel University, West London. UB8 3PH, UK Rhona.anderson@brunel.ac.uk

24-colour cytogenetic techniques have provided insight into the characteristic induction of complex aberrations (3 or more breaks in 2 or more chromosomes) after exposure to low doses of high-LET radiation and also after relatively high doses of low-LET radiation, revealing their importance not just as potential biomarkers of radiation exposure and determinants for cellular fate but also as events that further our understanding of the mechanisms of exchange formation. For instance we show for particulate exposure that aberration complexity is a consequence of the number of different chromosome territories intersected by each track meaning complexity is related to the geometry of the nucleus irradiated. In addition, since migration of initially-induced damage is limited by its topological organisation, the density of ionisation events and lesion proximity throughout the nuclear space will also impact on the likelihood that damage can participate in ‘rejoining events’. Such limited migration of damage at the nuclear scale is shown by the constrained dynamics of radiation-induced GFP-53BP1 foci over extended periods of time after exposure and the expectation that exchange aberrations are correlated by the combined surface area of neighbouring territories whereby exchange partners reflect nuclear organisation and territorial neighbourhoods.

By:
Last updated: Monday, 2 July 2012