Auckland Cancer Society Research Centre seminar: Following genome organization and gene expression through the cell cycle Event as iCalendar

27 September 2013

1 - 2pm

Venue: Lecture Theatre 505-011, AMRF Auditorium, Building 505, 85 Park Road, Grafton

The three and four dimensional organization of genomes is becoming increasingly recognized as a key contributor to genome maintenance and gene regulation. However, most high resolution studies of genome organization have been performed on multicellular organisms or asynchronous cell populations. Mixed tissues and asynchronicity, together with the dynamic nature of chromatin, may cloud our understanding of the genome structure:function relationship. In this study we used synchronised Schizosaccharomyces pombe cells to investigate how genome organization changes during the cell cycle and if these changes contribute to cell cycle specific transcription patterns.

Pairwise genome structures and transcript levels were determined for highly synchronized cell populations, in the G1, G2 and M phases of the cell cycle, using Genome Conformation Capture (GCC) and RNA sequencing. Global differences in genome organization were observed for the three cell cycle phases, with notable variation in inter-chromosomal telomere clustering. Furthermore, repeat regions in the genome appear to demarcate domains within and between chromosomes. Genes with transcript levels that were consistently high or low throughout the cell cycle, interacted with each other and the rest of the genome at a level no different to or lower than expected by random chance at all stages of the cell cycle. In contrast, genes that were differentially regulated during cell cycle transitions were found to interact with each other and the rest of the genome at a level higher or lower than random chance at specific stages of the cell cycle. Additionally, the differentially regulated genes that were highly clustered during the G1 – G2 and G2 – M phase cell cycle transitions had a non-random linear chromosomal distribution.

Collectively, our results highlight that genome organization is dynamic throughout the cell cycle and signify the potential importance of using synchronized cell population for the study of spatial genome organization. Furthermore, the finding that differentially regulated genes that exhibit variable clustering at different cell cycle phases also have a non-random linear chromosomal distribution supports the linear and spatial clustering of co-regulated genes.

presented by: Justin O’Sullivan

Justin O'Sullivan completed his PhD at The University of Otago (NZ) in 1998, he held postdoctoral positions at the University of Kent and the University of Oxford in the UK.

He returned to New Zealand in 2004 to take up a faculty position at Massey University, and moved to the Liggins Institute in 2012.

his group published the first method to determine the global genome interaction network, and has described a novel DNA interaction pathway between mitochondria and the nucleus. He also utilise modelling approaches to construct three-dimensional maps of the nucleus from interaction data.


For more information please contact:

Dr Jack Flanagan Email: j.flanagan@auckland.ac.nz