UC Santa Cruz

The eukaryotic nucleus is organized in a non-random, organized fashion. The

organization of chromosomes has been found to have a large influence on a diverse

set of processes ranging from gene regulation to cell division. These processes are

critical to the survival of all living organisms. However, much is still unknown about

the principles and mechanisms that are responsible for organizing the genome. The

goal of this manuscript is to determine mechanisms that are responsible for

organizing the genome.

In mammalian cells, we provide evidence to show that a DNA repair protein,

γH2AX, is reproducibly deposited throughout the genome in undamaged cells. Our

data also suggest that γH2AX is preferentially found in silenced areas of the genome.

In budding yeast, we show that tDNAs have an effect on chromosome

structure. Our data indicate that tDNAs have a role in SMC protein binding,

centromere clustering, chromosome mobility, and gene silencing. Furthermore, these

effects seem to be mediated locally to the regions surrounding tDNAs.