The expression of genes is strongly influenced by their position within the genome.  Genes can become permanently repressed when placed near centromeres, telomeres or other regulatory elements, a phenomenon referred to as position-effect variegation
or gene silencing. 

We are using the budding yeast Saccharomyces cerevisiae to study how silenced genomic loci are assembled into repressive chromatin and how histone and protein acetylation influence this process.