Dr. Potok [HHMI Fellow] is investigating how gene expression is controlled by heterochromatin (the physically compacted form of DNA) and genomic instability. In the plant Arabidopsis thaliana, reduction in a chemical mark on the chromatin, called H3K27me1, results in heterochromatin decompaction, abnormal gene expression and the production of extra DNA from certain regions. Extra copies of DNA are a sign of genomic instability often observed in cancers. She will characterize the mechanism underlying genomic instability. The results of this study may add insight into the connection between epigenetic gene silencing, nuclear architecture, and genome stability, leading to an understanding of why they are misregulated in cancer.