Tom
Volpe, PhD
Assistant Professor
Department of Cell and Molecular Biology
To contact Dr. Volpe:
Tel (312) 503-5391
Fax (312) 503-7912
e-mail:t-volpe2@northwestern.edu
Dr. Volpe's website
Research Interests
Heterochromatin has been implicated in such diverse cellular processes
as dosage compensation, imprinting, stem cell function, chromosome segregation,
DNA repair and recombination. In addition, the role of heterochromatin in
regulation of epigenetic changes in gene expression (heritable changes in
gene expression that do not result from altered nucleotide sequence) has been
recognized in a very broad range of eukaryotic species including animals,
fungi and plants. The mechanisms by which cells establish and maintain heterochromatic
domains, however, are not fully understood.
We employ a strong genetic system, the fission yeast Schizosaccharomyces
pombe, as a model to study the regulation of heterochromatin in higher eukaryotes.
Our previous studies in S. pombe have shed new light on establishment and
maintenance of heterochromatic domains. We found that transcripts derived
from heterochromatic centromeric repeat sequences are processed by the RNA
interference (RNAi) machinery resulting in the sequence specific targeting
of heterochromatin formation to these sequences. Similar phenomena have been
observed in many eukaryotes including humans suggesting that RNA mediated
heterochromatin formation is conserved throughout evolution.
We use a combination of genetic, molecular, and cellular approaches to better
understand the mechanisms involved in RNAi dependent heterochromatin formation
in fission yeast. The information gained from our studies will provide insight
into the regulation of epigenetic phenomena in higher eukaryotes. This knowledge
may also be extremely useful for the development of methods to combat human
disease as well as strategies to study gene function.