Gene function in eukaryotes is dependent on the interaction of chromatin structure and DNA sequence-specific factors. The Polycomb repressor is a key chromatin-dependent regulator of developmental genes and cell differentiation in metazoans. As cell fates are determined, Polycomb repression is activated at specific DNA regulatory elements and expands across large chromatin domains. While many of these regulatory elements have been mapped, but what factors nucleate repression in some cell types, and how this spreads remains mysterious. My laboratory has developed novel methods to detect all occupied binding sites in a genome, based on the release of native protein-DNA particles by nuclease digestion. In this proposal, we use these methods to analyze the structure and composition of regulatory elements in different cell types in Drosophila, a model organism where Polycomb repression is best characterized. We will systematically analyze embryonic mesoderm to provide a comprehensive picture of the changes in regulatory elements and chromatin during development.

Public Health Relevance

Gene function in eukaryotes is dependent on the interaction of chromatin structure and DNA sequence-specific factors. Our project will use a new method - MNase-Seq - to determine the landscape of non-histone proteins in chromatin. We focus on defining the factor complexes that occupy regulatory elements for Polycomb-mediated chromatin repression, and explore the epigenetic mechanisms that modulate repression during cell differentiation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM108699-03
Application #
9098750
Study Section
Molecular Genetics B Study Section (MGB)
Program Officer
Carter, Anthony D
Project Start
2014-09-01
Project End
2018-05-31
Budget Start
2016-06-01
Budget End
2017-05-31
Support Year
3
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
078200995
City
Seattle
State
WA
Country
United States
Zip Code
98109
Kasinathan, Bhavatharini; Ahmad, Kami; Malik, Harmit S (2017) Waddington Redux: De Novo Mutations Underlie the Genetic Assimilation of Stress-Induced Phenocopies in Drosophila melanogaster. Genetics 207:49-51
Orsi, Guillermo A; Kasinathan, Sivakanthan; Zentner, Gabriel E et al. (2015) Mapping regulatory factors by immunoprecipitation from native chromatin. Curr Protoc Mol Biol 110:21.31.1-25