Exploiting Polytene Chromosomes to Identify Transcription Cofactors and Complexes Recruited to an Estrogen Responsive Promoter In Vivo
Abstract
The purpose of this work was to develop a novel system to study the recruitment of factors, especially those involved in chromatin modification and remodeling, to an estrogen-responsive promoter. To do this, transgenic fruitflies were created that conditionally express estrogen receptors and that contain a reporter whose expression is dependent on the estrogen receptor. Six doubly transgenic lines were developed. These transgenic flies were shown to express the estrogen receptor in response to heat shock and the reporter (green fluorescent protein) in response to estrogens. For two of the lines thus far, estrogen-dependent expression of the reporter in salivary glands has been confirmed. We have also shown that estrogen receptor moves from regions of the nucleus not occupied by chromatin to chromatin upon activation of the estrogen receptor by hormone agonists. We are now preparing to assess hormone- dependent recruitment of factors to the target locus by fluorescence immunohistochemistry of chromosome squashes. In this way we will be able to assemble a detailed picture of the functional complexes that mediate estrogen action and delineate the time course of their formation. In particular, this will lead to a better understanding of the role of chromatin remodeling and modification in estrogen action.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2002
- Accession Number
- ADA405578
Entities
People
- Steven K. Nordeen
Organizations
- University of Colorado Health