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The association of Brahma with the Balbiani ring 1 gene of Chironomus tentans studied by immunoelectron microscopy and chromatin immunoprecipitation
Author(s) -
Botelho S. Calado,
Tyagi A.,
Hessle V.,
Östlund Farrants A. K.,
Visa N.
Publication year - 2008
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1111/j.1365-2583.2008.00825.x
Subject(s) - chromatin immunoprecipitation , biology , chromatin , gene , immunoelectron microscopy , promoter , gene expression , transcription factor , transcription (linguistics) , chia pet , microbiology and biotechnology , chromatin remodeling , genetics , computational biology , antibody , linguistics , philosophy
Many steps of gene expression take place during transcription, and important functional information can thus be obtained by determining the distribution of specific factors along a transcribed gene. The Balbiani ring (BR) genes of the dipteran Chironomus tentans constitute a unique system for mapping the association of specific factors along a eukaryotic gene using immuno‐electron microscopy (immuno‐EM). The chromatin immunoprecipitation (ChIP) technique has provided an alternative, more general method for studying the association of proteins with specific genomic sequences. The immuno‐EM and the ChIP methods suffer from different limitations, and thus a combination of both is advantageous. We have established optimal conditions for ChIP on chromatin extracted from the salivary glands of C. tentans , and we have analyzed the association of the SWI/SNF chromatin remodelling factor Brahma (Brm) with the BR1 gene by combined immuno‐EM and ChIP. We show that Brm is not restricted to the promoter of the BR1 gene but is also associated with sequences in the middle and distal portions of the gene, which suggests that Brm has additional roles apart from regulating transcription initiation.