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Chromatin is composed of DNA and a variety of modified histones and non-histone proteins, which have an impact on cell differentiation, gene regulation and other key cellular processes. Here we present a genome-wide chromatin landscape for Drosophila melanogaster based on eighteen histone modifications, summarized by nine prevalent combinatorial patterns.(More)
Genes normally resident in euchromatic domains are silenced when packaged into heterochromatin, as exemplified in Drosophila melanogaster by position effect variegation (PEV). Loss-of-function mutations resulting in suppression of PEV have identified critical components of heterochromatin, including proteins HP1, HP2, and histone H3 lysine 9(More)
We report here that a point mutation in the gene which encodes the heterochromatin-specific nonhistone chromosomal protein HP-1 in Drosophila melanogaster is associated with dominant suppression of position-effect variegation. The mutation, a G-to-A transition at the first nucleotide of the last intron, causes missplicing of the HP-1 mRNA. This suggests(More)
Significant portions of the eukaryotic genome are heterochromatic, made up largely of repetitious sequences and possessing a distinctive chromatin structure associated with gene silencing. New insights into the form of packaging, the associated histone modifications, and the associated nonhistone chromosomal proteins of heterochromatin have suggested a(More)
A euchromatic gene placed in the vicinity of heterochromatin by a chromosomal rearrangement generally exhibits position effect variegation (PEV), a clonally inherited pattern showing gene expression in some somatic cells but not in others. The mechanism responsible for this loss of gene expression is investigated here using fly lines carrying a P element(More)
Monoclonal antibodies were prepared against a fraction of nuclear proteins of Drosophila melanogaster identified as tightly binding to DNA. Four of these antibodies were directed against a 19-kilodalton nuclear protein; immunofluorescence staining of the polytene chromosomes localized the antigen to the alpha, beta, and intercalary heterochromatic regions.(More)
The heterochromatic domains of Drosophila melanogaster (pericentric heterochromatin, telomeres, and the fourth chromosome) are characterized by histone hypoacetylation, high levels of histone H3 methylated on lysine 9 (H3-mK9), and association with heterochromatin protein 1 (HP1). While the specific interaction of HP1 with both H3-mK9 and histone(More)
To gain insight into how genomic information is translated into cellular and developmental programs, the Drosophila model organism Encyclopedia of DNA Elements (modENCODE) project is comprehensively mapping transcripts, histone modifications, chromosomal proteins, transcription factors, replication proteins and intermediates, and nucleosome properties(More)
The interface between cellular systems involving small noncoding RNAs and epigenetic change remains largely unexplored in metazoans. RNA-induced silencing systems have the potential to target particular regions of the genome for epigenetic change by locating specific sequences and recruiting chromatin modifiers. Noting that several genes encoding RNA(More)
Eukaryotic genomes are packaged in two basic forms, euchromatin and heterochromatin. We have examined the composition and organization of Drosophila melanogaster heterochromatin in different cell types using ChIP-array analysis of histone modifications and chromosomal proteins. As anticipated, the pericentric heterochromatin and chromosome 4 are on average(More)