Chromosome conformation capture on chip (4C) at the Fab7 polycomb response element in the bithorax complex of Drosophila

ABSTRACT: In Drosophila melanogaster, Hox genes are organized in an anterior and a posterior cluster, called Antennapedia complex and bithorax complex, located on the same chromosome arm and separated by 10 Mb of DNA. Both clusters are repressed by Polycomb group (PcG) proteins. Here, we show that genes of the two Hox complexes can interact within PcG bodies in the cell nucleus in tissues where they are corepressed. This colocalization increases during development and depends on PcG proteins. Hox gene contacts are part of a large gene interaction network that includes other PcG target genes. Moreover, they are conserved in the distantly related Drosophila virilis species, and mutations on one of the loci weaken silencing of genes in the other locus, resulting in the exacerbation of homeotic phenotypes in a sensitized genetic background. Thus, the three-dimensional organization of Polycomb target genes in the cell nucleus is an evolutionarily conserved phenomenon that stabilizes the maintenance of epigenetic gene silencing. Chromosome Conformation Capture on Chip (4C) was used to establish chromosomal interactions involving the Fab7 polycomb response element from the bithorax complex of Drosophila melanogaster. Larval brain and anterior discs from 3rd instar larvae were dissected to produce 2 replicate experiments with wild-type (WT-r1, WT-r2) and Fab-712 (F12-r1, F12-r2) fly lines. The 3C was performed as previously described (Hagege et al., 2007; Miele and Dekker, 2009) with the main differences being the use of DpnII (New England Biolabs), a 4 bp cutter restriction enzyme, and a fixation in 3% para-formaldehyde for 30 min, maximizing sensitivity and resolution of contact detection. The 4C DNA and DpnII digested genomic DNA (Control) samples were hybridized using a tiling array mapping the whole chromosome 3R which includes the antenapedia and bithorax hox clusters.

ORGANISM(S): Drosophila melanogaster

SUBMITTER: Giacomo Cavalli 

PROVIDER: E-GEOD-23887 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress