TFIIIC controls activity-dependent relocation of neuronal genes.

<p>Two days after plating, mouse primary cortical neurons were transfected with control or Gtf3c5 siRNA in combination with an eGFP-actin expression vector. After three days, neurons were stimulated with 50 mM KCl for 45 minutes or left untreated and analysed by immuno-DNA FISH targeting <i>c-Fos</i>, <i>Gadd45b</i> and <i>Csn2</i> loci. (A) Representative images of single confocal sections of immuno-DNA FISH experiments showing the nuclear localization of <i>c-Fos</i> and <i>Gadd45b</i> loci (green) relative to TFs, detected by RNAPII-ser5P immunostaining (red). GFP staining was confined outside the nuclear space (stained with DAPI, blue) and did not interfere with the FISH signal. For each image series, the distance between the centre of the FISH signal and the nearest TF is indicated (top right inset). Scale bars, 2 µm (images on the left) and 0.5 µm (magnified images). (B) Percentage of co-localization with TFs of <i>c-Fos</i>, <i>Gadd45b</i> and <i>Csn2</i> gene loci both in basal conditions an in response to KCl in neurons transfected with either control or Gtf3c5 siRNA (*, P<0.05, Fisher's exact test; n = 32 to 44 FISH signals per condition).