Fig. 5. Intron-removed mature Gomafu RNA is localized to the nuclear matrix. (A-A'') Localization of Gomafu RNA in the nucleus of E14 retinal cell detected with probes against exon (green, A') and intron (magenta, A'') sequences. Note that intron probes detected two foci (arrows), whereas exon probes detected a number of dots diffusely distributed throughout the nucleus. (B-E) Distribution of Gomafu RNA (green) and Sytox-stained DNA (magenta) in the control (B,C) and nuclear-matrix-extracted (D,E) cells. E14 retinal cells (B,C) or Neuro2A cells transfected with a Gomafu cDNA expression vector (D,E) were subjected to fluorescent in situ hybridization. Note that Gomafu RNA remained intact after nuclear matrix preparation. (F) Northern blot analysis of Gomafu RNA in the biochemical fractions. Gomafu RNA was highly insoluble and was mostly fractionated into the nuclear matrix. Bars, 2 µm.