Nuclear–cytoplasmic fractionation reveals small, yet significant discrepancies in nuclear and cytoplasmic mRNA editing levels. Mouse brain (n = 5) was isolated, homogenized, and subjected to nuclear–cytoplasmic fractionation. (A) Nuclear (Nuc.) and cytoplasmic (Cyt.) fractions were probed with antibodies against cytoplasmic GAPDH or nuclear histone H3 (Hist. H3). (B) Edited transcripts were amplified from nuclear or cytoplasmic RNA, and editing levels were determined using amplicon-seq. White bars indicate nuclear mRNA; black bars, cytoplasmic mRNA. (C) The ratio of pre-mRNA to mRNA (pre-mRNA–mRNA) editing was plotted against the ratio of nuclear to cytoplasmic (nuclear–cytoplasmic) mRNA editing.
