Supplementary Figure 1: UBE3A isoform expression in mouse and human brain.

a. Mouse genomic structure of the Ube3a locus indicating the annotated splice variants relative to the longest isoform (Iso 2; NCBI Reference Sequence: NM_011668.3). ATG refers to the initiation codon in exon 3 (UBE3A iso2 protein) and to the initiation codon at the border of exons 4/5 (UBE3A iso3 protein). mUbe3a-Iso1 (NCBI Reference Sequence: NM_173010.3) is a non-coding transcript, but note that this RefSeq has been removed from the NCBI database because of insufficient support for this transcript. b. Quantification of hUBE3A-Iso3 and hUBE3A-Iso1 of three independent human post-mortem cortical (PFC) lysates. Inset shows a representative UBE3A immunoblot. The image is vertically stretched to separate the isoform bands for better quantiifcation. Data are shown as the mean +/- SEM. n=3 biologically independent samples. c. Quantification of mUbe3a-Iso1 RNA transcript in wild-type and isoform specific mutant mice. qPCR was performed on cDNA generated from total cortex RNA obtained from WT (n=3 mice), mUbe3a-Iso2^KO(n=2 mice) and mUbe3a-Iso3^KO (n=3 mice) mice, by using a reverse primer in exon 11b and exon 13, to determine the relative level of isoform 1 transcripts. The level of exon 10- exon 11a containing transcripts was set at 100%. The relative amount of transcripts containing exon 10-11a-11b was determined using the same forward primer in exon 10 and a reverse in Exon 11b. Note that the levels of mUbe3a-Iso1 are very low compared to total Ube3a mRNA. Data are shown as the mean +/- SEM. d. Full Western blot used for Supplementary Fig. 1b.