Splicing of a subset of minor introns containing suboptimal BPS is not affected in spinal cords of SMA mice. RT-PCR analysis of minor introns splicing efficiency in spinal cords of control (WT6, WT7) and SMA (KO6, KO9, KO10) mice. Gene names and size (in base pairs) of the amplified products are indicated on the left. The schematic structure of the amplified products is shown on the right. The branchpoint sequence aligned with the anti-branch site of the U12 snRNA (in italics) as well as the U12 BPS scores are shown on the right. The putative branch site adenosine is indicated in bold. Minor introns with low BPS scores are retained (A) or not affected (B) in spinal cords of SMA mice. (C) Retention index of minor introns in spinal cords of control (WT, n = 2) and SMA (SMA, n = 3) mice determined as described in the Materials and Methods section. Mean and SEM are shown. Statistical significance was calculated using the Student t-test (ns: nonsignificant; (*) P < 0.05; (**) P < 0.01). Histograms for Gosr1 are not shown because retained intron is not detectable.
