Development of <i>SMN2</i>-containing NIH3T3 cell lines with inducible knockdown of endogenous Smn.

<p>(A) Schematic representation of the exon-intron structure of the human <i>SMN2</i> gene used to establish NIH3T3-SMN2/Smn_RNAi cell lines (introns not drawn to scale). (B) Analysis of <i>SMN2</i> gene copy number in the indicated NIH3T3 cell lines by qPCR. Data were normalized to the <i>Gapdh</i> gene and expressed relative to the NIH3T3-SMN2_low/Smn_RNAi cell line. Data are represented as mean and SEM (n = 3; ** = p<0.01; t-test). (C) Analysis of total SMN2 mRNA levels in the indicated NIH3T3 cell lines by RT-qPCR. Data were normalized to Gapdh mRNA and expressed relative to the NIH3T3-SMN2_low/Smn_RNAi cell line. Data are represented as mean and SEM (n = 3; *** = p<0.001, t-test). (D) Analysis of SMN2 exon 7 splicing in the indicated NIH3T3 cell lines by radioactive RT-PCR. The levels of exon 7 inclusion are shown at the bottom.