Figure 4

Specificity of the Sepn1 probes. A: Schematic representation of the murine (Sepn1) and human (SEPN1) mRNA. Exons and the SECIS sequence are represented by grey and black boxes, respectively. The human third exon, corresponding to an Alu sequence, is represented by a white box. Target sequences of Pr1 and Pr2 ISH probes are shown above the schema. B: Northern blot analysis, using the Pr1 probe, of RNA extracted from human control fibroblasts (c) and fibroblasts from a RSMD1 patient with a homozygous premature stop codon, leading to SEPN1 mRNA degradation (p). β-actin is used as a reference. A 4.2/4.3 kb band was observed in control fibroblasts but not in RSMD1 fibroblasts, validating the specificity of Pr1 for SEPN1 transcripts. C: Northern blot analysis of RNA from mouse E12 (mE12) and E18 (mE18) whole embryos shows a single 3.4 kb band corresponding to Sepn1 transcript.