Figure 3.

p97FE65 mice express alternative isoform of FE65 in the developing pit. A, Schematic illustrating products used to differentiate between p97 and p60 isoforms of FE65. The p97 isoform of FE65 originates from a start codon in exon 2. The truncated p60FE65 form originates from an alternative start codon in exon 3. Different regions of FE65 analyzed by RT-PCR are represented in red (EX-2, EX7–10, EX13–14) together with the expected length. B, C, Phase-contrast picture of VNO (indicated with red dashed line) before (B) and after (C) laser capture microdissection. D, E, PCR products obtained from cDNA of laser captured cortex and VNO from WT (D) and p97FE65 embryos. In the mutant material, no amplification of exon 2 was found, but bands were detected for exons 7–10 and 13–14, indicating expression of the alternative forms of FE65. F–H, Double immunofluorescence for FE65 (red) and pan-neuronal marker Hu (green) in WT (F), p97FE65 KO (G), and p97/60FE65 KO (H) E14.5 sections through the VNO. FE65 expression was found in newly formed neurons (arrowheads) in WT (F) and p97FE65 KO (G), whereas only background staining was observed in p97/60FE65 KO (H).