Fig. 5.

FoxA1 is a regulator of SSC development. (A) The foxa1 gene has two exons and one intron. An antisense morpholino oligo (red) was designed against the splice junction of exon 1 and intron 1. Loss of foxa1 transcript is evident with foxa1 MO compared with controls (MOC) by RT-PCR (using primers either side of the splice site), indicating knockdown of expression. A higher band was evident for the foxa1 morphants, which is indicative of an unspliced transcript. There is no difference in the intensity of bands for the ubiquitously expressed gene ornithine decarboxylase (ODC). (B) Representative images of stage 32 embryos showing the frequency of each cell type after applying MOC or foxa1 morpholino. Ciliated cells were marked by α-1-tubulin, SSCs by itpkb, ionocytes by atp6v1a and goblet cells by antibody to Xeel. The total number of cells in a defined area was determined by DAPI staining of nuclei and a ratio for each marker relative to the total number of cells was determined as shown in the chart. The mean ratio for ten embryos is shown for each sample. Error bars represent s.e.m. Student’s t-test, P<0.01 (^**). Scale bars: 50 μm.