Figure 3

Verification of the differential expression of the cDNAs excised from the gels by mRNA in situ hybridisation of chick midbrain. (A-D) show the expression patterns of the mRNA coding for the transcripts isolated with the primer combinations indicated on the panels. Embryos were sectioned coronally, after whole mount in situ hybridisation at HH10. (E). Products of RT-PCR with gene-specific primers to verify differential expression of the transcripts in the dorsal and ventral parts of chick midbrains. Lanes are as follows: 1) HH 11 dorsal cDNA, 2) HH11 ventral cDNA, 3) HH16 dorsal cDNA, 4) HH16 ventral cDNA. The gene names and primer combinations are indicated above the relevant panels. GAPDH was used to normalize the cDNA expression levels. The equal amount of GAPDH amplified from ventral and dorsal midbrain cDNA demonstrates that there is no bias in the different cDNAs used.