GFP expression in transient zebrafish transgenic embryos obtained with constructs carrying pax6b and pax6a AB and/or C regions fused to the cfos heterologous promoter. (A) Restriction map of the zebrafish pax6b and pax6a genomic locus. The arrow indicates the transcriptional start site at the exon 0 (E0, marked in black). For the constructs, the different regions to test were fused to the cfos heterologous promoter. The arrow indicates the transcriptional start site at the cfos. Fusion constructs (AB-cfos and C-cfos) were made by PCR using specific primers (see materials and methods for sequences). These DNA constructs were injected into zebrafish embryos using Tol2 mediated transgenesis and GFP transient expression was analysed at 24, 48 and 75 hours of development. (B) Transient GFP expression in 75 and 48 hpf embryos injected with the full ABC-cfos and the C-cfos constructs. All the embryos are presented in dorsal views with anterior on the left. Abbreviations: p, pancreas.