Figure 2.

RT-PCR analysis of alternative exons 4, 5 and 15 of zebrafish tcf7l2 across development and in various adult organs. (A) Schematic representation of nested RT-PCR strategy used for panels B, C, F and G. (B–C) cDNA from embryos of ages indicated (hpf) was PCR amplified using a forward primer that anneals over exon 4 (B) or exon 5 (C) and a reverse primer that anneals to exon 16 common to all tcf7l2 mRNA variants. The product from this first PCR was then used as a template for a nested PCR using primer set ‘b’ (as in Figure 1. A) that amplifies exon 15 and reveals the different possible Ct ends of Tcf7l2. This last PCR product is shown in these panels. M (Medium), S (short) and L (Long) C-terminal Tcf7l2 variant end. (D–E) RT-PCR experiments performed on cDNA of the indicated adult organs using primer set ‘a’ (Materials and methods) amplifying the region of alternative exons 4 and 5 (D) or using primer set ‘b’ (Materials and methods) amplifying the region of alternative exon 15 (E). (F–G) Same PCR amplification strategy used in panels (B–C) to detect the C-terminal Tcf7l2 variants associated with exons 4 or 5, but using the indicated adult organ cDNA as template in the 1^st PCR reaction.