FIGURE 1.

Generation and expression pattern of araf-tv2 variant. A, schematic diagrams of araf expression products. The zebrafish araf locus consists of 15 exons (1–15). The transcription would halt at the alternative polyadenylation (pA) sites, ultimately generating araf-tv1 and araf-tv2. The 84-bp coding sequence specific for araf-tv2 was shown in red letters. The boxes in transcripts represented untranslated regions. The arrowheads indicated primers used. B, amplification of araf-tv2 transcript. For the 1st round (R1) and 2nd round (R2) RT-PCR, P1/pT₁₅VV, and p2/p5 primer pairs were used, respectively. The product in R2 was confirmed by sequencing. M, molecular markers. C, relative amounts of araf-tv1 and araf-tv2 transcripts in embryos at different stages. The p1/p3 primers for araf-tv1 and p4/p5 primers for araf-tv2 were mixed for amplifying both transcripts in the same reaction tube by semi-quantitative RT-PCR. β-actin was used as the internal control. The bands resolved in the gel were quantified by Image J software. D, expression pattern of araf-tv2 in zebrafish embryos were detected by whole mount in situ hybridization.