Developmental stage-dependent expression of the zebrafish SULT3 ST1 and SULT3 ST2. (A) RT-PCR analysis of the expression of mRNAs encoding SULT3 ST1 and SULT3 ST2 at different stages during embryogenesis and larval development onto maturity. Final PCR mixtures were subjected to 0.9% agarose electrophoresis. Samples analyzed correspond to unfertilized zebrafish eggs, zebrafish embryos during the zygote period (0-h post-fertilization (pf), cleavage period (1-h pf), blastula period (3-h pf), gastrula period (6-h pf), neurula/segmentaion period (12-h pf), pharyngula period (24-h pf), and hatching period (48- and 72-h pf), 1-, 2-, 3-, 4-week-old zebrafish larvae, and 3-month-old adult male or female zebrafish. The positions of PCR products corresponding to different zebrafish SULT3 ST1 or SULT3 ST2 cDNAs, visualized by ethidium bromide staining, are marked by arrows. (B) RT-PCR analysis of the expression of the zebrafish β-actin at the same developmental stages as those described in (A). The figure is illustrative of three independent repetitions with different samples.