Fig. 4

Activity of the trapping cassette in an exon of pSPL3-E3 vector.

pSPL3-E3 was generated by insertion of an exon from carp beta-actin gene (Exon3). The trapping cassette was then sucloned into the BamHI/EcoRI site of pSPL3-E3 vector to generate the pSPL3-E3/Trap(exon), which was used for transient transfection of HeLa cells at 80% confluence. Images were taken under a Nikon TE2000 fluorescent microscope at 48 h after transfection and cell numbers in three independent transfections were counted. Zebrafish embryos at one-cell stage were microinjected with the pSPL3-E3/Trap(exon). Injected embryos at 24 hpf were imaged under a SteReo Lumar V12 microscope form Zeiss and total embryos in three dishes were counted. The ectopic expression of EGFP in one embryo was enlarged and shown in a merged image. SD1, splice donor for exon1; SA3, splice acceptor for exon3; IR/DR(L) and IR/DR(R), left and right inverted repeat/directed repeat of the SB transposon; SA, splice acceptor; IRES, internal ribosome entry site; EGFP, enhanced green fluorescence protein gene; poly(A), poly(A) signal; SD3, splice donor for exon3; SA2, splice acceptor for exon2.