Generation and characterization of stable C/ebpαDN transgenic lines with Cre-loxp strategy. (A-C) Schematic representations of transgenic lines Tg(lmo2:Cre) (A), Tg(lmo2:LDL-EGFP) (B), and Tg(lmo2:LDL-EGFP-C/ebpαDN) (C). All transgenes were under the control of a 2.5-kb lmo2 promoter. The EGFP or EGFP-tagged C/ebpαDN gene was separated from the lmo2 promoter by loxp-DsRed-loxp (LDL) element. Truncated zebrafish C/ebpαDN was in-frame fused with EGFP. Arrows at the bottom of panel C indicate the position of primers used in genomic PCR for genotyping. pA indicates SV40 polyadenylation site. (D-G) Representative 22 hpf progeny of mating Tg(lmo2:LDL-EGFP) with either wild-type (D) or Tg(lmo2: Cre) heterozygote (E), and mating Tg(lmo2:LDL-EGFP-C/ebpαDN) with either wild-type (F) or Tg(lmo2:Cre) heterozygote (G). Red-green fluorescence shifts can only be detected in the double-transgenic embryos carrying the Cre recombinase gene (E,G). The stars indicate the residual red fluorescence after Cre-mediated genomic recombination. HV indicates head vasculature. (H) Western blot analyses confirmed the expression of EGFP (27 kDa) and EGFP-tagged C/ebpαDN fusion protein (54 kDa) in the transgenic embryos presented in panels D to G corresponding to lines D′ to G′.