FIG. 4.

Temporal resolution of GFP expression. Zebrafish embryos were electroporated at 24 hpf. (A) The percentage of embryos expressing GFP was determined at various times after electroporation. Embryos were considered positive if at least 10 cells with neuronal morphology were expressing GFP; however, the vast majority of positive embryos had 100-plus cells showing fluorescence. Data points connected by a line are from the same group of embryos followed over time. Each point represents the percentage expression for 6–15 embryos. Data points are color-coded to investigator (blue: S.A.; red: S.K.). Data points connected by a line (and having the same symbol) are from the same group of embryos followed over time. (B, D, F) Embryos electroporated at 24 hpf displayed significant GFP expression at 6 h after electroporation. (C, E, G) Embryos electroporated at 48 hpf also displayed significant GFP expression at 6 h after electroporation. White boxes in the combined fluorescent/bright-field images in (B) and (C) represent the area of the higher magnification fluorescent images shown in (D) and (E), respectively. (F, G) Coelectroporation of a GFP expression plasmid and an mCherry expression plasmid resulted in coexpression of GFP (F) and mCherry (G) 6 h after electroporation. Scale bars equal 100 μm (B, C) and 25 μm (F, G).