Figure 2.

six3a promoter deletion mutant constructs. I. Different deletion constructs used to study the combinatory effect of those modules. The names of those constructs are given by the length of each DNA fragments ligated to Bp. Followed each construct are the summary of the GFP expression level after microinjection into zebrafish embryos. Zebrafish embryos injected with each construct expressing GFP at different times (8, 11 and 24 hpf) and regions (eyes, forebrain and ectopic) are labeled "+", "++" and "+++" to indicate different levels of GFP intensity. The symbol "-" indicates the absence of GFP expression. II. The percentages of embryos expressing GFP from different batches are shown in the bar graph. The total numbers of embryos are indicated as N=number above each bar. Three different time points were shown: 8 hpf (orange), 11 hpf (blue) and 24 hpf (red). III. Representative GFP expression patterns for each construct. (A) 3087-Bp-GFP shows accurate and strong GFP expression in the forebrain and eyes. (B) 1562-Bp-GFP shows a similar expression pattern to 3087-Bp, with minor ectopic expression on the ventral side. (C) 1060-Bp-GFP shows similar expression and strong ectopic expression on the ventral side. (D) 898-Bp-GFP shows weak expression in the eyes and forebrain. (E) 749-Bp-GFP shows GFP expression in the eyes. (F) 681-Bp-GFP has GFP expression extending to the eye. (G) 448-Bp has very weak GFP expression in the eyes. (H) Bp-GFP, as a control, shows almost no expression of GFP, except for 1-2 cells in the forebrain region.