Figure 4

The three deletion mutants. (a-d,i,j) The predominant promoter activity for the indicated constructs, with (e-h,k,l) brightfield images as reference. (a) The arrow points to one of the strong clones, which is visible in many Q99JW1 wild-type (wt) fish compared to (b) the predominant deletion phenotype. (c) Similarly for the Q9BU67 native construct, the arrow in indicates an often found cluster of strong clones, which are hardly found in (d) the deletion construct injected fish. (i) SM31 shows ubiquitous expression found in most embryos injected with the native promoter, whereas (j) depicts the absence of green fluorescent protein expression with the deletion construct. These figures are representative examples from the large set of injections made for each construct (see Materials and methods). (m) Summary of the structure of the constructs used for reporter construction. Besides the native promoter, a construct was created with as precise a deletion of the motif as possible, together with a construct carrying a control deletion in a region presumably devoid of regulatory motifs.