Spatial expression patterns generated by the individual segments a–f fused to the GFP cassette.

<p><b>A</b>: Graphical positioning of the upstream <i>PlCoup-TF</i> segments (a–f) within the 1932 bp upstream sequence, which were individually fused to the <i>EpGFPII</i> reference gene. The numbers surrounding each black bar correspond to the nucleotide borders of each segment. Other designations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109274#pone-0109274-g004" target="_blank">Figure 4A</a>. <b>B</b>: Composite pictures of embryos resulting from injection of segments a–c. Segment a results in GFP expression specifically in the ciliary band, while segments b and c show GFP expression in the ciliary band, endoderm and mesenchyme cells. All embryos were photographed at pluteus stage. Embryos injected with segments d, e and f did not exhibit GFP expression.