Photomicrographs of the expression of <i>twk-16</i> constructs in transgenic lines.

<p>The photomicrographs are arranged from left to right in three columns of six photomicrographs. <b>DVA expression of wild-type </b><b><i>twk-16</i></b><b> intron constructs.</b> Panels <b>A–F</b> are photomicrographs of the tail region of transgenic L4-adult <i>C. elegans</i> generated with the experimental sequences shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054971#pone-0054971-g005" target="_blank">Figure 5A</a>. Yellow lines indicate DVA neurons expressing YFP. The constructs used to generate the transgenics in each panel were: <b>A</b>. WT2000∶500 bp of the 5′region of <i>twk-16</i> gene, the first exon and entire 1.4-kb first intron with twk-16.cs1 and twk-16.cs2. <b>B</b>. WT500: twk-16.cs1 and flanking sequence producing both DVA and DVC expression. <b>C</b>. WT300: twk-16.cs1 and flanking sequence <b>D</b>. WT195: twk-16.cs1 and flanking sequence. <b>E</b>. WT113: twk-16.cs1 and flanking sequence. <b>F</b>. WT85: twk-16.cs1 and short flanking sequences. <b>Expression of wild-type </b><b><i>twk-16</i></b><b>.cs1 constructs.</b> Panels <b>G–L</b> are photomicrographs of the tail of transgenic L4-adult <i>C. elegans</i> animals with the following constructs: <b>G</b>. WT85∶53 bp of twk-16.cs1 with 17 bp 5′ and 12 bp 3′ of flanking sequence. <b>H</b>. WT53∶53-bp fragment of twk-16.cs1 in wild-type orientation. <b>I</b>. WT53R in reverse orientation (3′-5′) to the expression vector. <b>J</b>. WT29: the 5′ 29 bp of WT53. <b>K</b>. WT24: the 3′ 24 bp of WT53 <b>L</b>. Vector: no experimental sequence and PCR expression vector Δ<i>pes-10</i>::4X NLS::YFP::<i>unc-54</i>::<i>unc-119</i>. <b>Expression of mutated </b><b><i>twk-16</i></b><b>.cs1 constructs.</b> Panels <b>M–R</b> are photomicrographs of the tail region of transgenic L4-adult <i>C. elegans</i> animals made with the following constructs containing mutations (Mut2-Mut8) of the 53-bp fragment (WT53) of the twk-16.cs1 region: <b>M</b>. Mut5. <b>N</b>. Mut2. <b>O</b>. Mut2. <b>P</b>. Mut3. <b>Q</b>. Mut6. <b>R</b>. Mut8. L4 Vulva expression in Mut2 transgenic is shown in Panel O with a yellow line identifying the vulva. Scale bars are specific to each column of six photomicrographs and = 20 µm.