<i>mec-8</i> and <i>exc-7</i> combines to regulate splicing of <i>unc-52</i> exons.

2017-11-09T19:01:14Z (GMT) by June H. Tan Andrew G. Fraser
<p>(A) <i>mec-8</i> and <i>exc-7</i> show antagonistic regulation of exons 17–18 in <i>unc-52</i> at the L1 stage. (B) Reduction of activity of both <i>mec-8</i> and <i>exc-7</i> show additive effects on <i>unc-52</i> splicing patterns at the L1 stage. (C) Study of <i>unc-52</i> splicing patterns <i>in vivo</i> using a bichromatic splicing reporter. The bichromatic splicing reporter was constructed using the same method as described by Norris <i>et al</i>. [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007033#pgen.1007033.ref048" target="_blank">48</a>]. Skipping of exons leads to expression of GFP, while inclusion of exon(s) results in a frameshift that leads to readthrough of the GFP reading frame, and resulting expression of mCherry. Worms were subjected to RNAi at the L4 stage, and late L1/L2 worms were imaged. A dsRNA that targets a <i>C</i>. <i>briggsae</i> gene was used as a non-targeting control. Transgenic <i>mec-8</i> mutant worms show increased inclusion of the <i>unc-52</i> minigene exons in hypodermal cells, while worms treated with <i>exc-7</i> RNAi show increased exon skipping. Transgenic <i>mec-8</i> worms treated with <i>exc-7</i> RNAi show both exon-included and exon-skipped isoforms in hypodermal cells. Examples of hypodermal cells that express both isoforms are highlighted with white arrowheads.</p>