A temperature sensitive missense mutation in <i>pigv-1(qm34)</i> leads to defects in embryonic elongation.

<p>(A) Wild type L1 larva (left panel), and <i>pigv-1</i>(<i>qm34</i>) (right panel) exhibiting a morphological defect close to the head. (B) Gene and protein organization of PIGV-1. <i>qm34</i> is a <i>pigv-1</i> allele with a missense mutation at the amino acid 361 converting glycine to glutamic acid (indicated by a star). E denotes exon and TM denotes transmembrane. Light gray box after exon 8 indicates the 3’UTR. (C) <i>pigv-1</i>(<i>qm34</i>) embryos are heat-sensitive; Percent of wild type and <i>pigv-1</i>(<i>qm34</i>) embryos that fail to hatch at 15^°C, 20^°C, and 25^°C. (D) Wild type embryo progressively elongates from 2 folds to almost 4 folds in an hour (upper panel), whereas <i>pigv-1</i>(<i>qm34</i>) embryo arrested during elongation at 3 fold stage (lower panel) with a rupture (stippled orange line) and cysts formed in excretory canal (red arrow) and intestine (blue arrow). In all images, anterior is to the left, time stamp is in minutes. (E) Classification of the terminal phenotypes of wild type and <i>pigv-1</i>(<i>qm34</i>) embryos based on 4D Nomarski movies, as shown in D. (F) In the upshift experiments, <i>pigv-1</i>(<i>qm34</i>) embryos at different embryonic stages dissected from gravid adults grown at 15^°C were upshifted to 25^°C and maintained at the restrictive temperature throughout embryogenesis and scored as lethal when they did not hatch at the end of embryogenesis. For downshift experiments, similar procedure was done except that worms were kept at 25^°C for 24 hours before downshifted to 15^°C. FC denotes founder cells generation, G denotes gastrulation, VCC denotes ventral cleft closure, DI denotes dorsal intercalation, VE denotes ventral enclosure, EE denotes early elongation and LE denotes late elongation. (G) WRM0638cC08 fosmid containing <i>pigv-1</i> and GFP::PIGV-1 expression driven by <i>erm-1</i> promoter significantly rescues <i>pigv-1</i>(<i>qm34</i>) embryonic lethality. Data in C and G are presented as average ± s.e.m. For each experiment, more than 100 embryos were counted. Experiments were done in duplicate and repeated five times (*<i>P</i> <0.05, **<i>P</i><0.01, two-tailed test). See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005082#pgen.1005082.s012" target="_blank">S1</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005082#pgen.1005082.s013" target="_blank">S2</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005082#pgen.1005082.s014" target="_blank">S3</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005082#pgen.1005082.s015" target="_blank">S4</a> Tables for numerical values and statistical analyses of data presented in panel C, E, F and G, respectively.