Nathan, Sara et al. (2015) International Worm Meeting "Identifying and characterizing odor receptors in C. elegans."

Cox-Harris, Alesha, Brueggemann, Chantal, Mosqueda, Berenice, Young, Jared, Newman, Elizabeth, Nathan, Sara, Morton, Riva, Dalton, Cassidy, L'Etoile, Noelle, Apostol, Sherrlyne

[International Worm Meeting, 2015]

Although scientists have been studying olfaction in C. elegans for decades, olfactory receptor proteins remain largely uncharacterized. To address this knowledge gap, we are pursuing localization of candidate odor receptor proteins, and studying odor responses in genetically altered worms. We are producing lines with GFP-tagged putative odor receptors using constructs obtain from the Transgeneome project, and looking for proteins that localize to sensory cilia. We are testing chemotaxis to a variety of odors of worms in which expression of putative odor receptors have been reduced using RNA interference. We are also generating knockout worms for putative odor receptors using the CRISPR technique, to be tested in chemotaxis assays. .

Sara Vassalli et al. (2006) European Worm Meeting "Identification of Genes required for Anchor Cell Attachment and Invasion during Vulval Development"

ALEX HAJNAL, Sara Vassalli

[European Worm Meeting, 2006]

Sara Vassalli and Alex Hajnal. During vulval development in the hermaphrodite, three out of six equivalent vulval precursor cells (the VPCs P3.p to P8.p) are induced by a signal from the gonadal anchor cell (AC). The LIN-3 EGF growth factor produced by the AC activates the EGFR/RAS/MAPK pathway in the VPCs to specify the primary cell fate. Prior to vulval induction, the gonad is separated from the VPCs by two basal laminas covering each tissue such that the position of the AC relative to the VPCs is variable when the animal moves. At the time of vulval induction in the early L3 stage, however, the AC attaches to the basal side of the future primary cell P6.p. After the first round of vulval cell divisions (Pn.px stage), the basal laminas separating the gonad from the vulval cells start to dissolve precisely under the AC. After the second round of divisions (Pn.pxx stage), the basal laminas between the AC and the four primary vulval cells are interrupted, and the AC invades the vulval tissue.. While the mechanism of vulval induction is well studied, less is known about genes regulating the attachment of the AC to P6.p and the following invasion step. To study these two processes, we performed a forward genetic screen for mutants with defects in AC positioning and/or invasion. Since worms with an abnormal or missing connection between the gonad and the vulva usually display a protruding vulva (Pvl) phenotype, we first screened for animals with a Pvl phenotype and then examined them for defects in the positioning or invasion of the AC. Among 5300 F1 clones, we identified 8 sterile mutants with a misplaced AC and 2 mutants, in which the AC is normally positioned but fails to dissolve the basal laminas and invade the vulval tissue. Details about the cloning and analysis of the genes identified in this screen will be presented at the meeting.