Suzuki N et al. (1995) International C. elegans Meeting "ISOLATION OF DAUER-CONSTITUTIVE MUTANTS ON THE UNC-31 BACKGROUND"

Katsura I, Ishihara T, Suzuki N

[International C. elegans Meeting, 1995]

Many neural mutations that don't affect dauer formation by themselves (e.g. unc-31, unc-3 ) exhibit the dauer-constitutive (Daf-c) phenotype when they are combined to form double mutants[*]. We therefore isolated such synthetic Daf-c mutants on theunc-31 background to obtain new mutations that affect the nervous system. We screened 5539 F1 progenies derived from EMS-treated unc-31 worms and isolated 44 mutants that show the Daf-c phenotype on the unc-31 background but not by themselves. We mapped one of the mutations to linkage group (LG) I, 4 to LG II, 1 to LG III, 2 to LG IV, 6 to LG V and 13 to LG X, while the other 17 mutations have not been mapped. Since some known synthetic Daf-c mutations (e.g. osm-1 ) are defective in the uptake of fluorescein dye DiO into amphids and phasmids, we checked it for 42 of the 44 mutants. Thirty-four of them were normal in the uptake of DiO, while 6 of them were completely defective, and 2 of them showed incompletely penetrant defects. [*]WBG, Vol.13, No.2, P.36; Abstract by Katsura et al. this meeting

Suzuki N et al. (1997) International C. elegans Meeting "SYNTHETIC DAUER-CONSTITUTIVE MUTANTS ON THE unc-31 BACKGROUND"

Ishihara T, Katsura I, Suzuki N

[International C. elegans Meeting, 1997]

Many neural mutations exhibit dauer-constitutive (Daf-c) phenotypes when they are combined to form double-mutants, while they are Daf+ as single-mutants@. The unc-31(e169) mutation is one of such mutations having Synthetic abnormality in Dauer Formation (sdf): unc-31:unc-3 and unc-31:aex-3, for example, have Daf-c phenotypes$. Thus, we thought it is possible to discover new neural genes by isolating new Sdf-c mutations on the unc-31 background. We expected that mutations that impair the functions of ASI neurons are contained among them, because killing of ASI neurons in the unc-31 mutant is enough to make it Daf-c#. Forty-four mutants that exhibit Sdf-c phenotypes on unc-31background were isolated from 5539 of F1 Unc+ progeny of EMS-treated unc-31(e169);Ex[unc-31(+)]. We mapped 42 of them, of which eight were alleles of four known genes (1 allele of tax-2, 2 alleles of che-11, 2 alleles of osm-6 and 3 alleles of aex-3). The rest 34 mutations, which seem to map in new genes, were classified into 18 complementation groups. Some of the latter mutants have Osm phenotypes. Two mutants (sdf-3, sdf-12) have Dyf phenotypes. Interestingly, one mutant (sdf-1) avoids some AWC-sensed odorants that act as attractants to wild type worms. @WBG, Vol.13, No.2, P.36; 1995 meeting abstract by Katsura et al. $Bargmann, C.I. et al. CSHSQB 55, 529-538 (1990). #Avery, L. et al. Genetics 134, 455-464 (1993).

Suzuki N et al. (1993) International C. elegans Meeting "Cloning of manganese superoxide dismutase gene in C. elegans."

Suzuki N, Suzuki K, Ishii N

[International C. elegans Meeting, 1993]

K Nishiwaki et al. (1999) International C. elegans Meeting "MIG-17, an adam family metalloprotease required for dtc migration in C. elegans"

K Nishiwaki, N Suzuki, K Matsumoto, N Hisamoto

[International C. elegans Meeting, 1999]

The distal tip cells (DTCs) migrate on the body-wall basement membrane in a U-shaped pattern during gonadal development. They initially move along the ventral muscles, turn dorsally, and migrate on the lateral hypodermal cells. They turn again over the dorsal muscles and migrate along them. We have isolated mutants whose DTCs meander on the lateral hypodermal cells after the first turn. It is possible that the guidance cue for DTC migration or recognition of such a cue by DTCs is abnormal in these mutants. So far, eight genes have been identified by analyzing 20 isolated mutations. Many double mutant combinations displayed enhanced meandering phenotypes, suggesting that they affect the same or parallel pathways. Mutations in one of these genes mig-17 cause abnormal attachment of DTCs to the body wall. The DTCs migrate erratically on the body wall or are detached from it and migrate along the gonad or the intestine. We have cloned mig-17 and found that it encodes a novel member of the ADAM family metalloproteases. MIG-17 seems to have four distinct domains: following the signal peptide are a pro-domain, a metalloprotease domain, a disintegrin-like domain, and a cys-rich domain. The transmembrane domain conserved in conventional ADAMs was not detected in MIG-17, suggesting that it is secreted. A mig17::GFP fusion gene was functional and fully rescued a mig-17 null mutant. The GFP fluorescence was observed around the gonad and on the internal surfaces of the body wall muscles, consistent with localization of MIG-17 on the basement membranes. Deletion or point mutation analysis revealed that any of metalloprotease, disintegrin-like, or cys-rich domains are essential for the rescue of the mig-17 null mutant. The MIG-17 metalloprotease may function in the basement membranes to remodel their components, and this remodeling may ensure the attachment of DTCs to the body wall and their directional migration along the migration cue.

K Miyahara et al. (1999) International C. elegans Meeting "sdf-13/Ce-tbx-2 mutants have abnormality in odorant-specific adaptation."

T Ishihara, N Suzuki, K Miyahara, I Katsura

[International C. elegans Meeting, 1999]

We have isolated mutants in sdf (synthetic abnormality in dauer formation) genes, which convey a dauer-constitutive phenotype in unc-31 (e169) background (Sdf-c phenotype). At least 13 new genes are definrd by these mutations. Some of these mutants show abnormality also in chemotaxis, defecation, and adaptation. To investigate genes function at a molecular level, we are cloning genes for these mutations. Mutants (ut180, ut192) in one of the sdf mutants, sdf-13 , showed a high penetrance of Sdf-c phenotype. sdf-13 maps between dpy-17 and lon-1 on LGIII. We injected cosmid pools from this region in mutant animals and obtaine rescue. Further analysis showed that sdf-13 gene is identical with the Ce-tbx-2 gene which encodes a T-box protein (Agulnik at al.: Genomics 25: 214-219, 1995). SDF-13/CE-TBX-2 is a direct ortholog of Drosophila Omb and mouse TBX2, and is thought to function as a transcriptional factor. Mutations in sdf-13 gene caused defects in adaptation to some AWC-sesed odorants. After prolomged exposure to any one of these odorants, wild-type animals show decreased responsiveness to some of these odorants for several hours (odrant-adaptation), but sdf-13 amimals showed almost normaly chemotaxis even after such treatment. These data suggest that sdf-13/Ce-tbx-2 may play critical role in the control of odorant-adaptation through gene expression.

Martin Gutternigg et al. (2006) European Worm Meeting "Glycosidases of Caenorhabditis elegans involved in N-glycan processing"

Martin Gutternigg, Matthias Hackl, Ute Stemmer, Iain B. H. Wilson, Petra Geier, Gunter Lochnit, Ramona Ranftl, Katharina Paschinger, Verena Jantsch, Dorothea Lubich

[European Worm Meeting, 2006]

Martin Gutternigg, Dorothea Lubich, Matthias Hackl, Katharina Paschinger, Ute Stemmer, Verena Jantsch1, Gnter Lochnit2, Ramona Ranftl, Petra Geier and Iain B. H. Wilson. Recent data indicates that in addition to the Golgi ?-mannosidases, the model nematode Caenorhabditis elegans also possesses, like insects, an N-acetylhexosaminidase activity putatively involved in N-glycan processing in the Golgi. The presence of such an activity is invoked, not just on the basis of the detected enzyme activity, but also to explain the absence of terminal N-acetylglucosamine residues on structures which require the prior action of N-acetylglucosaminyltransferase I during their biosynthesis. In order to understand the genetic basis for these activities, we have cloned cDNAs encoding members of both glycohydrolase families 20 and 38 from the worm. The encoded glycosidases were expressed in the yeast Pichia pastoris as soluble forms lacking putative cytoplasmic and transmembrane domains. Four glycohydrolase family 20 members were shown to cleave p-nitrophenyl-?-N-acetylglucosaminide and/or p-nitrophenyl-?-N-acetylgalactosaminide, but showed contrasting specificities with regard to N-glycan substrates. On the other hand, one glycohydrolase family 38 member was shown to be active using p-nitrophenyl-?-mannoside as a substrate and, in addition, had mannosidase II activity. Analysis of the glycans of the relevant mutant showed large-scale changes in the N-glycosylation spectrum. These, therefore, are the first data on the activity of Caenorhabditis glycosidases towards N-glycan substrates and should aid the further elucidation of N-glycan processing in this organism.

Yamasaki, Akira et al. (2017) International Worm Meeting "Effects of Region-Specific Irradiation on Locomotion and Autophagy in C. elegans."

Zhang-Akiyama, Qiu-Mei, Suzuki, Michiyo, Kobayashi, Yasuhiko, Yamasaki, Akira, Funayama, Tomoo

[International Worm Meeting, 2017]

Ionizing radiation generates reactive oxygen species, and causes damage to cell components including DNA and protein. In C.elegans, radiation sensitivity is different from germline-cell and somatic cell. When adult C.elegans are irradiated with ten-fold higher dose than the dose that leads to germline-cell death, worms are still alive1. Locomotion using motor neurons and body-wall muscles was reduced immediately after irradiation with 0.5 kGy2. However the mechanism of reduction is not fully understood. In the present study, to investigate a tissue that is responsible for reduction of locomotion, we used region-specific microbeam irradiation. We used energetic carbon ions delivered from the AVF cyclotron at Takasaki Ion accelerators for Advanced Radiation Application facility of QST-Takasaki. After irradiation, a worm was replaced on NGM plate, and the locomotion was video-recorded and then the trajectory for 5-sec duration was derived by image processing of the movie. As a result, the same effects as whole-body irradiation were not observed after region-specific microbeam irradiation to pharynx or anterior half-body (the nerve ring, pharynx, intestine, and gonad) or posterior or posterior half-body (vulva, intestine, gonad, and tail). This suggests that the radiation effects on locomotion depend on the size of irradiation area. To detect the dose whether the reduction of locomotion is restored or leads to individual death, and we investigated alternation of locomotion after irradiation. We found the dose that locomotion of worms were completely stopped immediately after irradiation, and had been stopped at least twenty-four hours. Less than the dose, locomotion of the worms was reduced in a dose dependent manner, and was partially restored after twenty-four hours. Protein damage generated by irradiation may be involved in this reduction and restoration of locomotion, so we investigated whether autophagy is induced after irradiation. Using GFP reporter assay of lgg-1, one of the autophagosome genes, the increased level of GFP::LGG-1 was detected seven hours after irradiation in somatic cells. This suggests that autophagy may be one of the reasons of restoration of locomotion after irradiation. 1. Ishii,N., Suzuki, K., Int. J. Radiat. Biol., 58:827-833. (1990) 2. Suzuki, M., et al., J. Radiat. Res. 50, 119-125. (2009)

ZHANG, Gaotian et al. (2015) International Worm Meeting "Characterization of nematode-infecting microsporidia and natural variation in sensitivity of Caenorhabditis nematodes to microsporidia."

Zhang, Gaotian, Felix, Marie-Anne

[International Worm Meeting, 2015]

The microsporidian Nematocida parisii is the first characterized intracellular pathogen of Caenorhabditis elegans; and a second Nematocida species, called N. sp. 1, was also reported from an Indian C. briggsae isolate (Troemel et al. 2008). In our lab we further established a collection of wild rhabditid nematodes suspected with microsporidian infection. Here, we characterize molecularly these wild microsporidia and study their specificity of infection.First, the potentially infected rhabditid isolates were characterized using newly designed PCR primers specific for 18S and beta-tubulin genes of microsporidia. In addition to C. elegans, we found wild C. briggsae and Oscheius tipulae as natural hosts for N. parisii; in addition to C. briggsae, we found C. elegans and C. remanei as natural hosts of N. sp. 1. We further found three new microsporidian species. Two of them are close to the Nematocida species in microsporidian clade II and preliminarily named N.-like sp. 2 and N.-like sp. 3. The third species (or group of species), infecting Oscheius, is very distant, and found in microsporidian clade IV, that includes most human pathogens. They are closest to Orthosomella operophterae (with 18S), and thus preliminarily named Orthosomella-like spp.. Phylogenetic analyses with the 18S and beta-tubulin genes provide the same relationships of Nematocida spp. and the three putative new microsporidia species. Co-infections of two microsporidian species occurr in two wild O. tipulae strains, of which one infected with N. parisii and O.-like spp., the other infected with N. sp. 1 and O.-like spp. (confirmed by specific FISH probes).Secondly, two transgenic C. elegans strains ERT54 jyIs8[C17H1.6p::gfp; myo-2p::mCherry] and ERT72 jyIs15[F26F2.1p::gfp; myo-2::mCherry], which express a constitutive fluorescent Cherry marker and will induce GFP upon infection with N. parisii (Bakowski et al. 2014), were used in infection tests. Our results show that N. parisii, N. sp. 1, N.-like sp. 2 and N.-like sp. 3 can infect ERT54 and ERT72, forming meronts and spores; N. sp. 1 does not induce the GFP reporter (or only rarely), while the other three induce it consistently, suggesting that C. elegans has a different transcriptional response to the infection of N. sp. 1 than to other Nematocida spp. (see also abstract of Luallen et al.). The results also showed that O.-like spp. could not infect the two transgenic C. elegans strains (nor induce the GFP signals).

Jeon, JiHae et al. (2021) International Worm Meeting "N. parisii compensates for genomic loss of dihydroceramide desaturase through reliance on C. elegans sphingolipid biosynthesis"

Jeon, JiHae, Burton, Nick, Reinke, Aaron, Zhao, Winnie

[International Worm Meeting, 2021]

Microsporidia are obligate intracellular parasites that have lost many metabolic enzymes, resulting in the smallest known eukaryotic genomes. Microsporidia are highly dependant upon host nutrients, but it is poorly understood the effect that these parasites have on host metabolism. Using N. parisii, a natural microsporidian parasite of C. elegans, we describe how infection alters host lipid metabolism. We show that the C. elegans lipase ATGL-1 is upregulated in response to N. parisii infection and that host fat stores are depleted. Metabolic profiling of infected animals reveals large changes in lipid composition including changes consistent with nutrient starvation. Additionally, we identify novel ceramides only generated in animals infected with N. parisii. Genomic analysis reveled that N. parisii has lost the enzymes necessary for the de novo synthesis of these sphingolipids. Mutations in C. elegans dihydroceramide desaturases F33D4.4 and ttm-5 or acid ceramidase asah-2, reduce N. parisii growth. Supplementation with sphingosine, a substrate for ceramide synthesis, enhances N. parisii proliferation. Together, our data demonstrate that N. parisii exploits sphingolipid biosynthesis in C. elegans and reveals an evolutionary strategy used by microsporidian parasites to cope with extreme genomic reduction.

di Luccio, Eric et al. (2021) International Worm Meeting "N-NOSE is an innovative, non-invasive and highly sensitive cancer screening method based on the chemotaxis of C. elegans"

di Luccio, Eric, Hirotsu, Takaaki

[International Worm Meeting, 2021]

A simple, affordable, non-invasive, and highly sensitive cancer detection method is the Holy Grail in health screening. Especially early diagnosis of cancer is critical to increase the likelihood of recovery. N-NOSE (Nematode-NOSE) is a pioneering cancer screening method based on the chemotaxis of C. elegans which shows evasive behavior from the urine of healthy individuals while being attracted to the urine of cancer patients. N-NOSE has an average cancer-detection sensitivity of 86.3% in a clinical setting and detect the presence of cancer for 15 types at all stages: stomach, colorectal, lung, breast, uterine, liver, prostate, esophageal, ovarian, bile duct, gallbladder, bladder, kidney, pharyngeal, and pancreatic cancer. N-NOSE relies on a single drop of urine, is non-invasive and cheap, and is notably more sensitive than the blood tumor markers CEA, CA19-9 and CA15-3. In this presentation, we detail the C. elegans olfaction and chemotaxis method behind N-NOSE. Next, we review and summarize our recently published clinical studies on N-NOSE performed in several hospitals in Japan and compare N-NOSE performance to other cancer screening methods. Then, we briefly comment on the next generation of N-NOSE methods currently under development. Lastly, we outline our "World Consortium" R&D grant initiative to anyone in the world with the goal of contributing to the development of next generations of N-NOSE cancer-specific using nematodes. N-NOSE by Hirotsu Bio Science has been launched commercially in 2020 in Japan and is quickly seeking to expand overseas.