Vancoppenolle B et al. (1996) European Worm Meeting "Comparison of the early embryonic cell lineage of Caenorhabdi- tis elegans and Pellioditis marina, two rhabditid nematodes."

Vancoppenolle B, Coomans AV, Schnabel R, Borgonie G

[European Worm Meeting, 1996]

The early embryonic cell lineage of Pellioditis marina, a marine rhabditid with relatively short developing time was traced using a 4D-microscope. Although the general pattern of cell divisions is congruent with the lineage described for Caenorhabditis elegans by Sulston and coworkers, striking differences can be observed concerning migrations, timing of divisions and cell deaths. The AB, MS and C lineage of P. marina differ from those of C. elegans both in the occurence of additional cell deaths as wel as in the abscence of certain cell deaths. Additionaly, Caap does not divide in accordance with the characteristic period of the rest of the C lineage. In contrast with C. elegans, the E founder cell in P. marina undergoes a migration before gastrulation and devides into Ea and Ep only after E has entered the interior of the embryo. D and P4 divide in a similar way as in C. elegans.

Vancoppenolle B et al. (1997) International C. elegans Meeting "COMPARISON OF THE EMBRYONIC CELL LINEAGE OF CAENORHABDITIS ELEGANS AND PELLIODITIS MARINA"

Borgonie G, Vancoppenolle B, Schnabel R, Coomans AV

[International C. elegans Meeting, 1997]

The early embryonic cell lineage of Pellioditis marina, a marine rhabditid with relatively short developing time (9hrs at 25!C) was traced using a 4D-microscope. Although the general pattern of cell division is congruent with the lineage described for Caenorhabditis elegans by Sulston and Co-workers, striking differences can be observed concerning migrations, timing of divisions and cell deaths. The AB, MS and C lineage of Pellioditis marina differ from those of Caenorhabditis elegans both in the occurence of additional cell deaths as well as in the abscence of certain cell deaths. Additionaly, Caap does not divide in accordance with the characteristic period for the rest of the C-lineage. In contrast with Caenorhabditis elegans, the E founder cell in Pellioditis marina undergoes a migration before gastrulation and divides into Ea and Ep only after E has entered the interior of the embryo. D and P4 divide in a similar way as in Caenorhabditis elegans.

Kuroyanagi, Hidehito et al. (2021) International Worm Meeting "Alternative splicing through m6A modification at a 3' splice site for SAM synthetase homeostasis"

Togo-Ohno, Marina, Fukamizu, Akiyoshi, Watabe, Eichi, KUROYANAGI, Hidehito, Hirota, Keiko, Ishigami, Yuma, Suzuki, Tsutomu, Suzuki, Yutaka

[International Worm Meeting, 2021]

Alternative splicing of precursor messenger RNAs (pre-mRNAs) contributes not only to proteome diversity but also to regulation of gene expression levels by generating mRNA isoforms with a premature termination codon (PTC). Such unproductively spliced mRNAs are unstable and almost undetectable due to an mRNA surveillance system termed nonsense-mediated mRNA decay (NMD). In order to elucidate a repertoire of mRNAs regulated by alternative splicing coupled with NMD (AS-NMD), we performed long-read RNA sequencing of poly(A)+ RNAs from an NMD-deficient mutant, smg-2, and obtained full-length sequences for mRNA isoforms from 259 high-confidence AS-NMD genes. Gene ontology (GO) analysis revealed enrichment of genes related to metabolism in addition to those related to RNA translation and processing. Among them are S-adenosyl-L-methionine (SAM) synthetase (sams) genes. SAM synthetase activity negatively autoregulates sams gene expression through AS-NMD. METT-10, the orthologue of human U6 snRNA methyltransferase METTL16, is required for the splicing regulation of the sams genes in vivo and specifically methylates in vitro the invariant AG dinucleotide at the distal 3' splice site (3'SS) used for the productive mRNAs. RNA immunoprecipitation with anti-m6A antibody and direct RNA sequencing with Nanopore technologies coupled with machine learning confirmed m6A modification of endogenous sams mRNAs. These results indicate that homeostasis of SAM synthetase in C. elegans is maintained by alternative splicing regulation through m6A modification at the 3'SS of the sams genes.

W Houthoofd et al. (2002) European Worm Meeting "Embryonic development of the free-living, marine nematode Pellioditis marina"

G Borgonie, A Coomans, B Vancoppenolle, K Jacobsen, W Houthoofd

[European Worm Meeting, 2002]

Until now only the embryonic cell lineage of the model organism Caenorhabditis elegans has been described (Sulston et al., 1983). The embryonic cell lineage of the free-living nematode Pellioditis marina has been traced from zygote up until the initiation of muscle contraction by means of 4D-microscopy, marking the second detailed description of the embryonic development of a nematode. P. marina is a close relative of C. elegans, but has adapted to a marine, brackish environment. The overall lineage resembles strongly on that of C. elegans, with a few small differences. The developmental tempo of the early embryogenesis (until division of E cell) is more then two times slower than C. elegans. But the primordial germline cell P4 is already present at the 15-cell stage (in C. elegans at the 24-cell stage). At the stage of muscle contraction (when most cells are established), P. marina has as many cells as C. elegans (571 cells) but less cell deaths (67 and 106 respectively). Tissue conservation varies from highly conserved to highly variable. The intestine, the primordial gonad and the body muscles are highly conserved in the two species, while the pharynx, the epidermis and the nervous system have a more variable configuration. The systematic position of Pellioditis remains unsolved, whether Caenorhabditis or Rhabditis is the closest relative. The early embryogenesis and the developmental timing are comparable with that of other Rhabditis species, while the overall cell lineage is almost identical with that of C. elegans. The latter is a strong argument to place P. marina close to C. elegans in the classification. In more primitive nematodes (like Halicephalobus sp.), sublineages form identical cells, which migrate to their exact location. C. elegans has adjusted these lineages to avoid these migrations (Borgonie et al., 2000). This could explain the chaotic' fate topology in the C. elegans cell lineage. P. marina falls in between: it has already adjusted the Caa-lineage to form two nerve cells, but still has migrations that are avoided in C. elegans.

Soboslay PT et al. (2010) Wien Klin Wochenschr "Applied field research for comprehensive helminth infection control."

Schulz-Key H, Stingl P, Djassoa G, Karabou PK, Hamm DM, Douti JK, Heuschkel C, Agossou A, Gantin RG, Soboslay PT, Banla M

[Wien Klin Wochenschr, 2010]

The Institute for Tropical Medicine at University of Tubingen has established 30 years ago in Togo a Research Centre and Onchocerciasis Reference Laboratory (ORL). Onchocerca volvulus infection control and of other neglected tropical diseases has been the focus of activities, and those were performed together with the National Institute of Hygiene in Togo, the Medical Faculty at University of Lome, national disease control programs and district and regional hospitals. The ORL contributed significantly to the assessment of ivermectin as the prime choice for onchocerciasis treatment, and 24 years of repeated annual treatment with ivermectin has progressively reduced disease prevalence and notably the level of ocular and dermal manifestations of onchocerciasis in the endemic population. The ORL has shown that large parts of the rural population in Togo is concurrently infected with intestinal and intravascular protozoan and helminth parasites, notably school children. The application of repeated treatments with albendazole and praziquantel against Schistosoma spp. and instestinal helminthes for several years has reduced infection intensities by more than 80%. Longitudinal investigations of the cellular immune responses in adults and children have found that parasite co-infections will generate prominent pro-inflammatory responses, and a single or few interventions will not suffice to eliminate co-infections and not establish an appropriately balanced immunity.

Korbmacher F et al. (2018) Parasite Epidemiol Control "Mansonella perstans, Onchocerca volvulus and Strongyloides stercoralis infections in rural populations in central and southern Togo."

Padjoudoum K, Karabou P, Korbmacher F, Soboslay PT, Gantin RG, Poutouli WP, Kohler C, Komlan K

[Parasite Epidemiol Control, 2018]

Background: are important especially under the aspect of MDA of ivermectin which is performed since decades. Methods: =924) were collected from rural populations in the Regions Central and Plateaux in Togo, and analyzed by parasite-specific real-time PCR and ELISA techniques. Results: were 9.9%. Conclusions: may be ongoing. The degree of positive test results in the examined rural communities advocate for the continuation of MDA with ivermectin and albendazole, and further investigations should address the intensity of transmission of these parasites.

(2011) MMWR Morb Mortal Wkly Rep "Progress toward elimination of lymphatic filariasis--Togo, 2000--2009."

[MMWR Morb Mortal Wkly Rep, 2011]

Lymphatic filariasis (LF) is a disabling, mosquito-borne disease of humans caused by the parasitic filarial nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori. In 2000, the Global Program to Eliminate LF (GPELF) was established with the objective of eliminating LF as a public health problem by 2020. At that time, 80 countries had ongoing transmission, with an estimated 1.34 billion persons at risk for infection and 120 million infected. This report describes the LF elimination program in Togo, one of the 39 LF-endemic countries in the World Health Organization (WHO) African Region. Togo's approach to interrupt LF transmission included screening for infection to identify LF-endemic districts and mass drug administration (MDA) of ivermectin and albendazole in LF-endemic districts. MDA coverage and the impact of MDAs on the prevalence of infection were monitored throughout the program. In 2000, seven of 35 districts were LF-endemic, with baseline prevalence rates ranging from 1% to 22%. By 2009, MDAs had been conducted at least six times in each LF-endemic district. At that time, the decision was made to stop MDAs because reported drug coverage in LF-endemic districts exceeded 80% and no microfilaremia was detected in persons tested to monitor impact of MDAs. Togo is the first sub-Saharan country to have stopped MDAs after prevalence data suggested that LF transmission had been interrupted. Post-MDA surveillance is continuing nationally; the next step will be to certify elimination. The successful Togo program demonstrates that LF elimination can be achieved in countries with limited resources.

Komlan K et al. (2018) PLoS Negl Trop Dis "Onchocerca volvulus infection and serological prevalence, ocular onchocerciasis and parasite transmission in northern and central Togo after decades of Simulium damnosum s.l. vector control and mass drug administration of ivermectin."

Soboslay PT, Vossberg PS, Solim T, Korbmacher F, Kohler C, Gantin RG, Komlan K, Banla M, Karabou P, Padjoudoum K

[PLoS Negl Trop Dis, 2018]

BACKGROUND: Mass drug administration (MDA) of ivermectin has become the main intervention to control onchocerciasis or "river blindness". In Togo, after many years of MDA, Onchocerca volvulus infection has declined dramatically, and elimination appears achievable, but in certain river basins the current situation remains unknown. We have conducted parasitological, serological, ophthalmological, and entomological assessments in northern and central Togo within the river basins of Oti, Keran and Mo. METHODOLOGY/PRINCIPAL FINDINGS: Examinations were completed in 1,455 participants from 11 onchocerciasis sentinel villages, and O. volvulus transmission by Simulium damnosum sensu lato (s.l.) was evaluated. In children (aged 1-10 years), the prevalence of microfilariae (Mf) was 2.3% and in adults it ranged from 5.1 to 13.3%. Positive IgG4 responses to O. volvulus adult (crude) worm antigen (OvAg) and the recombinant Ov16 antigen were in all-ages 48.7% and 34.4%, and 29.1% and 14.9% in children, respectively. In the river basin villages of Keran, Mo and Oti, the IgG4 seroprevalences to OvAg in children were 51.7%, 23.5% and 12.7%, respectively, and to the Ov16 antigen 33.3% (Keran) and 5.2% (Oti). Onchocerciasis ocular lesions (punctate keratitis, evolving iridocyclitis and chorioretinitis) were observed in children and young adults. O. volvulus-specific DNA (Ov150) was detected by poolscreen in vector samples collected from Tchitchira/Keran(22.8%), Bouzalo/Mo(11.3%), Baghan/Mo(2.9%) and Pancerys/Oti(4.9%); prevalences of O. volvulus infection in S. damnosum s.l. were, respectively, 1%, 0.5%, 0.1% and 0.2%. CONCLUSIONS/SIGNIFICANCE: In the northern and central river basins in Togo, interruption of O. volvulus transmission has not yet been attained. Patent O. volvulus infections, positive antibody responses, progressive ocular onchocerciasis were diagnosed, and parasite transmission by S. damnosum s.l. occurred close to the survey locations. Future interventions may require approaches selectively targeted to non-complying endemic populations, to the seasonality of parasite transmission and national onchocerciasis control programs should harmonize cross-border MDA as a coordinated intervention.

Wu Y et al. (2003) Filaria J "Human immune responses to infective stage larval-specific chitinase of filarial parasite, Onchocerca volvulus, Ov-CHI-1."

Nutman TB, Bianco AE, McCarthy JS, Wu Y, Egerton G

[Filaria J, 2003]

BACKGROUND: Ov-CHI-1 is a chitinase specifically expressed in the infective stage larvae of the human filarial parasite Onchocerca volvulus. Evidence has show that it could be a vaccine candidate, however, there is no data available regarding the immunological status of people naturally exposed to infective stage larvae and thus provoked by this antigen. METHOD: We analysed the Ov-CHI-1-specific immune response present in four endemic foci of human onchocerciasis (Ecuador, Nigeria, Togo and Cameroon) by enzyme-linked immunosorbent assays and T-cell proliferation assays. RESULTS: In these foci of infection, antibodies to Ov-CHI-1 were found to be present in only 22% of individuals from Ecuador, but were detected in 42-62% of infected individuals in the three foci from West Africa (Nigeria, Togo and Cameroon). There was found to be no relationship between antibody level and age, gender, or infection intensity as indicated by microfilarial density and numbers of skin nodules. The isotype response to Ov-CHI-1 was dominated by the presence of IgG3, IgG1 was present to a lesser extent. Our results show a positive correlation between N- and C-termini of Ov-CHI-1 in their ability to provoke humoral and cellular immune responses in the human. Peripheral blood mononuclear cell (PBMC) proliferative responses to Ov-CHI-1 when assayed, were found to be significantly higher in the individuals from endemic areas and there was a statistically elevated response to Ov-CHI-1 in the infected individuals when compared to putative immune individuals. CONCLUSION: Ov-CHI-1 is an antigen that we have found strongly induces both humoral and cellular immune responses in humans.

Sudhaus W (1974) Zool. Jb. Syst. Bd. "Zur Systematik, Verbreitung, Okologie und Biologie neuer und wenig bekannter Rhabditiden (Nematoda) 2. Teil."

Sudhaus W

[Zool. Jb. Syst. Bd., 1974]

Five new species of the genus Rhabditis are described (Rh. riemanni n. sp., Rh. remanei n. sp., Rh. reciproca n. sp., Rh. blumi n. sp., and Rh. valida n. sp.) belonging to five subgenera (Crustorhabditis, Caenorhabditis, Rhabditis, Cephaloboides, and Pellioditis). The descriptions of four additional species are revised (Rh. ocypodis Chitwood, Rh. scanica Allgen, Rh. plicata Volk, and Rh. bengalensis Timm). The new subgenus Crustorhabditis n. subgen. derives from the paraphyletic subgenus Mesorhabditis. The species of the former group show a transition from living in littoral seaweed deposits to an obligate association with amphibious crabs (Crustacea). Information about the distribution, ecology, biology and ethology of all these species is presented (with two distribution maps, one for Rh. marina for comparison). Supplementary notes are given from Protorhabditis oxyuroides Sudhaus and Rhabditis tripartita von Linstow.