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1.
Parasitol Int ; 85: 102430, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34339857

RESUMO

Originally described from the masked greenling Hexagrammos octogrammus (Pallas, 1814), the palaeacanthocephalan Echinorhynchus hexagrammi Baeva, 1965 has so far been known from seven species in six families of marine teleosts distributed in the Sea of Okhotsk off Sakhalin and in the Northwestern Pacific off Hokkaido, Japan. In this study, we examined the phylogenetic position of E. hexagrammi based on material obtained from the intestine of an unidentified snailfish, Liparis sp., dredged in Akkeshi Bay, Hokkaido, Japan. We performed an analysis using two gene markers, the mitochondrial cytochrome c oxidase subunit I and the nuclear 28S rRNA, along with other sequences available in public databases. In the resulting tree, E. hexagrammi was more closely related to two species complexes, the E. bothniensis Zdzitowiecki and Valtonen, 1987 complex and the E. gadi Zoega in Müller, 1776 complex, rather than to E. brayi Wayland, Sommerville, and Gibson, 1999, E. cinctulus (Porta, 1905), E. salmonis Müller, 1784, and E. truttae Schrank, 1788. The morphology of the examined material herein identified as E. hexagrammi is briefly described. This study represents the first host record of E. hexagrammi from the snailfish family Liparidae.


Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , Peixes/parasitologia , Acantocéfalos/classificação , Animais , Complexo IV da Cadeia de Transporte de Elétrons/análise , Proteínas de Helminto , Interações Hospedeiro-Parasita , Perciformes/parasitologia , RNA de Helmintos/análise , RNA Ribossômico 28S/análise
2.
Science ; 373(6558): 984-991, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34446600

RESUMO

Protein kinase activity must be precisely regulated, but how a cell governs hyperactive kinases remains unclear. In this study, we generated a constitutively active mitogen-activated protein kinase DYF-5 (DYF-5CA) in Caenorhabditis elegans that disrupted sensory cilia. Genetic suppressor screens identified that mutations of ADR-2, an RNA adenosine deaminase, rescued ciliary phenotypes of dyf-5CA We found that dyf-5CA animals abnormally transcribed antisense RNAs that pair with dyf-5CA messenger RNA (mRNA) to form double-stranded RNA, recruiting ADR-2 to edit the region ectopically. RNA editing impaired dyf-5CA mRNA splicing, and the resultant intron retentions blocked DYF-5CA protein translation and activated nonsense-mediated dyf-5CA mRNA decay. The kinase RNA editing requires kinase hyperactivity. The similar RNA editing-dependent feedback regulation restricted the other ciliary kinases NEKL-4/NEK10 and DYF-18/CCRK, which suggests a widespread mechanism that underlies kinase regulation.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Cílios/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Edição de RNA , Adenosina Desaminase/genética , Adenosina Desaminase/metabolismo , Animais , Caenorhabditis elegans/genética , Núcleo Celular/metabolismo , Cílios/enzimologia , Ativação Enzimática , Fenótipo , Biossíntese de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Splicing de RNA , Estabilidade de RNA , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA de Helmintos/genética , RNA de Helmintos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Transcrição Genética
3.
Elife ; 102021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34323215

RESUMO

The translation initiation complex eIF3 imparts specialized functions to regulate protein expression. However, understanding of eIF3 activities in neurons remains limited despite widespread dysregulation of eIF3 subunits in neurological disorders. Here, we report a selective role of the C. elegans RNA-binding subunit EIF-3.G in shaping the neuronal protein landscape. We identify a missense mutation in the conserved Zinc-Finger (ZF) of EIF-3.G that acts in a gain-of-function manner to dampen neuronal hyperexcitation. Using neuron-type-specific seCLIP, we systematically mapped EIF-3.G-mRNA interactions and identified EIF-3.G occupancy on GC-rich 5'UTRs of a select set of mRNAs enriched in activity-dependent functions. We demonstrate that the ZF mutation in EIF-3.G alters translation in a 5'UTR-dependent manner. Our study reveals an in vivo mechanism for eIF3 in governing neuronal protein levels to control neuronal activity states and offers insights into how eIF3 dysregulation contributes to neurological disorders.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Fator de Iniciação 3 em Eucariotos/genética , Neurônios/fisiologia , Biossíntese de Proteínas , RNA de Helmintos/biossíntese , RNA Mensageiro/biossíntese , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fator de Iniciação 3 em Eucariotos/metabolismo
4.
Parasitol Int ; 84: 102412, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34166787

RESUMO

Current article touched upon the issue of the complicated taxonomic status of some species from the genus Crepidostomum collected from the freshwater fish in the rivers of Primorsky region, Sakhalin, and Hokkaido Islands. Primary morphological analyses showed affiliation of the worms to the species C. farionis (Müller, 1784) Lühe, 1909; C. metoecus Braun, 1900b; C. chaenogobii Yamaguti and Matsumura, 1942; C. nemachilus Krotov, 1959. We described the new species Crepidostomum achmerovi sp. nov. that is a sibling species of C. nemachilus. Molecular-genetic investigation have shown that C. nemachilus and C. achmerovi sp. nov. are closely related to C. metoecus in both 28S rDNA and cox1 mtDNA markers. Crepidostomum nemachilus forms a separate branch within the C. metoecus clade on the 28S BI tree with strong statistical support and separate clade in relation to C. metoecus clade on the cox1 BI tree. Values of p-distances between Crepidostomum species were at intergeneric level. Crepidostomum metoecus species complex including five species (C. metoecus, C. nemachilus, C. oschmarini, C. brinkmanni, and C. achmerovi sp. nov.) was reconsidered as independent genus Crepidostomum sensu stricto. Minimum Spanning Network showed that C. nemachilus, C. metoecus and C. achmerovi sp. nov. were separated by large number of mutational events and represent independent phyletic lines. An amended diagnosis is provided for the subfamily Crepidostomatinae, the genera Crepidostomum s. str. and Stephanophiala Nicoll, 1909, along with keys to species of both genera.


Assuntos
Interações Hospedeiro-Parasita , Filogenia , Trematódeos/classificação , Animais , DNA de Helmintos/análise , DNA Mitocondrial/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Proteínas de Helminto/análise , Japão , RNA de Helmintos/análise , RNA Ribossômico 28S/análise , Sibéria , Trematódeos/anatomia & histologia , Trematódeos/genética
5.
Parasitol Int ; 84: 102398, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34087475

RESUMO

Tremiorchis is a monotypic genus of digenetic trematode (Plagiorchiidae: Plagiorchiinae), infecting the frogs Rana tigrina (Hoplobatrachus tigerinus) and R. cyanophlyctis (Euphlyctis cyanophlyctis). Metacercaria use to infect Rana tigrina (Hoplobatrachus tigerinus) and R. cyanophlyctis (Euphlyctis cyanophlyctis) as intermediate hosts, while the cercaria stage found from apple snail, Pila virens. Adults of T. ranarum harbor mature frogs of H. tigerinus and E. cyanophlyctis. Besides the frequent infection of Tremiorchis, no DNA sequence data are currently available for this monotypic genus. The present communication, deals with the sequence data for nuclear ribosomal genes, 18S, small internal transcribed spacers (ITS1-5.8S-ITS2) and 28S to molecularly characterize T. ranarum. Besides this, phylogenetic relationship among the members of the Plagiorchiida is also discussed in detail. An attempt has also been made to provide detailed molecular affinities of T. ranarum with other trematode genera.


Assuntos
Genes de Helmintos , RNA de Helmintos/análise , Trematódeos/classificação , Animais , Filogenia , RNA Ribossômico 18S/análise , RNA Ribossômico 28S/análise , Trematódeos/genética
6.
Elife ; 102021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34106046

RESUMO

Germ granules are protein-RNA condensates that segregate with the embryonic germline. In Caenorhabditis elegans embryos, germ (P) granule assembly requires MEG-3, an intrinsically disordered protein that forms RNA-rich condensates on the surface of PGL condensates at the core of P granules. MEG-3 is related to the GCNA family and contains an N-terminal disordered region (IDR) and a predicted ordered C-terminus featuring an HMG-like motif (HMGL). We find that MEG-3 is a modular protein that uses its IDR to bind RNA and its C-terminus to drive condensation. The HMGL motif mediates binding to PGL-3 and is required for co-assembly of MEG-3 and PGL-3 condensates in vivo. Mutations in HMGL cause MEG-3 and PGL-3 to form separate condensates that no longer co-segregate to the germline or recruit RNA. Our findings highlight the importance of protein-based condensation mechanisms and condensate-condensate interactions in the assembly of RNA-rich germ granules.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Grânulos Citoplasmáticos/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , RNA de Helmintos/metabolismo , Motivos de Aminoácidos , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/química , Grânulos Citoplasmáticos/química , Embrião não Mamífero , Proteínas Intrinsicamente Desordenadas/química , RNA de Helmintos/química
7.
Parasitol Int ; 83: 102371, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33932600

RESUMO

The present study describes Udonella brasiliensis n. sp., an epibiont found on Caligus sp., a parasite the ariids Genidens barbus (Lacepède) and Aspistor luniscutis (Valenciennes), caught on the coast of the state of São Paulo, Brazil. Morphological and molecular analyses (partial 18S rDNA) were carried out. The morphological data showed that U. brasiliensis n. sp. can be distinguished from current valid species by its morphometric attributes (e.g., body, pharynx, ovary and testis), while the molecular information supports the proposal of a new species. The 18S rDNA phylogenetic analysis shows a close relationship between the new species and Udonella australis Carvajal & Sepulveda, in a subclade formed of species that parasitize South American fish. Finally, this study also discusses a scenario of initial irradiation for udonellids.


Assuntos
Peixes-Gato , Copépodes/parasitologia , Doenças dos Peixes/epidemiologia , Simbiose , Trematódeos/anatomia & histologia , Trematódeos/genética , Infecções por Trematódeos/veterinária , Animais , Brasil/epidemiologia , Doenças dos Peixes/parasitologia , Filogenia , RNA de Helmintos/análise , RNA Ribossômico 18S/análise , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
8.
Parasitol Int ; 84: 102385, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34015519

RESUMO

The superfamily Cosmocercoidea comprises three families: Cosmocericidae, Kathlaniidae and Atractidae. Information on the nucleotide sequences of the Cosmocercoidea is quite limited, and the molecular classification of the whole superfamily has been slow to progress. The genus Grassenema of the family Atractidae is a parasitic nematode group that occurs in the digestive tract of hyraxes and includes three species: Grassenema procaviae, G. dendrohyraci, and G. hyracis. The type species of the genus, G. procaviae, was isolated from the digestive tract of Cape hyraxes (Procavia capensis) and has the potential to cause gastric ulcers. Although G. procaviae is a common parasite of Cape hyraxes, no genetic information for the parasite is currently available. In this study, we obtained the first genomic sequences of G. procaviae and performed detailed morphological observations. Furthermore, molecular phylogenetic analysis was performed, and the taxonomic position of the parasite was evaluated using 18S and 28S rDNA sequences. Those data will be useful for molecular identification of G. procaviae and future phylogenetic analysis within the Atractidae.


Assuntos
Procaviídeos , Infecções por Rhabditida/veterinária , Rabditídios/isolamento & purificação , Animais , Animais de Zoológico , Feminino , Japão , Masculino , Microscopia Eletrônica de Varredura/veterinária , Filogenia , RNA de Helmintos/análise , RNA Ribossômico 18S/análise , RNA Ribossômico 28S/análise , Rabditídios/genética , Rabditídios/ultraestrutura , Infecções por Rhabditida/parasitologia
9.
Parasitology ; 148(9): 1083-1091, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34027840

RESUMO

Estimates of trematode diversity are inaccurate due to unrecognized cryptic species and phenotypic plasticity within species. Integrative taxonomy (genetics, morphology and host use) increases the clarity of species delineation and improves knowledge of parasite biology. In this study, we used this approach to resolve taxonomic issues and test hypotheses of cryptic species in a genus of trematode, Quinqueserialis. Specimens from throughout North America were field collected from hosts and obtained from museums. We found three morphologically distinct groups and successfully sequenced specimens from two of these groups. DNA sequencing at the 28S and CO1 gene regions revealed that two of the three groups were genetically distinct. One genetic group included two morphological clusters demonstrating host-induced phenotypic plasticity within Quinqueserialis quinqueserialis. The other unique genetic group is a novel species, Quinqueserialis kinsellai n. sp., which is described herein. Our study illustrates the importance of integrating multiple sources of evidence when investigating trematode diversity to account for the influence of cryptic species or phenotypic plasticity. However, further sampling is needed to understand Quinqueserialis spp. diversity as some species have no genetic information associated with them.


Assuntos
Biodiversidade , Trematódeos/classificação , Animais , Canadá , Complexo IV da Cadeia de Transporte de Elétrons/análise , Proteínas de Helminto/análise , RNA de Helmintos/análise , RNA Ribossômico 28S/análise , Análise de Sequência de DNA , Trematódeos/anatomia & histologia , Trematódeos/enzimologia , Trematódeos/genética , Estados Unidos
10.
Mol Cell ; 81(11): 2388-2402.e8, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-33852894

RESUMO

Small RNA pathways defend the germlines of animals against selfish genetic elements, yet pathway activities need to be contained to prevent silencing of self genes. Here, we reveal a proteolytic mechanism that controls endogenous small interfering (22G) RNA activity in the Caenorhabditis elegans germline to protect genome integrity and maintain fertility. We find that DPF-3, a P-granule-localized N-terminal dipeptidase orthologous to mammalian dipeptidyl peptidase (DPP) 8/9, processes the unusually proline-rich N termini of WAGO-1 and WAGO-3 Argonaute (Ago) proteins. Without DPF-3 activity, these WAGO proteins lose their proper complement of 22G RNAs. Desilencing of repeat-containing and transposon-derived transcripts, DNA damage, and acute sterility ensue. These phenotypes are recapitulated when WAGO-1 and WAGO-3 are rendered resistant to DPF-3-mediated processing, identifying them as critical substrates of DPF-3. We conclude that N-terminal processing of Ago proteins regulates their activity and promotes silencing of selfish genetic elements by ensuring Ago association with appropriate small RNAs.


Assuntos
Proteínas Argonauta/genética , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Processamento de Proteína Pós-Traducional , RNA de Helmintos/genética , Animais , Proteínas Argonauta/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Dipeptidil Peptidases e Tripeptidil Peptidases/metabolismo , Fertilidade/genética , Proteólise , RNA de Helmintos/antagonistas & inibidores , RNA de Helmintos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Especificidade por Substrato
11.
Parasitol Int ; 83: 102359, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33878480

RESUMO

A case of abdominal dioctophymosis in a domestic cat was found in San Juan Bautista district, the Peruvian rainforest, in the Loreto department of Peru. The pet went to a veterinary clinic for a routine ovariohysterectomy during which a large nematode was found in the abdominal cavity. The nematode was morphologically identified as an adult female of Dioctophyme sp. A few morphological parameters, such as the vagina distance from the anterior part and the egg size, were different than D. renale. Partial sequences of the cytochrome c oxidase subunit I (cox1) and the small subunit 18S ribosomal RNA genes were compared with the references from public sequence database and showed a genetic identifies of 89.25% and 99.65% with D. renale, respectively. This is the first mitochondrial molecular analysis of a Dioctophyme specimen from South America and the results showed up to 12.5% nucleotide sequence variation in cox 1 gene of D. renale.


Assuntos
Doenças do Gato/parasitologia , Dioctophymatoidea/isolamento & purificação , Infecções por Enoplida/veterinária , Infecções Intra-Abdominais/veterinária , Animais , Doenças do Gato/diagnóstico , Gatos , Ciclo-Oxigenase 1/análise , Dioctophymatoidea/classificação , Infecções por Enoplida/diagnóstico , Infecções por Enoplida/parasitologia , Feminino , Proteínas de Helminto/análise , Infecções Intra-Abdominais/diagnóstico , Infecções Intra-Abdominais/parasitologia , Peru , RNA de Helmintos/análise , RNA Ribossômico 18S/análise , Floresta Úmida , Análise de Sequência de DNA/veterinária , Análise de Sequência de RNA/veterinária
12.
Philos Trans R Soc Lond B Biol Sci ; 376(1826): 20200112, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33866817

RESUMO

For decades, it was thought that the only heritable information transmitted from one individual to another was that encoded in the DNA sequence. However, it has become increasingly clear that this is not the case and that the transmission of molecules from within the cytoplasm of the gamete also plays a significant role in heritability. The roundworm, Caenorhabditis elegans, has emerged as one of the leading model organisms in which to study the mechanisms of transgenerational epigenetic inheritance (TEI). Collaborative efforts over the past few years have revealed that RNA molecules play a critical role in transmitting transgenerational responses, but precisely how they do so is as yet uncertain. In addition, the role of histone modifications in epigenetic inheritance is increasingly apparent, and RNA and histones interact in a way that we do not yet fully understand. Furthermore, both exogenous and endogenous RNA molecules, as well as other environmental triggers, are able to induce heritable epigenetic changes that affect transcription across the genome. In most cases, these epigenetic changes last only for a handful of generations, but occasionally can be maintained much longer: perhaps indefinitely. In this review, we discuss the current understanding of the role of RNA and histones in TEI, as well as making clear the gaps in our knowledge. We also speculate on the evolutionary implications of epigenetic inheritance, particularly in the context of a short-lived, clonally propagating species. This article is part of the theme issue 'How does epigenetics influence the course of evolution?'


Assuntos
Caenorhabditis elegans/genética , Cromatina/genética , Epigênese Genética , MicroRNAs/genética , RNA de Helmintos/genética , Animais
13.
J Parasitol ; 107(2): 214-221, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33684198

RESUMO

Urocleidus sayani n. sp. is described from the gills of pirate perch (Aphredoderus sayanus) in the Wisconsin backwaters of the upper Mississippi River and was found in samples from the Southeastern United States. Urocleidus sayani n. sp. is the second monogenean described from the pirate perch and the first for this host within Dactylogyridae. The description includes a partial 18S rRNA gene sequence (623 bp), filling a void in sequence data from North American monogeneans.


Assuntos
Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Percas/parasitologia , Platelmintos/classificação , Animais , Platelmintos/anatomia & histologia , Platelmintos/genética , Platelmintos/isolamento & purificação , RNA de Helmintos/genética , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , Rios , Estados Unidos , Wisconsin
14.
Elife ; 102021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33729152

RESUMO

Transgenerational inheritance of small RNAs challenges basic concepts of heredity. In Caenorhabditis elegans nematodes, small RNAs are transmitted across generations to establish a transgenerational memory trace of ancestral environments and distinguish self-genes from non-self-elements. Carryover of aberrant heritable small RNA responses was shown to be maladaptive and to lead to sterility. Here, we show that various types of stress (starvation, high temperatures, and high osmolarity) induce resetting of ancestral small RNA responses and a genome-wide reduction in heritable small RNA levels. We found that mutants that are defective in various stress pathways exhibit irregular RNAi inheritance dynamics even in the absence of stress. Moreover, we discovered that resetting of ancestral RNAi responses is specifically orchestrated by factors that function in the p38 MAPK pathway and the transcription factor SKN-1/Nrf2. Stress-dependent termination of small RNA inheritance could protect from run-on of environment-irrelevant heritable gene regulation.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , RNA de Helmintos/genética , Estresse Fisiológico/fisiologia , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , RNA de Helmintos/metabolismo , Estresse Fisiológico/genética
15.
Parasitol Int ; 83: 102318, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33689826

RESUMO

An unknown species of the genus Notocotylus (Digenea: Notocotylidae) was found as the larval stage from the lymnaeid snail, Radix auricularia, in a static water area of the Chubetsu River, Hokkaido, the northernmost island of Japan. A DNA barcoding identification system was applied to detect the adult stage. Through the inspection of anatid game birds in Hokkaido, Anas crecca, Anas platyrhynchos, Anas zonorhyncha, and Mareca penelope were demonstrated to serve as the definitive hosts. The detailed morphological features of the species were characterized using adults raised experimentally in immunosuppressed mice and naturally developed larvae in R. auricularia. Although the species is morphologically similar to Notocotylus attenuatus and Notocotylus magniovatus in both adult and larval stages, its taxonomic independence was confirmed by a comprehensive study based on molecular phylogeny, morphology, and ecology. Here we propose Notocotylus ikutai n. sp. for this species. The migratory behavior of the anatid hosts and the North-Eurasian distribution of R. auricularia suggest that the new species is widely distributed in the northern Far East.


Assuntos
Doenças das Aves/epidemiologia , Patos , Caramujos/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Animais Selvagens , Doenças das Aves/parasitologia , Japão/epidemiologia , Microscopia Eletrônica de Varredura , Filogenia , Prevalência , RNA de Helmintos/análise , RNA Ribossômico 28S/análise , Trematódeos/citologia , Trematódeos/genética , Trematódeos/ultraestrutura , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
16.
Parasitol Int ; 83: 102329, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33753234

RESUMO

The cryptic diversity of trematodes was evaluated in the Nagayama-Shinkawa River, an artificial canal of the Ishikari River System of Hokkaido, Japan. Numerous migratory waterfowls use the canal as a stopover point in every spring season. The lymnaeid snail, Radix auricularia, and the semisulcospirid snail, Semisulcospira libertina, colonize the static and flowing water areas, respectively. The trematode fauna of the two snails was assessed by molecular phylogenetic and population genetic analyses. Each of distinctive clades in mitochondrial DNA trees was arbitrarily set as a species. In total, 14 species of the families Diplostomidae, Echinostomatidae, Notocotylidae, Plagiorchiidae, and Strigeidae occurred in R. auricularia, wherease S. libertina harbored 10 species of the families Echinochasmidae, Heterophyidae, Notocotylidae, and Lecithodendridae and Cercaria creta, an unclassified species whose adult stage is still unknown. The species diversity of the larval trematodes could be recognized as a "hot spot", suggesting that the seasonal visit of waterfowls is very important to spread trematodes and to keep their diversity. A high intraspecific genetic diversity was observed in the echinostomatid, notocotylid, echinochasmid, and heterophyid species, whose definitive hosts include birds. It seems likely that each of the parasite populations is always disturbed by repeated visits of waterfowls.


Assuntos
Interações Hospedeiro-Parasita , Caramujos/parasitologia , Trematódeos/fisiologia , Migração Animal , Animais , Anseriformes/fisiologia , Japão , Filogenia , RNA de Helmintos/análise , RNA Ribossômico 28S/análise , Rios/parasitologia , Estações do Ano
17.
Vet Parasitol ; 292: 109396, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33711620

RESUMO

Cestodes belonging to the genus Raillietina are a major veterinary health problem in the poultry industry, especially in chickens (Gallus gallus domesticus) and ducks (Anas playtrhynchos domesticus). In this study, loop-mediated isothermal amplification coupled with a lateral flow dipstick (LAMP-LFD) assay was established and validated for the detection of R. echinobothrida, R. tetragona, and R. cesticillus in one reaction. The LAMP-LFD assay can be completed in 75 min under isothermal conditions at 66 °C and the results can be obtained by observation with the naked eye. This assay was very specific and had no cross-amplification with other closely related parasites (Cotugnia sp., Diorchis formosensis, Fimbriaria sp., Echinostoma sp., E. miyagawai, Hypoderaeum conoideum, Prosthogonimus cuneatus, and Ascaridia galli) or their definitive hosts (G. g. domesticus, A. p. domesticus). The sensitivity of the LAMP-LFD assay was detected with three Raillietina species at 0.5 ng, which was enough for gravid proglottid DNA detection. The accuracy test showed that the LAMP-LFD assay demonstrated accurate verification results when compared to morphological results. This is a novel LAMP-LFD assay that is highly specific and sensitive for the detection of Raillietina species. It can be applied to detection for epidemiological investigations, monitoring programs, surveillance, control, and to solve veterinary health problems for the poultry industry in Raillietina endemic areas.


Assuntos
Cestoides/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Animais , Cestoides/classificação , Cestoides/genética , DNA de Helmintos/genética , RNA de Helmintos/genética , RNA Ribossômico 28S/genética , Especificidade da Espécie
18.
Mol Immunol ; 134: 150-160, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33773158

RESUMO

In the last years, cell free or extracellular RNAs (ex-RNAs) have emerged as novel intercellular messengers between animal cells, including pathogens. In infectious diseases, ex-RNAs represent novel players in the host-pathogen and pathogen-pathogen interplays and have been described in parasitic helminths from the three major taxonomic groups: nematodes, trematodes and cestodes. Altogether, it is estimated that approximately 30 percent of the world's population is infected with helminths, which cause debilitating diseases and syndromes. Ex-RNAs are protected from degradation by encapsulation in extracellular vesicles (EV), or association to proteins or lipoproteins, and have been detected in the excretion/secretion products of helminth parasites, with EV as the preferred extracellular compartment under study. EV is the generic term used to describe a heterogenous group of subcellular membrane-bound particles, with varying sizes, biogenesis, density and composition. However, recent data suggests that this is not the only means used by helminth parasites to secrete RNAs since ex-RNAs can also be found in EV-depleted samples. Furthermore, the use of pathogen ex-RNAs as biomarkers promise the advent of new diagnostic tools though this field is still in early stages of exploration. In this review, we summarize current knowledge of vesicular and non-vesicular ex-RNAs secretion in helminth parasites, their potential as biomarkers and the evidence of their role in parasite and host reciprocal communication, together with unanswered questions in the field.


Assuntos
Ácidos Nucleicos Livres , Interações Hospedeiro-Parasita , RNA de Helmintos , Animais , Helmintos , Humanos
19.
Parasitology ; 148(7): 787-797, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33678200

RESUMO

The large-sized tapeworm Dibothriocephalus latus is known as the broad or fish-borne cestode of mammals that is capable to infect humans and cause diphyllobothriosis. Recently, molecular data on D. latus has been accumulating in the literature and a complete genome sequence has been published; however, little is known about the karyotype and chromosome architecture. In this study, an in-depth karyological analysis of 2 D. latus specimens was carried out. The plerocercoids originated from a perch caught in subalpine Lake Iseo (Italy) and the tapeworms were reared in hamsters. Both specimens contained cells with a highly variable number of chromosomes ranging from18 to 27. Nevertheless, the largest portion of mitotic figures (47%) showed a number corresponding to the triploid set, 3n = 27. Accordingly, the karyotype of the analyzed specimens consisted of 9 triplets of metacentric chromosomes. Fluorescence in situ hybridization (FISH) with the 18S rDNA probe clearly demonstrated the presence of 3 clusters of hybridization signals on the triplet of chromosome 7, thus confirming the triploid status of the specimens. FISH with a telomeric (TTAGGG)n probe confined hybridization signals exclusively to the terminal chromosomal regions, supporting the earlier findings that this repetitive motif is a conserved feature of tapeworm telomeres.


Assuntos
Difilobotríase/parasitologia , Diphyllobothrium/genética , Triploidia , Animais , Cromossomos/genética , Análise Citogenética , Diphyllobothrium/metabolismo , Hibridização in Situ Fluorescente , Cariótipo , RNA de Helmintos/análise , RNA Ribossômico 18S/análise
20.
Parasitol Res ; 120(4): 1371-1377, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33624148

RESUMO

We report and discuss the surprising encounter of a dog naturally infected by Dracunculus sp. in Brazil, a brief clinical history of the animal and a procedure for removing the nematode. We also present details on the morphology of the fragments collected from the nematode and a phylogenetic comparison of the partial sequences of the mitochondrial 18S rRNA and cytochrome c oxidase subunit I (COI) genes, deposited with others in GenBank. The samples were an independent lineage forming a well-supported monophyletic assemblage with D. medinensis. We thus conclude that this species has not yet been sequenced or even described and will only be elucidated by more information because only two species of Dracunculus have been reported in Brazil, D. fuelleborni and D. brasiliensis.


Assuntos
Doenças do Cão/parasitologia , Dracunculíase/veterinária , Dracunculus/genética , Animais , Brasil , Cães , Dracunculíase/parasitologia , Dracunculus/anatomia & histologia , Dracunculus/classificação , Genes de Helmintos , Genes de RNAr , Masculino , Filogenia , RNA de Helmintos/genética , RNA Mitocondrial/genética , RNA Ribossômico 18S/genética
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