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1.
Korean J Parasitol ; 57(4): 417-422, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31533409

RESUMO

From October 2015 to August 2018, tapeworm proglottids were obtained from 10 patients who were residents of Daegu and Gyeongbuk provinces and had a history of raw beef consumption. Most of them had no overseas travel experience. The gravid proglottids obtained from the 10 cases had 15-20 lateral uterine branches. A part of internal transcribed spacer 1 (ITS1) DNA of the 10 cases, amplified by polymerase chain reaction (PCR) and digested with AleI restriction enzyme, produced the same band pattern of Taenia saginata, which differentiated from T. asiatica and T. solium. Sequences of ITS1 and cytochrome c oxidase subunit 1 (cox1) showed higher homology to T. saginata than to T. asiatica and T. solium. Collectively, these 10 cases were identified as T. saginata human infections. As taeniasis is one of the important parasitic diseases in humans, it is necessary to maintain hygienic conditions during livestock farming to avoid public health concerns.


Assuntos
DNA Espaçador Ribossômico/análise , Taenia saginata/isolamento & purificação , Teníase/diagnóstico , Adulto , Idoso , Animais , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , República da Coreia , Mapeamento por Restrição , Homologia de Sequência , Taenia saginata/classificação , Taenia saginata/genética , Teníase/parasitologia , Adulto Jovem
2.
Folia Parasitol (Praha) ; 662019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31490125

RESUMO

The first molecular assessment of phylogenetic relationships of cladorchiid digeneans (superfamily Paramphistomoidea Fischoeder, 1901) from freshwater fishes based on 28S rDNA, ITS2 and cox1 sequences reveals the subfamilies Dadayiinae Fukui, 1929 and Kalitrematinae Travassos, 1933 as non-monophyletic, whereas Dadaytrema Travassos, 1931 represented by three species is monophyletic. Fourteen species of cladorchiids were found in characiform, perciform and siluriform fishes in the Neotropical Region (Brazil and Peru), with numerous new host and geographical records. The first scanning electron micrographs of seven species are presented. Two new species of dadayiine and one new species of kalitrematine paramphistomes are described. Microrchis macrovarium sp. n. from Pimelodella cristata (Müller et Troschel) (type host), Tetranematichthys quadrifilis (Kner) and Pterodoras granulosus (Valenciennes) in Brazil and Peru differs from all three congeners in that the testes are directly tandem, not oblique, and that the ovary, between the caecal ends, is widely separated from the testes. Pronamphistoma philippei sp. n. from Heros sp. in Brazil is distinguished from the type and only species, Pronamphistoma cichlasomae Thatcher, 1992, by the absence of the anterior collar-like expansion present in the type species, the presence of extramural rather than intramural pharyngeal sacs, and the unusual development of the dorsal and ventral exterior circular muscle fibre series in the acetabulum. Pseudocladorchis romani sp. n. from P. granulosus (type host), Brachyplatystoma vaillantii (Valenciennes), Calophysus macropterus (Lichtenstein), Megalodoras uranoscopus (Eigenmann et Eigenmann) and Oxydoras niger (Valenciennes) in Brazil and Peru, is most similar to Pseudocladorchis nephrodorchis Daday, 1907 but differs in the shape of the testes (irregular, versus reniform in the latter species) and the size of the ovary (as large as, or larger than, the testes in the new species). The generic diagnosis of Pronamphistoma Thatcher, 1992 is amended. Dadaytremoides parauchenipteri Lunaschi, 1989 is transferred to Doradamphistoma Thatcher, 1979 as D. parauchenipteri (Lunaschi, 1989) comb. n. based on morphological and molecular evidence.


Assuntos
Distribuição Animal , Peixes-Gato , Caraciformes , Doenças dos Peixes/epidemiologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Brasil/epidemiologia , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Doenças dos Peixes/parasitologia , Proteínas de Helminto/análise , Microscopia Eletrônica de Varredura/veterinária , Peru/epidemiologia , Filogenia , Prevalência , RNA de Helmintos/análise , RNA Ribossômico 28S/análise , Trematódeos/anatomia & histologia , Trematódeos/genética , Trematódeos/ultraestrutura , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
3.
Folia Parasitol (Praha) ; 662019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31490126

RESUMO

Gnathostomes are of interest because of their unique appearance and medical importance. Among 13 valid species of the genus Gnathostoma Owen, 1836 (Nematoda: Spirurida), two species, G. doloresi Tubangui, 1925 and G. hispidum Fedtschenko, 1872, are parasites of pigs but their larvae can infect humans to cause gnathostomiasis. In this study, we collected adults of Gnathostoma sp. from the stomach of domestic pigs (Sus scrofa domesticus Linnaeus) from Dien Bien Province, northern Vietnam. Morphologically, nematodes found here are most similar to G. doloresi with a slight difference in the spicules of males. In contrast, they are genetically distinct from G. doloresi and other species of Gnathostoma in both ITS2 and cox1 sequences. The findings of the present study suggest that specimens of Gnathostoma sp. found in Dien Bien are likely a new species and emphasise the need of further studies on the taxonomy and phylogenetic relationship of species of Gnathostoma. Special attention should also be paid to swine and human gnathostomiasis in Dien Bien Province, Vietnam and the neighbouring areas of China and Laos.


Assuntos
Gnathostoma/anatomia & histologia , Gnathostoma/genética , Gnatostomíase/veterinária , Doenças dos Suínos/parasitologia , Animais , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Gnatostomíase/parasitologia , Proteínas de Helminto/análise , Masculino , Filogenia , Sus scrofa , Suínos , Vietnã
4.
J Insect Sci ; 19(4)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31422419

RESUMO

Torymus sinensis Kamijo (Hymenoptera: Torymidae) is an alien parasitoid that is used in many areas of the world for biological control the Asian chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae). In Italy, this parasitoid was imported from Japan in 2003 and subsequently multiplied and released throughout the country. In this study, a phylogenetic investigation was carried out on insects from three different sites in northern Tuscany (Italy). Moreover, the possible hybridization between T. sinensis and some native Torymus species was evaluated. The conserved region 18S rRNA gene and the hypervariable ITS2 (Internal Transcribed Spacer 2) region of the ribosomal cistrone were selected as molecular markers. Sequencing the amplified products, after cloning, ruled out any hybridization between T. sinensis and the native Torymus species, and also confirmed the presence of two haplotypes for the Tuscan population of T. sinensis both for the region of the 18S rRNA gene as well as for the ITS2 region. These results confirm that the environmental impact of the alien parasitoid T. sinensis in the study site is acceptable, although an extensive and repeated monitoring would be desirable.


Assuntos
DNA Espaçador Ribossômico/análise , DNA Ribossômico/análise , Genótipo , Controle Biológico de Vetores , Vespas/genética , Animais , Sequência de Bases , Hibridização Genética , Espécies Introduzidas , Itália , Filogenia , Alinhamento de Sequência , Vespas/classificação
5.
J Zoo Wildl Med ; 50(1): 254-257, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31120686

RESUMO

Mycoplasma species are important pathogens of captive and free-ranging chelonians. Bourret's box turtle (Cuora bourreti) is a critically endangered species of Indochinese box turtle in the family Geoemydidae. Four privately owned wild-caught Bourret's box turtles were presented for clinical evaluation for anorexia and lethargy following shipment from a reptile wholesaler 3 wk prior. Choanal-cloacal swabs of two of the turtles were positive for Mycoplasma sp. by polymerase chain reaction. Sequencing of the 16S rRNA gene and 16S-23S rRNA intergenic spacer was 99% homologous to an unclassified Mycoplasma sp. previously documented in free-ranging and captive North American species of the family Emydidae. The potential of Mycoplasma sp. to induce disease in Bourret's box turtles is unknown. Global trade in live reptiles is believed to have facilitated this potential expansion of host range.


Assuntos
Infecções por Mycoplasma/veterinária , Mycoplasma/isolamento & purificação , Tartarugas , Animais , DNA Espaçador Ribossômico/análise , Espécies em Perigo de Extinção , Feminino , Masculino , Mycoplasma/classificação , Mycoplasma/genética , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/microbiologia , Pennsylvania , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/análise , Análise de Sequência de DNA/veterinária
6.
Sci Total Environ ; 671: 140-148, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-30928743

RESUMO

Graphene oxide (GO) is an oxidized form of graphene that is relatively cheap and easy to produce. This has heralded its widespread use in a range of industries, with its likelihood of release into the environment increasing accordingly. In pure culture, GO has been shown to influence bacteria and fungi, but its effects on environmental microbial communities remain poorly characterized, despite the important ecosystem services that these organisms underpin. Here, we characterized the effects of GO and graphite, over time (7, 14 and 30 days) and at three concentrations (1 ng, 1 µg and 1 mg kg dry soil-1), on soil bacterial and fungal diversity using 16S rRNA and ITS2 gene amplicon sequencing. Graphite was included as a reference material as it is widely distributed in the environment. Neither GO or graphite had significant effects on the alpha diversity of microbial communities. The composition of bacterial and fungal communities, however, was significantly influenced by both materials at all doses. With the exception of the lowest GO dose on day 14, these effects were apparent for all treatments over the course of the experiment. Nonetheless, the effects of GO and graphite were of similar magnitude, albeit with some differences in the taxa affected.


Assuntos
Bactérias/efeitos dos fármacos , Fungos/efeitos dos fármacos , Grafite/efeitos adversos , Microbiota/efeitos dos fármacos , Poluentes do Solo/efeitos adversos , DNA Bacteriano/análise , DNA Fúngico/análise , DNA Espaçador Ribossômico/análise , Relação Dose-Resposta a Droga , RNA Bacteriano/análise , RNA Fúngico/análise , RNA Ribossômico 16S/análise , Microbiologia do Solo
7.
Malar J ; 18(1): 135, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992003

RESUMO

BACKGROUND: The recent finding of a typically non-African Anopheles species in eastern Ethiopia emphasizes the need for detailed species identification and characterization for effective malaria vector surveillance. Molecular approaches increase the accuracy and interoperability of vector surveillance data. To develop effective molecular assays for Anopheles identification, it is important to evaluate different genetic loci for the ability to characterize species and population level variation. Here the utility of the internal transcribed spacer 2 (ITS2) and cytochrome oxidase I (COI) loci for detection of Anopheles species from understudied regions of eastern Ethiopia was investigated. METHODS: Adult mosquitoes were collected from the Harewe locality (east) and Meki (east central) Ethiopia. PCR and Sanger sequencing were performed for portions of the ITS2 and COI loci. Both NCBI's Basic Local Alignment Search tool (BLAST) and phylogenetic analysis using a maximum-likelihood approach were performed to identify species of Anopheles specimens. RESULTS: Two species from the east Ethiopian collection, Anopheles arabiensis and Anopheles pretoriensis were identified. Analyses of ITS2 locus resulted in delineation of both species. In contrast, analysis of COI locus could not be used to delineate An. arabiensis from other taxa in Anopheles gambiae complex, but could distinguish An. pretoriensis sequences from sister taxa. CONCLUSION: The lack of clarity from COI sequence analysis highlights potential challenges of species identification within species complexes. These results provide supporting data for the development of molecular assays for delineation of Anopheles in east Ethiopia.


Assuntos
Anopheles/classificação , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Mosquitos Vetores/classificação , Animais , Anopheles/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Etiópia , Malária , Mosquitos Vetores/genética , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
8.
Med Vet Entomol ; 33(2): 296-311, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30739354

RESUMO

The human flea Pulex irritans Linnaeus, 1758 (Siphonaptera: Pulicidae) is one of the most studied species together with the cat flea Ctenocephalides felis Bouché, 1835, because they have a cosmopolitan distribution and are closely related to humans. The present study aimed to carry out a comparative morphometric and molecular study of two different populations of P. irritans (Spain and Argentina). Accordingly, internal transcribed spacer (ITS)1 and ITS2 of rDNA and the partial cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) mtDNA genes of these taxa were sequenced. Furthermore, the taxonomy, origin, evolution and phylogeny of P. irritans was assessed. The morphometric data obtained did not show significant differences between P. irritans specimens from Spain and Argentina, even when these two populations were collected from different hosts; however, there was a considerable degree of molecular divergence between both populations based on nuclear and mitochondrial markers. Thus, it is proposed that P. irritans, in contrast with other generalist fleas, maintains a certain degree of morphological similarity, at least between Western Palearctic and Neotropical areas. Furthermore, two well defined geographical genetic lineages within the P. irritans species are indicated, suggesting the existence of two cryptic species that could be discriminated by a polymerase chain reaction-linked restriction fragment length polymorphism.


Assuntos
Evolução Biológica , Sifonápteros/classificação , Animais , Argentina , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Proteínas de Insetos/análise , Masculino , Filogenia , Sifonápteros/anatomia & histologia , Sifonápteros/genética , Espanha
9.
Med Vet Entomol ; 33(3): 345-351, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30734975

RESUMO

Invasive Aedes mosquito species (Diptera: Culicidae) are of public health concern in Europe because they are either recognized or potential vectors of pathogens. Loop-mediated isothermal amplification (LAMP) is a rapid and simple method for amplifying DNA with high specificity and efficiency, with the technique having potential for application in the field, including in high-throughput format. Specific LAMP assays based on rDNA internal transcribed spacers 1 or 2 sequences, considering intraspecies variability at these loci, were developed for Aedes aegypti, Aedes albopictus, Aedes japonicus, Aedes koreicus and the indigenous Aedes geniculatus. No such assays could be developed for Aedes atropalpus and Aedes triseriatus because both loci were too short to serve as target. The assays rely on the clearly visible colour change from violet to sky blue after successful amplification. Sensitivity of egg detection was confirmed with ratios of up to one mosquito egg in 99 other eggs. Simple sample preparation of adults or eggs by mechanical homogenization in water required an additional heat treatment or centrifugation step to avoid non-specific colour changes. Thus, further technical improvements are needed to render these assays truly field-applicable, which would greatly facilitate surveillance of these invasive mosquito species and allow for prompt implementation of control measures.


Assuntos
Aedes/classificação , Mosquitos Vetores/classificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Aedes/genética , Animais , DNA Espaçador Ribossômico/análise , Espécies Introduzidas , Mosquitos Vetores/genética
10.
Insect Mol Biol ; 28(4): 485-498, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30632223

RESUMO

A recent DNA barcoding study of Australian microgastrines (Hymenoptera: Braconidae) sought to use next-generation sequencing of the cytochrome c oxidase subunit 1 (COI) barcoding gene region, the wingless (WG) gene and the internal transcribed spacer 2 (ITS2) to delimit molecular species in a highly diverse group of parasitic wasps. Large intragenomic distances between ITS2 variants, often larger than the average interspecific variation, caused difficulties in using ITS2 for species delimitation in both threshold and tree-based approaches, and the gene was not included in the reported results of the previous DNA barcoding study. We here report on the intragenomic, and the intra- and interspecies, variation in ITS2in the microgastrine genus Diolcogasterto further investigate the value of ITS2as a marker for species delimitation and phylogenetics of the Microgastrinae. Distinctive intragenomic variant patterns were found in different species of Diolcogaster, with some species possessing a single major variant, and others possessing many divergent variants. Characterizing intragenomic variation of ITS2is critical as it is a widely used marker in hymenopteran phylogenetics and species delimitation, and large intragenomic distances such as those found in this study may obscure phylogenetic signal.


Assuntos
Código de Barras de DNA Taxonômico , DNA Espaçador Ribossômico/análise , Filogenia , Vespas/classificação , Animais , Proteínas de Insetos/análise , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA , Vespas/genética
11.
Sci Total Environ ; 654: 960-968, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30453265

RESUMO

There is considerable debate regarding how the taxonomic diversity of microbial communities relates to the functional diversity across space while similar questions have been explored in macro-organism communities. Here, we investigated the taxonomic and functional diversity patterns of soil microbial communities by coupling the data obtained from marker genes sequencing and functional gene surveys. Meanwhile, we evaluated the relative effects of environment and geographic distance on shaping these patterns in alpine grasslands of northern China. Although the taxonomic diversity and composition of microbial communities varied across sites, we found no consistent changes in the functional structure. Both the environmental factors and geographic distance concurrently affected the taxonomic diversity patterns but they had no effects on the spatial variations in functional genes. The functional alpha diversity was weakly correlated to the taxonomic alpha diversity across sites. Moreover, we found no significant relationship between the taxonomic and functional composition similarity among microbial communities. Together, our results provide evidence that spatial variation in microbial functions could be independent of their variations in taxonomic diversity. Even the drivers of spatial variations in the functional structure could be totally different from those of taxonomic variations such as environmental differences and dispersal limitation. Our findings suggest that spatial variations of microbial function structure within a community would not follow the variations of taxonomic structures due to different drivers between both of them over space.


Assuntos
Pradaria , Microbiota , Microbiologia do Solo , Bactérias/genética , China , DNA Espaçador Ribossômico/análise , Genes Bacterianos , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Análise de Sequência de RNA
12.
Sci Total Environ ; 648: 1018-1030, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30340250

RESUMO

The aim of this study was to understand the responses of the microbial community of soil under different land uses to drought in a semi-arid Mediterranean area. In a laboratory incubation, soil samples from different land uses (natural forest, drip-irrigated orchard, rain-fed almond tree cultivation and abandoned area) were maintained at 20% and 60% of the WHC. The microbial biomass and potential enzyme activities were determined after four and fifty days of soil incubation. The diversity and composition of the microbial community were studied after 50 days of incubation. The total mineralisation of soil organic C (SOC), as well as, the mineralisation of fresh organic matter (FOM) and the "priming effect" were analysed after addition of 13C-enriched plant tissue. Both land use and drought had significant effects in the soil microbial community, but the effect of land use was stronger than that of drought. The PLFA content (microbial biomass) of the forests soil was greater under drought. After 50 days of soil incubation, the microbial biomass and most of potential enzyme activities of the almond tree and abandoned soil samples were not significantly affected by drought contrary to those in orchard soil. The total and FOM mineralisation were on average lower in soil under drought than under optimal moisture for all land uses. However, the responses of the priming effect to drought were dependent on the land use. Overall, we conclude that the resistance to drought of the soil microbial community from an agroecosystem having a semi-arid climate is strongly influenced by the previous land use.


Assuntos
Ciclo do Carbono , Secas , Ácidos Graxos/análise , Microbiologia do Solo , DNA Espaçador Ribossômico/análise , Microbiota , Ciclo do Nitrogênio , Compostos Orgânicos/metabolismo , Fósforo/metabolismo , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Espanha
13.
Pest Manag Sci ; 75(2): 356-365, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29888848

RESUMO

BACKGROUND: Pythium species attack various vegetable crops causing seed, stem and root rot, and 'damping-off' after germination. Pythium diseases are prevalently controlled by two classes of fungicides, QoIs with azoxystrobin and phenlyamides with mefenoxam as representatives. The present study aimed to test the sensitivity of six Pythium species from different vegetable crops to azoxystrobin and mefenoxam and differentiating species based on ITS, cytochrome b and RNA polymerase I gene sequences. RESULTS: The inter- and intra-species sensitivity to azoxystrobin was found to be stable, with the exception of one Pythium paroecandrum isolate, which showed reduced sensitivity and two cytochrome b amino acid changes. For mefenoxam, the inter-species sensitivity was quite variable and many resistant isolates were found in all six Pythium species, but no RNA polymerase I amino acid changes were observed in them. ITS and cytochrome b phylogenetic analyses permitted a clear separation of Pythium species corresponding to globose- and filamentous-sporangia clusters. CONCLUSION: The results document the necessity of well-defined chemical control strategies adapted to different Pythium species. Since the intrinsic activity of azoxystrobin among species was stable and no resistant isolates were found, it may be applied without species differentiation, provided it is used preventatively to also control highly aggressive isolates. For a reliable use of mefenoxam, precise identification and sensitivity tests of Pythium species are crucial because its intrinsic activity is variable and resistant isolates may exist. Appropriate mixtures and/or alternation of products may help to further delay resistance development. © 2018 Society of Chemical Industry.


Assuntos
Alanina/análogos & derivados , Fungicidas Industriais/farmacologia , Doenças das Plantas/classificação , Pirimidinas/farmacologia , Pythium/classificação , Pythium/efeitos dos fármacos , Estrobilurinas/farmacologia , Transportadores de Cassetes de Ligação de ATP/análise , Alanina/farmacologia , Sequência de Aminoácidos , Produtos Agrícolas/microbiologia , Citocromos b/química , Citocromos b/genética , Citocromos b/metabolismo , DNA Espaçador Ribossômico/análise , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Pythium/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Verduras/microbiologia
14.
J Phycol ; 54(6): 918-922, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30270437

RESUMO

Pseudo-nitzschia nanaoensis sp. nov. is described from waters around Nan'ao Island (South China Sea), using morphological data and molecular evidence. This species is morphologically most similar to P. brasiliana, but differs by a denser arrangement of fibulae, interstriae, and poroids, as well as by the structure of the valvocopula and the narrow second band. Pseudo-nitzschia nanaoensis constitutes a monophyletic lineage and is well differentiated from other species on the LSU and ITS2 sequence-structure trees. Pseudo-nitzschia nanaoensis makes up the basal node on the LSU tree, and forms a sister clade with a group of P. pungens and P. multiseries on the ITS2 tree. The ability of cultured strains to produce domoic acid was assessed, including its possible induction by the presence of a copepod and brine shrimp, by liquid chromatography-tandem mass spectrometry. However, no strains showed detectable domoic acid.


Assuntos
Diatomáceas/classificação , Ácido Caínico/análogos & derivados , Toxinas Marinhas/metabolismo , China , DNA de Protozoário/análise , DNA Espaçador Ribossômico/análise , Diatomáceas/citologia , Diatomáceas/genética , Diatomáceas/ultraestrutura , Ácido Caínico/metabolismo , Filogenia
15.
Exp Appl Acarol ; 76(1): 53-70, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30238307

RESUMO

Infestation by the ectoparasitic mite Sarcoptes scabiei (Acari: Sarcoptidae) has important implications for global wildlife conservation and both animal and human health. Ribosomal and mitochondrial DNA sequences of parasites are useful to determine genetic diversity and to describe their likely dynamic evolution. In this study, we described the genetic diversity of S. scabiei individuals collected from wild animals in China by sequencing the ribosomal ITS-2 and mitochondrial 16S rRNA genes. A total of 13 Sarcoptes isolates of wildlife, coupled with one of rabbit origin, were subjected to genetic characteristics. After cloning and sequencing, 14 ITS-2 sequences and 12 16S rRNA sequences were obtained and analyzed. Further analysis of haplotype network and population genetic structure revealed that there were 79 haplotypes in ITS-2 (main haplotype H2) and 31 haplotypes in 16S rRNA (main haplotype C10). The phylogenetic trees showed some partial clustering by location and host, and the analysis of gene polymorphism may prompt that all isolates of S. scabiei have a similar origin. We speculate that the genetic evolution of S. scabiei may be related with that of the hosts, but more research is necessary to better understand the host-parasite co-evolutionary relationship in S. scabiei. These results provide new insights into understanding the population genetics and evolutionary biology of S. scabiei and therefore a better understanding of controlling its infestation pathways worldwide.


Assuntos
Variação Genética , Ruminantes , Sarcoptes scabiei/genética , Animais , Animais Selvagens , DNA Intergênico/análise , DNA Espaçador Ribossômico/análise , Genes Mitocondriais , Cabras , RNA Ribossômico 16S/análise , Sarcoptes scabiei/fisiologia
16.
Ticks Tick Borne Dis ; 9(6): 1573-1585, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30100385

RESUMO

The aims of this work were to re-describe all parasitic stages of Rhipicephalus sanguineus sensu stricto, to select and deposit a neotype, and to characterize some of its diagnostic molecular traits. A male of R. sanguineus s.s. collected in Montpellier, France, was designated as neotype. The diagnostic characters unique to the male of R. sanguineus s.s. are: spiracular plate elongated and subtriangular in shape with a dorsal prolongation narrow and usually visible dorsally, with the dorsal prolongation narrower than the width of the adjacent festoon; punctations of the scutum moderate in number and unequal in size; marginal groove conspicuous, deep and punctate; posteromedian groove distinct and elongated, and posterolateral grooves often sub-circular, shorter than posteromedian groove; adanal plates long, wide, and subtriangular in shape, with a clear concavity in its inner margin and posterior margin broadly rounded or truncated; accessory adanal plates with the posterior end pointed, narrower than the width of adjacent festoon. The female of R. sanguineus s.s. can be diagnosed by a combination of broadly U-shaped genital aperture, spiracular plate with a narrow dorsal prolongation visible dorsally, basis capituli hexagonal with broad lateral angles, and scutum barely longer than broad with posterior margin sinuous and punctations moderate in number and unequal in size, larger and more numerous along cervical fields. The nymph has a basis capituli sub-triangular dorsally with lateral angles slightly curved and presence of ventral processes, scutum approximately as long as broad with lateral margins nearly straights, posterior margin broadly rounded, and cervical grooves short and sigmoid in shape extending posteriorly to the level of the eyes. The larva is characterized by basis capituli broader than long with lateral angles short and slightly curved and with posterior margin slightly convex, cervical grooves short, shallow and subparallel, and scutum almost twice broader than long. The phylogenetic analysis of DNA sequences support R. sanguineus s.s. as a well-defined taxon when compared with other species of the R. sanguineus group: R. turanicus s.s., R. camicasi, R. guilhoni, R. sulcatus, R. pusillus, R. rossicus and R. leporis. Molecularly R. sanguineus s.s. also encompasses the so-called "temperate lineage" from the New World (Argentina, southern Brazil, Chile, Uruguay, and USA). The evidence currently available supports the presence of R. sanguineus s.s. in Europe (France, Italy, Spain, Switzerland and Portugal) and America (Argentina, Brazil, Chile, Uruguay and U.S.A.), but further studies are needed to determine the exact geographic range of this taxon.


Assuntos
Rhipicephalus sanguineus/classificação , Rhipicephalus sanguineus/genética , Animais , Proteínas de Artrópodes/análise , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , França , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/genética , Ninfa/crescimento & desenvolvimento , RNA Ribossômico/análise , RNA Ribossômico 16S/análise , Rhipicephalus sanguineus/anatomia & histologia , Rhipicephalus sanguineus/crescimento & desenvolvimento , Análise de Sequência de RNA
17.
J Phycol ; 54(6): 811-817, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30137670

RESUMO

Light/scanning electron/transmission microscopy-based morphological analyses and multiple nucleotide sequences-based molecular phylogenetic analyses are used to identify and assess the phylogenetic position of a new unidentified green alga isolated from bleached corals living in the South China Sea. This new unidentified green alga is a unicellular marine alga and has uninucleate vegetative cells and multiple chloroplasts with a pyrenoid. It can form aplanosporangium covered by cell walls and reproduces by releasing autospore. These features differ substantially from those of the two genera Ignatius and Pseudocharacium. Those two genera have been accommodated in the Ignatius clade. Nucleotide sequences of the nuclear small subunit ribosomal RNA gene (18S rRNA), internal transcribed spacer 2 of ribosomal RNA gene (ITS2) and ribulose-1,5 bisphosphate carboxylase/oxygenase large subunit gene (rbcL, partial) are obtained and compared with published green algal sequences. The results from the morphology, ultrastructure, and multiple nucleotide sequences data support the placement of the new unidentified green alga in Ulvophyceae. This new unidentified isolate is described as Symbiochlorum hainanensis gen. et sp. nov., a new sister lineage to the Ignatius clade, Ulvophyceae, Chlorophyta.


Assuntos
Clorófitas/classificação , Microalgas/classificação , Filogenia , RNA de Algas/análise , Animais , Antozoários , China , Clorófitas/citologia , Clorófitas/enzimologia , Clorófitas/genética , DNA Espaçador Ribossômico/análise , Microalgas/citologia , Microalgas/enzimologia , Microalgas/genética , Oceano Pacífico , RNA Ribossômico 18S/análise , Ribulose-Bifosfato Carboxilase/análise , Simbiose
18.
Ann Bot ; 122(6): 1047-1059, 2018 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-30107389

RESUMO

Background and Aims: The origin of different cytotypes by autopolyploidy may be an important mechanism in plant diversification. Although cryptic autopolyploids probably comprise the largest fraction of overlooked plant diversity, our knowledge of their origin and evolution is still rather limited. Here we study the presumed autopolyploid aggregate of Aster amellus, which encompasses diploid and hexaploid cytotypes. Although the cytotypes of A. amellus are not morphologically distinguishable, previous studies showed spatial segregation and limited gene flow between them, which could result in different evolutionary trajectories for each cytotype. Methods: We combine macroevolutionary, microevolutionary and niche modelling tools to disentangle the origin and the demographic history of the cytotypes, using chloroplast and nuclear markers in a dense population sampling in central Europe. Key Results: Our results revealed a segregation between diploid and hexaploid cytotypes in the nuclear genome, where each cytotype represents a monophyletic lineage probably homogenized by concerted evolution. In contrast, the chloroplast genome showed intermixed connections between the cytotypes, which may correspond to shared ancestral relationships. Phylogeny, demographic analyses and ecological niche modelling supported an ongoing differentiation of the cytotypes, where the hexaploid cytotype is experiencing a demographic expansion and niche differentiation with respect to its diploid relative. Conclusions: The two cytotypes may be considered as two different lineages at the onset of their evolutionary diversification. Polyploidization led to the occurrence of hexaploids, which expanded and changed their ecological niche.


Assuntos
Aster/genética , Evolução Biológica , Filogenia , Poliploidia , DNA de Cloroplastos/análise , DNA Espaçador Ribossômico/análise , Europa (Continente) , Marcadores Genéticos , Modelos Biológicos , Filogeografia
19.
J Phycol ; 54(5): 638-652, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30055049

RESUMO

Two untapered, heterocytous species were observed and collected from the intertidal and supratidal zones of the Mexican coastline of the Pacific Ocean near Oaxaca and from the Gulf of Mexico. These populations were highly similar in morphology to the freshwater taxon Petalonema incrustans in the Scytonemataceae. However, 16S rRNA sequence data and phylogenetic analysis indicated that they were sister taxa to the epiphyllic, Brazilian species Phyllonema aveceniicola in the Rivulariaceae, described from culture material. While genetic identity between the two new species was high, they differed significantly in morphology, 16S rRNA gene sequence identity, and sequence and structure of the 16S-23S ITS region. Their morphology differed markedly from the generitype of the previously monotypic Phyllonema, which has tapered, heteropolar, single-false branched trichomes with very thin or absent sheath. The two new species, Phyllonema ansata and Phyllonema tangolundensis, described from both culture and environmental material, have untapered, isopolar, geminately false branched trichomes with thick, lamellated sheaths, differences so significant that the species would not be placed in Phyllonema without molecular corroboration. The morphological differences are so significant that a formal emendation of the genus is required. These taxa provide a challenge to algal taxonomy because the morphological differences are such that one would logically conclude that they represent different genera, but the phylogenetic evidence for including them all in the same genus is conclusive. This conclusion is counter to the current trend in algal taxonomy in which taxa with minor morphological differences have been repeatedly placed in separate genera based primarily upon DNA sequence evidence.


Assuntos
Cianobactérias/classificação , Cianobactérias/citologia , Proteínas de Algas/análise , Cianobactérias/genética , Cianobactérias/ultraestrutura , DNA Espaçador Ribossômico/análise , México , Filogenia , Estrutura Secundária de Proteína , RNA de Algas/análise , RNA Ribossômico 16S/análise , Análise de Sequência de RNA
20.
Harmful Algae ; 76: 80-95, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29887207

RESUMO

A field study was undertaken to investigate the occurrence and toxin production of species in the diatom genus Pseudo-nitzschia in Namibian waters, in the extremely productive Benguela upwelling system. From surveys conducted on the R/V Mirabilis and the R/V !Anichab, 52 strains were morphologically determined to species level, supported by nuclear ITS rDNA data. Seven species were identified; P. australis, P. decipiens, P. dolorosa, P. fraudulenta, P. plurisecta, P. pungens var. cingulata, and the new species P. bucculenta F. Gai, C. K. Hedemand, N. Lundholm & Ø. Moestrup sp. nov. Molecular and morphological diversity of the Namibian Pseudo-nitzschia species is discussed. Most importantly, P. bucculenta is both morphologically and phylogenetically most similar to P. dolorosa differing mainly in valve width and densities of striae, poroids and band striae as well as by four hemi-compensatory base changes in the ITS2. Morphological and molecular differences among the strains of P. decipiens suggest a temperate and a warm water subdivision. The geographical and toxigenic characteristics of the identified Pseudo-nitzschia species are described and compared to previous studies. Initial tests of toxin production in all seven species revealed production of domoic acid (DA) in two species: one strain of P. australis (0.074 pg DA cell-1) and two strains of P. plurisecta (0.338 pg DA cell-1 and 0.385 pg DA cell-1).


Assuntos
Diatomáceas/classificação , DNA de Algas/análise , DNA Espaçador Ribossômico/análise , Diatomáceas/química , Diatomáceas/genética , Diatomáceas/ultraestrutura , Toxinas Marinhas , Microscopia Eletrônica de Transmissão , Namíbia
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