RESUMEN
Hybridization and polyploidization are important evolutionary processes whose impacts range from the alteration of gene expression and phenotypic variation to the triggering of asexual reproduction. We investigated fishes of the Cobitis taenia-elongatoides hybrid complex, which allowed us to disentangle the direct effects of both processes, due to the co-occurrence of parental species with their diploid and triploid hybrids. Employing morphological, ecological, and RNAseq approaches, we investigated the molecular determinants of hybrid and polyploid forms. In contrast with other studies, hybridization and polyploidy induced relatively very little transgressivity. Instead, Cobitis hybrids appeared intermediate with a clear effect of genomic dosing when triploids expressed higher similarity to the parent contributing two genome sets. This dosage effect was symmetric in the germline (oocyte gene expression), interestingly though, we observed an overall bias toward C. taenia in somatic tissues and traits. At the level of individual genes, expression-level dominance vastly prevailed over additivity or transgressivity. Also, trans-regulation of gene expression was less efficient in diploid hybrids than in triploids, where the expression modulation of homoeologs derived from the "haploid" parent was stronger than those derived from the "diploid" parent. Our findings suggest that the apparent intermediacy of hybrid phenotypes results from the combination of individual genes with dominant expression rather than from simple additivity. The efficiency of cross-talk between trans-regulatory elements further appears dosage dependent. Important effects of polyploidization may thus stem from changes in relative concentrations of trans-regulatory elements and their binding sites between hybridizing genomes. Links between gene regulation and asexuality are discussed.
Asunto(s)
Cipriniformes/genética , Regulación de la Expresión Génica , Hibridación Genética , Poliploidía , Reproducción Asexuada , Animales , Cipriniformes/anatomía & histología , Cipriniformes/metabolismo , Ecosistema , Femenino , Masculino , FenotipoRESUMEN
Roots of terrestrial plants host a wide spectrum of soil fungi that form various parasitic, neutral and mutualistic associations. A similar trend is evident in freshwater aquatic plants and plants inhabiting salt marshes or mangroves. Marine vascular plants (seagrasses), by contrast, seem to lack specific root-fungus symbioses. We examined roots of two Mediterranean seagrasses, Posidonia oceanica and Cymodocea nodosa, in the northwestern Mediterranean Sea for fungal colonization using light and scanning and transmission electron microscopy. We found that P. oceanica, but not C. nodosa, is regularly associated with melanized septate hyphae in a manner resembling colonization by the ubiquitous dark septate endophytes (DSE) in roots of most terrestrial plants. P. oceanica roots were found to be colonized by sparse dematiaceous running hyphae as well as dense parenchymatous nets/hyphal sheaths on the root surface, intracellular melanized microsclerotia and occasionally also intra- and intercellular hyphae. The colonization was most prominent in the thick-walled hypodermis of the thinnest healthy looking roots, and the mycobiont seemed to colonize both living and dead host cells. Dark septate hyphae infrequently occurred also inside rhizodermal cells, but never colonized vascular tissues. The biological significance of this overlooked marine symbiosis remains unknown, but its morphology, extent, distribution across the NW Mediterranean Sea and absence in C. nodosa indicate an intriguing relationship between the dominant Mediterranean seagrass and its dark septate root mycobionts.
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Alismatales/microbiología , Endófitos/crecimiento & desarrollo , Mar Mediterráneo , Microscopía Electrónica de Transmisión , Micorrizas/crecimiento & desarrollo , Micorrizas/aislamiento & purificación , Raíces de Plantas/microbiología , SimbiosisRESUMEN
A survey of naso-pharyngeal and subcutaneous myiasis affecting roe deer (Capreolus capreolus) was conducted in the Czech Republic over an 8-year period (1999-2006). A total of 503 bucks and 264 does from six hunting localities were examined. The sampling area comprised predominantly agricultural lowlands and a mountain range primarily covered by forest. Since 1997, the deer have been treated each winter across the board with ivermectin (150 mg/kg, CERMIX® pulvis, Biopharm, CZ). Parasites found were the larvae of Hypoderma diana and Cephenemyia stimulator. There were no significant differences in warble fly infection among captured animals in the individual hunting localities. Overall, 146 (28.8%) of 503 animals (bucks) were infected with Cephenemyia stimulator larvae; body size of the second instar larva reached 13-18 mm. The prevalence ranged from 16.1 to 42.9% per year, and the mean intensity from 6 to 11 larvae per animal. Additionally, a total of 264 roe deer (does) were examined for H. diana larvae, and 77 (29.1%) were found to be positive; body size of the second instar larva reached 17 mm. The prevalence ranged from 18.8 to 50.0% per year, and the mean intensity from 13 to 22 larvae per animal. The results showed that the bot flies, Cephenemyia stimulator as well as H. diana, are common parasites in roe deer in the Czech Republic, and that through the help of treatment (ivermectin), it is possible to keep parasite levels low. The body weights of infected and non-infected H. diana deer did not differ significantly.
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Ciervos/parasitología , Dípteros/patogenicidad , Miasis/epidemiología , Animales , República Checa/epidemiología , Ivermectina/uso terapéutico , Miasis/parasitología , Nasofaringe/parasitología , Prevalencia , Tejido Subcutáneo/parasitologíaRESUMEN
Emerging contaminants and their pervasive presence in freshwater ecosystems have been widely documented, but less is known about their prevalence and the harm they cause in marine ecosystems, particularly in developing countries. This study provides data on the prevalence and risk posed by microplastics, plasticisers, pharmaceuticals and personal care products (PPCPs), and heavy metal(loid)s (HMs) along the Maharashtra coast of India. The sediment and coastal water samples were collected from 17 sampling stations, processed, and subjected to FTIR-ATR, ICP-MS, SEM-EDX, LC-MS/MS, and GC-MS for further analysis. Higher MPs abundance, combined with the pollution load index, indicates that the northern zone is a high-impact zone with pollution concerns. Plasticisers in extracted MPs and HMs adsorption on MPs surface from surrounding waters reveal their roles as a source and vector for contaminants, respectively. The mean concentration of metoprolol (53.7-306 ng L-1), tramadol (16.6-198 ng L-1), venlafaxine (24.6-234 ng L-1), and triclosan (211-433 ng L-1) in Maharashtra's coastal waters were several folds higher than in other water systems, raising major health concerns. The hazard quotient (HQ) scores revealed that >70 % of study sites pose a high to medium (1 > HQ > 0.1) ecological risk to fish, crustaceans and algae, indicating serious concern. Fish and crustaceans (35.3 % each) show a higher level of risk than algae (29.5 %). Metoprolol and venlafaxine could represent greater ecological risks than tramadol. Similarly, HQ suggests that bisphenol A has larger ecological risks than bisphenol S along the Maharashtra coast. To the best of our knowledge, this is the first in-depth investigation into emerging pollutants in Indian coastal regions. This information is crucial for better policy formulation and coastal management in India in general, and Maharashtra in particular.
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Cosméticos , Metales Pesados , Tramadol , Contaminantes Químicos del Agua , Animales , Microplásticos/análisis , Ecosistema , Agua/análisis , Plásticos/análisis , Sedimentos Geológicos , Cromatografía Liquida , Metoprolol , Clorhidrato de Venlafaxina , Contaminantes Químicos del Agua/análisis , India , Espectrometría de Masas en Tándem , Metales Pesados/análisis , Medición de Riesgo , Cosméticos/análisis , Preparaciones Farmacéuticas , Monitoreo del AmbienteRESUMEN
We monitored concentrations of Cd, Cu, Mn and Zn in acantocephalan parasites (Acanthocephalus lucii) and its final host (Perca fluviatilis). The concentrations in parasites were found to be significantly higher than those found in the muscle, gonads and liver of fish host. The bioaccumulation factor values (BF=C(parasite)/C(host muscle)) were 194, 24.4, 2.2 and 4.7 for Cd, Cu, Mn and Zn, respectively. This suggests a benefit for the host due to the high accumulation of toxic cadmium.
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Acantocéfalos/química , Intestinos/parasitología , Metales Pesados/análisis , Percas , Contaminantes Químicos del Agua/análisis , Animales , Cadmio/análisis , Cadmio/farmacocinética , Ciudades , Cobre/análisis , Cobre/farmacocinética , República Checa , Monitoreo del Ambiente , Agua Dulce , Manganeso/análisis , Manganeso/farmacocinética , Metales Pesados/farmacocinética , Percas/metabolismo , Percas/parasitología , Distribución Tisular , Contaminantes Químicos del Agua/farmacocinética , Zinc/análisis , Zinc/farmacocinéticaRESUMEN
Sustainable plastic-waste management is becoming increasingly challenging as enormous loads of plastic debris regularly accumulate in susceptible ecosystems. The microplastic (MP) particles generated from these plastic wastes are imposing additional threats to these ecosystems due to their small size as well as their ability to adsorb and carry toxic chemicals. The current investigation deals with one such MP-originated toxicant, diethyl phthalate (DEP), and its impact on two species of freshwater loaches from the Western Ghats of India, Lepidocephalichthys thermalis and Indoreonectes evezardi. The MP samples were collected from the sediments of the Mula River and characterized using spectroscopic methods and scanning electron microscopy. Polymers, such as polyvinyl chloride and polypropylene, were identified in the collected MPs. GC-MS analysis of the MP extracts revealed the presence of DEP, confirming the MP waste as a potential source of DEP pollution. Further, to evaluate the effect of DEP on survival of selected loaches, L. thermalis and I. evezardi were exposed to DEP concentrations (18.75-300 mg L-1) and the lethal DEP dose (LC50) was estimated to be 44.53 mg L-1 for L. thermalis and 34.64 mg L-1 for I. evezardi. Fishes were further exposed to sub-lethal DEP concentration for one day (Short term exposure: STE) or eight days (Long term exposure: LTE) to analyze the histological condition and oxidative status of the liver in response to DEP treatment. Histology revealed congestion of sinusoids and vacuolization after the LTE. Higher lipid peroxidation levels were also measured in the livers of both species treated with DEP, which indicated DEP-mediated oxidative damage. The antioxidant enzymes including superoxide dismutase, catalase, peroxidase and glutathione-S-transferase displayed elevated activities in response to STE and LTE of DEP. Collectively, the results demonstrate that MPs in the Mula River are a potential source of DEP. The findings also show that DEP exposure can be fatal to freshwater fishes such as loaches, possibly by causing increased oxidative damage to the hepatic system.
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Plastificantes , Contaminantes Químicos del Agua , Animales , Ecosistema , Peces/metabolismo , Glutatión Transferasa/metabolismo , Microplásticos , Estrés Oxidativo/fisiología , Ácidos Ftálicos , Plastificantes/toxicidad , Plásticos , Contaminantes Químicos del Agua/toxicidadRESUMEN
This study focuses on the comparison of three selected modifications of the McMaster counting technique, namely the McMaster method modified by Wetzel (W) and Zajícek (Z), as well as the concentration McMaster technique according to Roepstorff and Nansen (R&N). These modifications differ in the weights of faeces examined (W, 2 g/Z, 1 g/R&N, 4 g), flotation solutions (W, NaCl/Z, MgSO(4) + Na(2)S(2)O(3)/R&N, NaCl + glucose), centrifugation (W, none/Z, 2,000 RPM for 2 min and 2,000 RPM for 1 min/R&N, 1,200 RPM for 5 min), number of McMaster chambers investigated (W, 3/Z, 2/R&N, 2), and multiplication factors used (W, 67/Z, 33/R&N, 20). To investigate the sensitivity and reliability of these methods, nematode eggs (Teladorsagia circumcincta) were used. Parasite elements are distributed through negative binomial distribution in naturally infected host faeces, and the number of parasite elements in a given amount of faeces sample is unknown to man. Therefore, we decided to prepare the exact number of eggs which were added to the parasite negative faeces; the faecal sample was then investigated. From this perspective, this is the first time a comparison of the McMaster methods has been so accurately investigated. This approach allows us to evaluate the real sensitivity and reliability of the tested method. As the findings of this study indicate, the highest sensitivity and reliability were obtained using the Roepstorff and Nansen modification. This McMaster modification is able to detect 20 eggs per sample (in 70% of samples). Concentrations of 200 and 500 eggs can be found in almost 100% of samples. Moreover, this method is simple, cheap and fast. For these reasons, we can recommend this method for routine veterinary practice.
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Heces/parasitología , Recuento de Huevos de Parásitos/métodos , Trichostrongyloidea/aislamiento & purificación , Animales , Sensibilidad y Especificidad , OvinosRESUMEN
Lead concentrations in the tissues of perch and its parasites were determined as mg/kg dw. Lead was found at higher concentrations in the acanthocephalans (11.56) than in different tissues (liver, gonads and muscle with skin and bone) of perch. With respect to fish tissues, the highest concentrations of lead were present in the liver (1.24), followed by the gonads (0.57) whereas the lowest concentrations were in the muscle with skin and bone (0.21). The bioconcentration factors for lead indicated that parasites accumulate metals to a higher degree than fish tissues--lead concentrations in acanthocephalans were 9.32, 19.27 and 55.05 higher than in liver, gonads and muscles of host, respectively.
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Acantocéfalos/metabolismo , Plomo/metabolismo , Percas/metabolismo , Ríos/química , Contaminantes Químicos del Agua/metabolismo , Acantocéfalos/aislamiento & purificación , Animales , Huesos/metabolismo , República Checa , Monitoreo del Ambiente/métodos , Gónadas/metabolismo , Plomo/análisis , Hígado/metabolismo , Músculos/metabolismo , Percas/parasitología , Piel/metabolismo , Contaminantes Químicos del Agua/análisisRESUMEN
A desirable attribute of novel antimicrobial agents for bacterial diarrhea is decreased toxicity toward host intestinal microbiota. In addition, gut dysbiosis is associated with an increased risk of developing intestinal cancer. In this study, the selective growth-inhibitory activities of ten phytochemicals and their synthetic analogs (berberine, bismuth subsalicylate, ferron, 8-hydroxyquinoline, chloroxine, nitroxoline, salicylic acid, sanguinarine, tannic acid, and zinc pyrithione), as well as those of six commercial antibiotics (ceftriaxone, ciprofloxacin, chloramphenicol, metronidazole, tetracycline, and vancomycin) against 21 intestinal pathogenic/probiotic (e.g., Salmonella spp. and bifidobacteria) bacterial strains and three intestinal cancer/normal (Caco-2, HT29, and FHs 74 Int) cell lines were examined in vitro using the broth microdilution method and thiazolyl blue tetrazolium bromide assay. Chloroxine, ciprofloxacin, nitroxoline, tetracycline, and zinc pyrithione exhibited the most potent selective growth-inhibitory activity against pathogens, whereas 8-hydroxyquinoline, chloroxine, nitroxoline, sanguinarine, and zinc pyrithione exhibited the highest cytotoxic activity against cancer cells. None of the tested antibiotics were cytotoxic to normal cells, whereas 8-hydroxyquinoline and sanguinarine exhibited selective antiproliferative activity against cancer cells. These findings indicate that 8-hydroxyquinoline alkaloids and metal-pyridine derivative complexes are chemical structures derived from plants with potential bioactive properties in terms of selective antibacterial and anticancer activities against diarrheagenic bacteria and intestinal cancer cells.
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Total mercury concentrations were determined in the gonadal tissues of 15 female and 10 male European perch (Perca fluviatilis) from one location of the stream "Jevanský potok" located about 30 km from Prague (Czech Republic). Tissue samples were frozen at -26 °C in polypropylene containers until further processing, which was carried out using an Advance Mercury Analyser (single purpose atomic absorption spectrometer). Mercury concentrations were present in all analysed gonad samples, and ranged from 2.3 to 12.7 µg/kg wet weight. However, we determined a mean Hg concentration (9.45 µg/kg) in male gonads that was 2.4 times greater than that of female gonads (3.9 µg/kg). This is an important finding when taking into account fish sex in environmental pollution monitoring (especially for mercury contamination).
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Monitoreo del Ambiente/métodos , Peces/fisiología , Gónadas/metabolismo , Mercurio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , República Checa , Femenino , Masculino , Mercurio/toxicidad , Ríos/química , Factores Sexuales , Contaminantes Químicos del Agua/toxicidadRESUMEN
The headwaters of five large African river basins flow through the Bié Plateau in Angola and still remain faunistically largely unexplored. We investigated fish fauna from the Cuanza and Okavango-Zambezi river systems from central Angola. We reconstructed molecular phylogenies of the most common cichlid species from the region, Tilapia sparrmanii and Serranochromis macrocephalus, using both mitochondrial and nuclear markers. We found evidence for ichthyofaunal contact and gene flow between the Cuanza and Okavango-Zambezi watersheds in the Bié Plateau in central Angola. Waterfalls and rapids also appeared to restrict genetic exchange among populations within the Cuanza basin. Further, we found that the Angolan Serranochromis cichlid fishes represent a monophyletic lineage with respect to other haplochromines, including the serranochromines from the Congo and Zambezi rivers. This study represents an important initial step in a biodiversity survey of this extremely poorly explored region, as well as giving further understanding to species distributions and gene flow both between and within river basins.
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Cíclidos/genética , Ríos , Angola , Animales , Cíclidos/clasificación , ADN Mitocondrial , Evolución Molecular , Datos de Secuencia Molecular , Filogenia , FilogeografíaRESUMEN
Two tracer tests were conducted between August 2004 and March 2007 at an ecological farm in western Bohemia. The first tracer test was performed for the summer-autumn grazing period (onset of arrested development), the second for spring (resumption of arrested development). In the first tracer test, the percentage of nematodes arresting development over the winter months reached 87.7% for Teladorsagia circumcincta, 66.7% for Haemonchus contortus, 89.9% for Nematodirus filicollis, 21.6% for Trichostrongylus axei, and 23.9% for both Trichostrongylus vitrinus and Trichostrongylus colubriformis. None of the arrested larvae were observed with species Cooperia curticei, Nematodirus battus, and Oesophagostomum venulosum. In the second tracer test, a significant increase of adult worms was discovered in March of species T. circumcincta and N. filicollis and Trichostrongylus spp. in February. Redundancy analysis and generalized linear models analyses have confirmed that environmental conditions play a crucial role in hypobiosis of sheep strongyles in the Czech Republic. The analysis of influences of various environmental factors revealed that the number of arrested larvae was negatively influenced by light-day length, sunshine, or daylight decrease (p < 0.01).