host-shift
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Myxobolus pseudodispar Gorbunova, 1936 (Myxozoa) is capable of infecting and developing mature myxospores in several cyprinid species. However, M. pseudodispar isolates from different fish show up to 5% differences in the SSU rDNA sequences. This is an unusually large intraspecific difference for myxozoans and only some of the muscle-dwelling myxozoan species possess such a high genetic variability. We intended to study the correlation between the host specificity and the phylogenetic relationship of the parasite isolates, and to find experimental proof for the putatively wide host range of M. pseudodispar with cross-infection experiments and phylogenetic analyses based on SSU rDNA. The experimental findings distinguished 'primary' and less-susceptible 'secondary' hosts. With some exceptions, M. pseudodispar isolates showed a tendency to cluster according to the fish host on the phylogenetic tree. Experimental and phylogenetic findings suggest the cryptic nature of the species. It is likely that host-shift occurred for M. pseudodispar and the parasite speciation in progress might explain the high genetic diversity among isolates which are morphologically indistinguishable.
Discovering cryptic species in well-studied areas and taxonomic groups can have profound implications in understanding eco-evolutionary processes and in nature conservation because such groups often involve research models and act as flagship taxa for nature management. In this study, we use an array of techniques to study the butterflies in the Spialia sertorius species group (Lepidoptera, Hesperiidae). The integration of genetic, chemical, cytogenetic, morphological, ecological and microbiological data indicates that the sertorius species complex includes at least five species that differentiated during the last three million years. As a result, we propose the restitution of the species status for two taxa often treated as subspecies, Spialia ali (Oberthür, 1881) stat. rest. and Spialia therapne (Rambur, 1832) stat. rest., and describe a new cryptic species Spialia rosae Hernández-Roldán, Dapporto, Dincă, Vicente & Vila sp. nov. Spialia sertorius (Hoffmannsegg, 1804) and S. rosae are sympatric and synmorphic, but show constant differences in mitochondrial DNA, chemical profiles and ecology, suggesting that S. rosae represents a case of ecological speciation involving larval host plant and altitudinal shift, and apparently associated with Wolbachia infection. This study exemplifies how a multidisciplinary approach can reveal elusive cases of hidden diversity.
- MeSH
- fylogeneze * MeSH
- larva MeSH
- mitochondriální DNA genetika MeSH
- motýli klasifikace MeSH
- nadmořská výška MeSH
- vznik druhů (genetika) * MeSH
- Wolbachia MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- severní Afrika MeSH
- východní Evropa MeSH
Eois is one of the best-investigated genera of tropical moths. Its close association with Piper plants has inspired numerous studies on life histories, phylogeny and evolutionary biology. This study provides an updated view on phylogeny, host plant use and temporal patterns of speciation in Eois. Using sequence data (2776 bp) from one mitochondrial (COI) and one nuclear gene (Ef1-alpha) for 221 Eois species, we confirm and reinforce previous findings regarding temporal patterns of diversification. Deep diversification within Andean Eois took place in the Miocene followed by a sustained high rate of diversification until the Pleistocene when a pronounced slowdown of speciation is evident. In South America, Eois diversification is very likely to be primarily driven by the Andean uplift which occurred concurrently with the entire evolutionary history of Eois. A massively expanded dataset enabled an in-depth look into the phylogenetic signal contained in host plant usage. This revealed several independent shifts from Piper to other host plant genera and families. Seven shifts to Peperomia, the sister genus of Piper were detected, indicating that the shift to Peperomia was an easy one compared to the singular shifts to the Chloranthaceae, Siparunaceae and the Piperacean genus Manekia. The potential for close co-evolution of Eois with Piper host plants is therefore bound to be limited to smaller subsets within Neotropical Eois instead of a frequently proposed genus-wide co-evolutionary scenario. In regards to Eois systematics we confirm the monophyly of Neotropical Eois in relation to their Old World counterparts. A tentative biogeographical hypothesis is presented suggesting that Eois originated in tropical Asia and subsequently colonized the Neotropics and Africa. Within Neotropical Eois we were able to identify the existence of six clades not recognized in previous studies and confirm and reinforce the monophyly of all 9 previously delimited infrageneric clades.
- MeSH
- DNA genetika MeSH
- druhová specificita MeSH
- fylogeneze * MeSH
- můry klasifikace genetika MeSH
- respirační komplex IV genetika MeSH
- rostliny * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Jižní Amerika MeSH
The ectoparasitoid wasp, Nasonia vitripennis can enhance its cold tolerance by exploiting a maternally-induced larval diapause. A simple manipulation of the fly host diapause status and supplementation of the host diet with proline also dramatically increase cold tolerance in the parasitoid. In this study, we used a metabolomics approach to define alterations in metabolite profiles of N. vitripennis caused by diapause in the parasitoid, diapause of the host, and augmentation of the host's diet with proline. Metabolic profiles of diapausing and nondiapausing parasitoid were significantly differentiated, with pronounced distinctions in levels of multiple cryoprotectants, amino acids, and carbohydrates. The dynamic nature of diapause was underscored by a shift in the wasp's metabolomic profile as the duration of diapause increased, a feature especially evident for increased concentrations of a suite of cryoprotectants. Metabolic pathways involved in amino acid and carbohydrate metabolism were distinctly enriched during diapause in the parasitoid. Host diapause status also elicited a pronounced effect on metabolic signatures of the parasitoid, noted by higher cryoprotectants and elevated compounds derived from glycolysis. Proline supplementation of the host diet did not translate directly into elevated proline in the parasitoid but resulted in an alteration in the abundance of many other metabolites, including elevated concentrations of essential amino acids, and reduction in metabolites linked to energy utilization, lipid and amino acid metabolism. Thus, the enhanced cold tolerance of N. vitripennis associated with proline augmentation of the host diet appears to be an indirect effect caused by the metabolic perturbations associated with diet supplementation.
- MeSH
- diapauza hmyzu fyziologie MeSH
- dieta MeSH
- glykolýza MeSH
- larva růst a vývoj metabolismus MeSH
- metabolom MeSH
- nízká teplota MeSH
- prolin aplikace a dávkování MeSH
- Sarcophagidae metabolismus parazitologie MeSH
- sršňovití růst a vývoj metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Current knowledge about polysphinctine parasite wasps' interactions with their spider hosts is very fragmented and incomplete. This study presents the host specificity of Zatypota percontatoria (Müller) (Hymenoptera: Ichneumonidae) and its adaptation to varying host availability. Two years of field observations show that Z. percontatoria is a stenophagous parasitoid that parasitizes only five closely related web-building spiders of the family Theridiidae (Araneae). Within the Theridiidae it attacks only species belonging to a small group of species, here called the "Theridion" group. These hosts have a similar biology, but are available at different levels of abundance and at different sizes over the season. Laboratory experiments showed that this wasp species ignores linyphiid, araneid or dictynid spiders and accepts only theridiid spiders of the "Theridion" group. In the field study, wasp females preferred older juvenile and sub-adult female spider instars with intermediate body size. Only 5% of the parasitized spiders were males. Parasitism in the natural population of theridiid spiders was on average 1.3%. Parasitism was most frequent on two species, Theridion varians Hahn in 2007 and Neottiura bimaculata Linnaeus in 2008. The parasitization rate was positively correlated with spider abundance. The wasp responded adaptively to seasonal changes in host abundance and host body size and shifted host preference according to the availability of suitable hosts during, as well as between, seasons. In spring and summer the highest percentage of parasitism was on T. varians and in autumn it was on N. bimaculata.
Few cases of spontaneously horizontally transferred bacterial genes into plant genomes have been described to date. The occurrence of horizontally transferred genes from the T-DNA of Agrobacterium rhizogenes into the plant genome has been reported in the genus Nicotiana and in the species Linaria vulgaris. Here we compare patterns of evolution in one of these genes (a gene encoding mikimopine synthase, mis) following three different events of horizontal gene transfer (HGT). As this gene plays an important role in Agrobacterium, and there are known cases showing that genes from pathogens can acquire plant protection function, we hypothesised that in at least some of the studied species we will find signs of selective pressures influencing mis sequence. The mikimopine synthase (mis) gene evolved in a different manner in the branch leading to Nicotiana tabacum and N. tomentosiformis, in the branch leading to N. glauca and in the genus Linaria. Our analyses of the genus Linaria suggest that the mis gene began to degenerate soon after the HGT. In contrast, in the case of N. glauca, the mis gene evolved under significant selective pressures. This suggests a possible role of mikimopine synthase in current N. glauca and its ancestor(s). In N. tabacum and N. tomentosiformis, the mis gene has a common frameshift mutation that disrupted its open reading frame. Interestingly, our results suggest that in spite of the frameshift, the mis gene could evolve under selective pressures. This sequence may still have some regulatory role at the RNA level as suggested by coverage of this sequence by small RNAs in N. tabacum.
- MeSH
- Agrobacterium enzymologie genetika MeSH
- bakteriální proteiny klasifikace genetika metabolismus MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- imidazoly metabolismus MeSH
- interakce hostitele a patogenu genetika MeSH
- Linaria genetika mikrobiologie MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- oxidoreduktasy působící na CH-NH vazby klasifikace genetika metabolismus MeSH
- posunová mutace MeSH
- přenos genů horizontální * MeSH
- pyridiny metabolismus MeSH
- regulace genové exprese enzymů MeSH
- sekvence nukleotidů MeSH
- selekce (genetika) MeSH
- tabák klasifikace genetika mikrobiologie MeSH
- transformace genetická MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- isavukonazol,
- MeSH
- amfotericin B aplikace a dávkování MeSH
- antibakteriální látky terapeutické užití MeSH
- antifungální látky aplikace a dávkování škodlivé účinky MeSH
- imunokompromitovaný pacient MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mukormykóza * chirurgie diagnostické zobrazování farmakoterapie patologie MeSH
- nemoci orbity * chirurgie diagnostické zobrazování farmakoterapie patologie MeSH
- progrese nemoci MeSH
- renální insuficience chemicky indukované MeSH
- senioři MeSH
- triazoly aplikace a dávkování škodlivé účinky MeSH
- záchranná terapie metody MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
- práce podpořená grantem MeSH
OBJECTIVES: The aim of the present study was to evaluate morphological MRI findings in histologically-proven central nervous system lymphoma (CNSL) at time of their first appearance, and to describe dynamic changes on repeat MRI before the diagnosis was histologically proven. METHODS: We retrospectively evaluated the MRI examinations of 74 patients with histologically-proven CNSL (10 secondary CNSL, 64 primary PCNSL; 10 immunocompromised, 54 immunocompetent). In 43 patients, we evaluated the evolution of CNSL on MRI before the diagnosis was proven. RESULTS: Primary CNSL was typically localized supratentorially (63%), with multiple (59%) or infiltrative (36%) lesions showing diffusion restriction (98%), often (87%) reaching the brain surface. In approximately 50% of patients, meningeal, ependymal or cranial nerve involvement was found. We detected significant differences in enhancement patterns between immunocompromised and immunocompetent patients; non-homogenous enhancement present in 50% of immunocompromised patients. We did not find any significant differences in MRI appearance between primary and secondary CNSL. Regression was evident after corticosteroid treatment in 52% of patients; however, in 16% of cases overall progression was observed. CONCLUSION: CNSL generally presents as an infiltrative lesion or multiple homogenously-enhancing lesions of the brain in contact with the brain surface. Involvement of the corpus callosum, cranial nerves, ependyma or meninges is common. No significant differences between primary and secondary CNSL were detected, however differences in enhancement type between immunocompromised and immunocompetent primary CNSL patients were found. We stress the variability of MRI findings in the course of the disease and also the variable response to corticotherapy.
- MeSH
- difuzní magnetická rezonance MeSH
- difúzní velkobuněčný B-lymfom diagnostické zobrazování farmakoterapie imunologie MeSH
- dospělí MeSH
- hormony kůry nadledvin terapeutické užití MeSH
- imunokompetence imunologie MeSH
- imunokompromitovaný pacient imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymfom diagnostické zobrazování farmakoterapie imunologie MeSH
- magnetická rezonanční tomografie MeSH
- mladý dospělý MeSH
- nádory centrálního nervového systému diagnostické zobrazování farmakoterapie imunologie MeSH
- nádory mozku diagnostické zobrazování farmakoterapie imunologie MeSH
- progrese nemoci MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Influenza viruses compared to other viruses are characterized by considerable genetic variability. From the view of the ability of the virus to infect the host cell the determining factor is the structure of the surface antigens of the virus and the host cell receptor structure. To change the preferential binding of the virus to various cell receptors just one amino acid substitution in the primary structure of hemagglutinin is enough. The cause of this change in the antigenic properties is either the antigenic shift or antigenic shift. Thereby, new influenza strains with new antigenic type can develop very quickly and a human population is not capable to immunologically distinguished it with sufficient speed. Yet widely used drugs are increasingly perceived as controversial, due to their declining benefits and vice versa to growing negative effects. And despite considerable progress in the research of influenza viruses and their receptors at the molecular and structural level no sufficiently effective alternative has not been introduced yet.
- MeSH
- antigenní variace MeSH
- antivirové látky farmakologie MeSH
- chřipka lidská * MeSH
- hemaglutininové glykoproteiny viru chřipky MeSH
- hemaglutininy virové * MeSH
- kyseliny sialové * MeSH
- lidé MeSH
- virové receptory MeSH
- virus chřipky A patogenita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
