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991.
Cunha C Ignacio D Coelho MM 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2008,363(1505):2921-2929
Polyploidy, hybridization and variation in mating systems are central issues for a deeper understanding of animal evolution. The Iberian species Squalius alburnoides represents an example combining all three phenomena. Previous studies showed that S. alburnoides populations are mainly composed of triploid and diploid hybrid forms (mainly females), and that the tetraploid forms are rare or absent. Both populations from the Douro drainage reveal a distinct scenario: tetraploid individuals represent 85.6-97.5% of the population, with no sex ratio bias observed. Based on the flow cytometry measurements of blood and spermatozoa cells, microsatellite loci and experimental crosses, we describe here, for the first time, two symmetric allotetraploid populations (CCAA) that resumed normal meiosis after undergoing intermediate processes of non-sexual reproduction to give rise to a new sexually reproducing polyploid species. Prezygotic (habitat selection and assortative mating) and postzygotic mechanisms (nonviable embryos) are responsible for the reproductive isolation from other forms of the S. alburnoides complex (e.g. CA, CAA). This example illustrates how hybrid polyploid complexes may lead to speciation. 相似文献
992.
A.G. Neto A.A. da Silva Filho J.M.L.C. Costa A.H.C Vinholis G.H.B. Souza W.R. Cunha M.L.A.E. Silva S. Albuquerque J.K. Bastos 《Phytomedicine》2004,11(7-8):662-665
Three different concentrations (1, 10 and 50 μg/ml) of lyophilized hydroalcoholic crude extract of Pfaffia glomerata roots were assayed in vitro against strains of Trypanosoma cruzi (Y) and Leishmania braziliensis. It was observed that P. glomerata hydroalcoholic extract was relatively active within the tested concentrations for L. (V.) braziliensis, but inactive against T. cruzi. Despite the fact that both protozoans belong to the Trypanosomatidae family, we suggest that the difference observed for activity should be related to the biological differences between the two parasite species. 相似文献
993.
The connective tissue index of <Emphasis Type="Italic">Helix aspersa</Emphasis> as a metal biomarker
André Filipe Santos Amaral Henrique Anselmo Regina Maria Pires Toste Tristão da Cunha Armindo Santos Rodrigues 《Biometals》2004,17(6):625-629
The digestive gland of adult land snails, Helix aspersa, sampled from four different sites in São Miguel island (Azores) was submitted to chemical analyses, autometallography and haemalum/eosin staining, in order to quantify the relative abundance of heavy metals, calcium cells and connective tissue cells. Metals were visualized, through light microscopy, as black silver deposits mostly in the connective tissue cells. Metal levels, essentially of Cu and Fe, were related to the relative volumetric density of connective tissue cells but not to the relative volumetric density of calcium cells from the digestive gland epithelium. Thus, the connective tissue index presented herein is suggested as a biomarker of Cu exposure in terrestrial mollusks. 相似文献
994.
995.
Basílio AC de Araújo PR de Morais JO da Silva Filho EA de Morais MA Simões DA 《Current microbiology》2008,56(4):322-326
Monitoring for wild yeast contaminants is an essential component of the management of the industrial fuel ethanol manufacturing
process. Here we describe the isolation and molecular identification of 24 yeast species present in bioethanol distilleries
in northeast Brazil that use sugar cane juice or cane molasses as feeding substrate. Most of the yeast species could be identified
readily from their unique amplification-specific polymerase chain reaction (PCR) fingerprint. Yeast of the species Dekkera bruxellensis, Candida tropicalis, Pichia galeiformis, as well as a species of Candida that belongs to the C. intermedia clade, were found to be involved in acute contamination episodes; the remaining 20 species were classified as adventitious.
Additional physiologic data confirmed that the presence of these major contaminants cause decreased bioethanol yield. We conclude
that PCR fingerprinting can be used in an industrial setting to monitor yeast population dynamics to early identify the presence
of the most important contaminant yeasts. 相似文献
996.
Claudia Maria Lincoln Silva Fred Bernardes Filho Glauber Voltan Jaci Maria Santana Marcel Nani Leite Filipe Rocha Lima Luisiane de Avila Santana Natlia Aparecida de Paula Patricia Toscano Barreto Nogueira Onofre Wilson Marques-Junior Vanessa Aparecida Tomaz Carmem Sílvia Vilela Pinese Marco Andrey Cipriani Frade 《PLoS neglected tropical diseases》2021,15(8)
997.
I. Camargo Filho D.A.G. Cortez T. Ueda-Nakamura C.V. Nakamura B.P. Dias Filho 《Phytomedicine》2008,15(3):202-208
In this paper, we describe the purification of an antiviral peptide from seeds of Sorghum bicolor L. by a procedure that included gel filtration, ion exchange, and high-performance liquid chromatography (HPLC) in a reversed-phase column. Its molecular weight, determined by chromatographic mobility on the Shim-pack DIOL-150 gel permeation column in HPLC, was found to be 2000 Da. The peptide designated 2 kD peptide strongly inhibited the replication of herpes simplex virus type 1 (HSV-1), dose-dependently, at 40–90% of the control level, after incubation with 10–50 μM of the peptide, with EC50 and EC90 values of 6.25 and 15.25 μM, respectively. The IC50 value of the 2 kD peptide against Vero cells was 250 μM. Pre-incubation of HSV-1 with various concentrations of the 2 kD peptide showed dose-dependent cytopathic effects (CPE) reduction patterns at concentrations from 6.25 to 50 μM. The presence of the 2 kD peptide before HSV-1 infections showed moderate inhibition of virus-induced CPE as compared to during or after infections, with EC50 values of 12.5, 6.25, and 6.25 μM, respectively. Similar results were observed when the 2 kD peptide was assayed against bovine herpes virus (BHV), an enveloped virus like HSV-1. On the other hand, the 2 kD peptide showed weak activity against poliovirus type 1, a non-enveloped virus. Taken together, these results indicate that the 2 kD peptide was able not only to inhibit the initiation and the spread of infection, but also had an in vitro prophylactic effect against HSV-1 infection. 相似文献
998.
A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao
Jorge MC Mondego Marcelo F Carazzolle Gustavo GL Costa Eduardo F Formighieri Lucas P Parizzi Johana Rincones Carolina Cotomacci Dirce M Carraro Anderson F Cunha Helaine Carrer Ramon O Vidal Raíssa C Estrela Odalys García Daniela PT Thomazella Bruno V de Oliveira Acássia BL Pires Carolina S Maria Rio Marcos Renato R Araújo Marcos H de Moraes Luis AB Castro Karina P Gramacho Marilda S Gonçalves José P Moura Neto Aristóteles Góes Neto Luciana V Barbosa Mark J Guiltinan Bryan A Bailey Lyndel W Meinhardt Julio CM Cascardo Gonçalo AG Pereira 《BMC genomics》2008,9(1):1-25
999.
Avilez IM Hori TS de Almeida LC Hackbarth A da Cunha Bastos Neto J da Cunha Bastos VL Moraes G 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2008,148(2):136-142
Parameters of the antioxidant defense systems of Brycon amazonicus (matrinx?--a neotropical fish) exposed to phenol for 96 h plus the recovery over 1 and 2 weeks were studied in erythrocytes and liver. Hematocrit increase was observed during phenol exposure and recovery for 1 week. Total superoxide dismutases (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) did not change during phenol exposure. Erythrocyte glucose-6-phosphate dehydrogenase (G6PDH) increased during that period while catalase (CAT) activity decreased during phenol exposure and recovery for 2 weeks. In the liver, SOD and CAT did not change, whereas GPx increased in the first week of recovery and decreased after 2 weeks. A late response was observed for G6PDH activity which increased only at the second week. Ascorbate concentration in the brain decreased during phenol exposure and increased over recovery. From our results it appears that the oxidative stress was limited in matrinx? exposed to phenol, but seemed to occur during the recovery period. 相似文献
1000.
Zhao S Cunha C Zhang F Liu Q Gloss B Deisseroth K Augustine GJ Feng G 《Brain Cell Biology》2008,36(1-4):141-154
The ability to control and manipulate neuronal activity within an intact mammalian brain is of key importance for mapping functional connectivity and for dissecting the neural circuitry underlying behaviors. We have previously generated transgenic mice that express channelrhodopsin-2 for light-induced activation of neurons and mapping of neural circuits. Here we describe transgenic mice that express halorhodopsin (NpHR), a light-driven chloride pump that can be used to silence neuronal activity via light. Using the Thy-1 promoter to target NpHR expression to neurons, we found that neurons in these mice expressed high levels of NpHR-YFP and that illumination of cortical pyramidal neurons expressing NpHR-YFP led to rapid, reversible photoinhibition of action potential firing in these cells. However, NpHR-YFP expression led to the formation of numerous intracellular blebs, which may disrupt neuronal function. Labeling of various subcellular markers indicated that the blebs arise from retention of NpHR-YFP in the endoplasmic reticulum. By improving the signal peptide sequence and adding an ER export signal to NpHR-YFP, we eliminated the formation of blebs and dramatically increased the membrane expression of NpHR-YFP. Thus, the improved version of NpHR should serve as an excellent tool for neuronal silencing in vitro and in vivo. 相似文献