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Seasonal and annual variations in the pollination efficiency of a pollinator community of Dictamnus albus L.
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A. Fisogni M. Rossi F. Sgolastra L. Bortolotti G. Bogo N. de Manincor M. Quaranta M. Galloni 《Plant biology (Stuttgart, Germany)》2016,18(3):445-454
The interplay between insect and plant traits outlines the patterns of pollen transfer and the subsequent plant reproductive fitness. We studied the factors that affect the pollination efficiency of a pollinator community of Dictamnus albus L. by evaluating insect behaviour and morphological characteristics in relation to flowering phenology. In order to extrapolate the pollinator importance of single taxa and of the whole pollinator guild, we calculated an index distinguishing between potential (PPI) and realized (RPI) pollinator importance. Although the pollinator species spectrum appeared rather constant, we found high intra‐ and inter‐annual variability of pollinator frequency and importance within the insect community. Flower visitation rate strictly depended on insect abundance and on the overlap between their flying period and flower blooming. All the pollinators visited flowers from the bottom to the top of the racemes, excluding intra‐plant geitonogamous pollination, and most of them showed high pollen fidelity. Only medium large‐sized bees could contact the upward bending stiles while feeding on nectar, highlighting a specialisation of the plant towards bigger pollinators. Moreover, we found evidence of functional specialisation, since all pollinators were restricted to a single taxonomic group (order: Hymenoptera; superfamily: Apoidea). Both the PPI and RPI indices indicate Habropoda tarsata as the most important pollinator of D. albus. Following hand cross‐pollination experiments we revealed the presence of pollination limitation in 1 of the 3 years of field study. We discuss this result in relation to flowering abundance and to possible mismatches of phenological periods between plants and insects. 相似文献
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Juliane Ventura-Lima Micheli Rosa de Castro Daiane Acosta Daniele Fattorini Francesco Regoli Leandro Machado de Carvalho Denise Bohrer Laura A. Geracitano Daniela Martí Barros Luis F.F. Marins Rosane Souza da Silva Carla Denise Bonan Maurício Reis Bogo José M. Monserrat 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2009,149(4):538-543
In fishes, arsenic (As) is absorbed via the gills and is capable of causing disturbance to the antioxidant system. The objective of present study was to evaluate antioxidant responses after As exposure in gills of zebrafish (Danio rerio, Cyprinidae). Fish were exposed for 48 h to three concentration of As, including the highest As concentration allowed by current Brazilian legislation (10 μg As/L). A control group was exposed to tap water (pH 8.0; 26 °C; 7.20 mg O2/L). As exposure resulted in (1) an increase (p < 0.05) of glutathione (GSH) levels after exposure to 10 and 100 μg As/L, (2) an increase of the glutamate cysteine ligase (GCL) activity in the same concentrations (p < 0.05), (3) no significant differences in terms of glutathione reductase, glutathione-S-transferase and catalase activities; (4) a significantly lower (p < 0.05) oxygen consumption after exposure to 100 μg As/L; (4) no differences in terms of oxygen reactive species generation and lipid peroxidation content (p > 0,05). In the gills, only inorganic As was detected. Overall, it can be concluded that As affected the antioxidant responses increasing GCL activity and GSH levels, even at concentration considered safe by Brazilian legislation. 相似文献
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Luisa Azambuja Alcalde Betânia Souza de Freitas Gustavo Dalto Barroso Machado Pedro Castilhos de Freitas Crivelaro Victoria Campos Dornelles Henrique Gus Ricardo Tavares Monteiro Luiza Wilges Kist Mauricio Reis Bogo Nadja Schröder 《Biometals》2018,31(6):927-940
Brain-derived neurotrophic factor (BDNF) plays a key role in neural development and physiology, as well as in pathological states. Post-mortem studies demonstrate that BDNF is reduced in the brains of patients affected by neurodegenerative diseases. Iron accumulation has also been associated to the pathogenesis of neurodegenerative diseases. In rats, iron overload induces persistent memory deficits, increases oxidative stress and apoptotic markers, and decreases the expression of the synaptic marker, synaptophysin. Deferiprone (DFP) is an oral iron chelator used for the treatment of systemic iron overload disorders, and has recently been tested for Parkinson’s disease. Here, we investigated the effects of iron overload on BDNF levels and on mRNA expression of genes encoding TrkB, p75NTR, catalase (CAT) and NQO1. We also aimed at investigating the effects of DFP on iron-induced impairments. Rats received iron or vehicle at postnatal days 12–14 and when adults, received chronic DFP or water (vehicle). Recognition memory was tested 19 days after the beginning of chelation therapy. BDNF measurements and expression analyses in the hippocampus were performed 24 h after the last day of DFP treatment. DFP restored memory and increased hippocampal BDNF levels, ameliorating iron-induced effects. Iron overload in the neonatal period reduced, while treatment with DFP was able to rescue, the expression of antioxidant enzymes CAT and NQO1. 相似文献
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Nadine Glesse Paula Rohr Odirlei André Monticielo Tássia Flores Rech João Carlos Tavares Brenol Ricardo Machado Xavier Kátia Kvitko José Artur Bogo Chies 《Molecular biology reports》2014,41(9):6167-6179
Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease that presents several clinical manifestations, affecting multiple organs and systems. Immunological, environmental, hormonal and genetic factors may contribute to disease. Genes and proteins involved in metabolism and detoxification of xenobiotics are often used as susceptibility markers to diseases with environmental risk factors. Cytochrome P450 (CYP) enzymes activate the xenobiotic making it more reactive, while the Glutathione S-transferases (GST) enzymes conjugate the reduced glutathione with electrophilic compounds, facilitating the toxic products excretion. CYP and GST polymorphisms can alter the expression and catalytic activity of enzymes. This study aimed to investigate the role of genetic variants of CYP and GST in susceptibility and clinical expression of SLE, through the analysis of GSTM1 null, GSTT1 null, GSTP1*Ile105Val, CYP1A1*2C and CYP2E1*5B polymorphisms. 371 SLE patients from Hospital de Clínicas de Porto Alegre and 522 healthy blood donors from southern Brazil were evaluated. GSTP1 and CYP variants were genotyped using PCR–RFLP and GSTT1 and GSTM1 variants were analyzed by multiplex PCR. Among European-derived individuals, a lower frequency of GSTP1*Val heterozygous genotypes was found in SLE patients when compared to controls (p = 0.005). In African-derived SLE patients, the CYP2E1*5B allelic frequency was higher in relation to controls (p = 0.054). We did not observe any clinical implication of the CYP and GST polymorphisms in patients with SLE. Our data suggest a protective role of the GSTP1*Ile/Val heterozygous genotype against the SLE in European-derived and a possible influence of the CYP2E1*5B allele in SLE susceptibility among African-derived individuals. 相似文献
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Vanessa Kappel da Silva Betânia Souza de Freitas Arethuza da Silva Dornelles Laura Roesler Nery Lucio Falavigna Rafael Dal Ponte Ferreira Maurício Reis Bogo Jaime Eduardo Cecílio Hallak Antônio Waldo Zuardi José Alexandre S. Crippa Nadja Schröder 《Molecular neurobiology》2014,49(1):222-233
We have recently shown that chronic treatment with cannabidiol (CBD) was able to recover memory deficits induced by brain iron loading in a dose-dependent manner in rats. Brain iron accumulation is implicated in the pathogenesis of neurodegenerative diseases, including Parkinson’s and Alzheimer’s, and has been related to cognitive deficits in animals and human subjects. Deficits in synaptic energy supply have been linked to neurodegenerative diseases, evidencing the key role played by mitochondria in maintaining viable neural cells and functional circuits. It has also been shown that brains of patients suffering from neurodegenerative diseases have increased expression of apoptosisrelated proteins and specific DNA fragmentation. Here, we have analyzed the expression level of brain proteins involved with mitochondrial fusion and fission mechanisms (DNM1L and OPA1), the main integral transmembrane protein of synaptic vesicles (synaptophysin), and caspase 3, an apoptosis-related protein, to gain a better understanding of the potential of CBD in restoring the damage caused by iron loading in rats. We found that CBD rescued iron-induced effects, bringing hippocampal DNM1L, caspase 3, and synaptophysin levels back to values comparable to the control group. Our results suggest that iron affects mitochondrial dynamics, possibly trigging synaptic loss and apoptotic cell death and indicate that CBD should be considered as a potential molecule with memory-rescuing and neuroprotective properties to be used in the treatment of cognitive deficits observed in neurodegenerative disorders. 相似文献
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Nucleotides and nucleosides play an important role in neurodevelopment acting through specific receptors. Ectonucleotidases
are the major enzymes involved in controlling the availability of purinergic receptors ligands. ATP is co-released with several
neurotransmitters and is the most important source of extracellular adenosine by catabolism exerted by ectonucleotidases.
The main ectonucleotidases are named NTPDases (1–8) and 5′-nucleotidase. Adenosine is a powerful modulator of neurotransmitter
release. Caffeine blocks adenosine receptor activity as well as adenosine-mediated neuromodulation. Considering the susceptibility
of the immature brain to caffeine and the need for correct purinergic signaling during fetal development, we have analyzed
the effects of caffeine exposure during gestational and lactational periods on nucleotide degradation and ectonucleotidase
expression from the hippocampi of 7-, 14- and 21-days-old rats. Nucleotides hydrolysis was assessed by colorimetric determination
of inorganic phosphate released. Ectonucleotidases expression was performed by RT-PCR. ATP and ADP hydrolysis displayed parallel
age-dependent decreases in both control and caffeine-treated groups. AMP hydrolysis increased with caffeine treatment in 7-days-old
rats (75%); although there was no significant difference in AMP hydrolysis between control (non caffeine-treated) rats and
14- or 21-days caffeine-treated rats. ADP hydrolysis was not affected by caffeine treatment. Caffeine treatment in 7- and
14-days-old rats decreased ATP hydrolysis when compared to the control group (19% and 60% decrease, respectively), but 21-days-treated
rats showed an increase in ATP hydrolysis (39%). Expression levels of NTPDase 1 and 5 decreased in hippocampi of caffeine-treated
rats. The expression of 5′-nucleotidase was not affected after caffeine exposure. The changes observed in nucleotide hydrolysis
and ectonucleotidases expression could promote subtle effects on normal neural development considering the neuromodulatory
role of adenosine. 相似文献
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Alessandro Fisogni Marino Quaranta Francesca-Vittoria Grillenzoni Francesca Corvucci Natasha de Manincor Gherardo Bogo Laura Bortolotti Marta Galloni 《Arthropod-Plant Interactions》2018,12(2):191-200
Bees collect pollen as an important resource for offspring development while acting as pollen vectors for the plants visited. Foraging preferences of pollinators together with plant species availability shape the web of interactions at the local scale. In this study, we focused on the bee pollinator community of a population of the rare protected perennial herb Dictamnus albus, with the aim to characterise the pollen preferences and the foraging niche overlap among species through time. Bees were sampled during four consecutive years in a natural population of D. albus, throughout the blooming period of the plant species. We performed an analysis of insect pollen loads to investigate the interactions with the study species and the co-flowering plants in the area, and to evaluate the degree of foraging overlap among pollinators. Over the study years, all bee species showed a high fidelity to D. albus (60–80%), even if some taxa preferentially collected pollen from other flowering species. The foraging niche overlap in the pollinator community decreased together with an increased diversity of co-flowering plant species. The results obtained indicate that bees preferentially forage on D. albus in the studied area, but that co-flowering species contribute to complement their diet and likely reduce competition for foraging resources. It appears therefore important to maintain a high diversity of co-flowering plants to preserve the diversity in the studied pollinator community of D. albus. 相似文献
9.
V Bogo 《Radiation research》1984,100(2):313-320
Relatively high, rapidly delivered doses of ionizing radiation have been reported to produce an immediate decrement in performance (PD) in a number of animal species. This study investigated the effects of bremsstrahlung and electron radiation on the performance of rats unilaterally exposed by a linear accelerator (LINAC facility) at a midline tissue dose rate of 2000 rad/min. Relative radiation effects were determined by establishing median effective doses (ED50) for rats trained on the accelerod, which is a shock-avoidance test of motor performance. The ED50s were based on 10-min postexposure performance. Subjects were also tested at 15, 30, 60, and 120 min and 24 hr after exposure. Fifty-seven trained rats were exposed to bremsstrahlung radiation, and 40 trained rats were exposed to electrons. The ED50 was 8121 rad for the bremsstrahlung field and 6110 rad for the electron field, for a significantly different relative effectiveness of the electron field in producing PD of 1.35. The data imply that different radiation fields are not equally effective in producing PD. 相似文献
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High frequency gene conversion among benomyl resistant transformants in the entomopathogenic fungus Metarhizium anisopliae 总被引:4,自引:0,他引:4
Maurício Reis Bogo Marilene Henning Vainstein francisco JoséLima Aragão Elíbio Rech Augusto Schrank 《FEMS microbiology letters》1996,142(1):123-127
Abstract Three different methods, (i) PEG, (ii) electroporation and (iii) biolistic, were employed to transform Metarhizium anisopliae using benomyl resistance as a selectable marker. Transformation frequencies and mitotic stability varied for each method, from 0.8 to 6.9 transformants μg−1 of DNA and 46%, respectively, by the PEG method; 1.3 to 1.8 transformants μg−1 of DNA and 67% by electroporation; and 32 to 201 transformants μg−1 of DNA and 90% by biolistic. We demonstrate by PCR that 60% of the transformants were generated by gene conversion. 相似文献