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1.
Leishmaniasis, a neglected tropical disease, is a major cause of morbidity and mortality worldwide. Of the three main clinical forms, cutaneous leishmaniasis (CL) is the most common and 40 million people are at risk in the endemic areas. Currently, the available drugs to fight leishmaniasis have high toxicity and poor efficiency. Then, it is very important to search for effective and safe drugs that would target essential enzymes from the parasite, such as lanosterol 14-alpha demethylase (CYP51, EC 1.14.13.70) from Leishmania braziliensis. Because most drug design efforts have been directed for Leishmania non-braziliensis species, there is no structural or kinetic data regarding L. braziliensis CYP51. Herein, we present for the first time molecular biology efforts and purification protocol to obtain the enzyme LbCYP51. These results lay the ground for future investigation of drugs against this target.  相似文献   

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Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.  相似文献   

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Three species of cecidomyiid midges (Diptera: Cecidomyiidae), whose larvae overwinter in the soil, can cause significant yield losses on wheat in Europe: the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), the yellow wheat blossom midge, Contarinia tritici (Kirby), and the saddle gall midge, Haplodiplosis marginata (von Roser). The biological control of wheat midges by their parasitoids can contribute to reduce the midge populations. Soil samples were collected in several fields in Belgium in 2012–2014 in order to characterize the parasitism rates and parasitoid complexes in overwintering larvae. The parasitism rates varied greatly between the sampled fields: 3–100, 0–100 and 2% for S. mosellana, H. marginata and C. tritici, respectively. The parasitism rate was not related to the larval density of wheat midge. The three wheat midges have totally distinct parasitoid complexes in Belgium. Eight species (Hymenoptera: Pteromalidae and Platygastridae) were found as parasitoid of S. mosellana: Macroglenes penetrans (Kirby), Amblypasis tritici (Walker), Euxestonotus error (Fitch), Euxestonutus sp. Fouts, Leptacis sp. Foerster, Platygaster gracilipes (Huggert), Platygaster nisus Walker, and Platygaster tuberosula (Kieffer). According to their abundance, M. penetrans, E. error and P. tuberosula appeared as the main parasitoids of S. mosellana in Belgium. For the two other wheat midges, only one species of the family Platygastridae was found for each midge: Platygaster equestris (Spittler) for H. marginata and Synopeas myles (Walker) for C. tritici.  相似文献   

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TC1/Mariner transposons belong to class II transposable elements (TEs) that use DNA-mediated “cut and paste” mechanism to transpose, and they have been identified in almost all organisms. Although silkworm (Bombyx mori) has a large amount of TC1/Mariner elements, the genome wide information of this superfamily in the silkworm is unknown. In this study, we have identified 2670 TC1/Mariner (Bmmar) elements in the silkworm genome. All the TEs were classified into 22 families by means of fgclust, a tool of repetitive sequence classification, seven of which was first reported in this study. Phylogenetic and structure analyses based on the catalytic domain (DDxD/E) of transposase sequences indicated that all members of TC1/Mariner were grouped into five subgroups: Mariner, Tc1, maT, DD40D and DD41D/E. Of these five subgroups, maT rather than Mariner possessed most members of TC1/Mariner (51.23%) in the silkworm genome. In particular, phylogenetic analysis and structure analysis revealed that Bmmar15 (DD40D) formed a new basal subgroup of TC1/Mariner element in insects, which was referred to as bmori. Furthermore, we concluded that DD40D appeared to intermediate between mariner and Tc1. Finally, we estimated the insertion time for each copy of TC1/Mariner in the silkworm and found that most of members were dramatically amplified during a period from 0 to 1 mya. Moreover, the detailed functional data analysis showed that Bmmar1, Bmmar6 and Bmmar9 had EST evidence and intact transposases. These implied that TC1/Mariner might have potential transpositional activity. In conclusion, this study provides some new insights into the landscape, origin and evolution of TC1/Mariner in the insect genomes.  相似文献   

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Key message

Arabidopsis det1 mutants exhibit salt and osmotic stress resistant germination. This phenotype requires HY5, ABF1, ABF3, and ABF4.

Abstract

While DE-ETIOLATED 1 (DET1) is well known as a negative regulator of light development, here we describe how det1 mutants also exhibit altered responses to salt and osmotic stress, specifically salt and mannitol resistant germination. LONG HYPOCOTYL 5 (HY5) positively regulates both light and abscisic acid (ABA) signalling. We found that hy5 suppressed the det1 salt and mannitol resistant germination phenotype, thus, det1 stress resistant germination requires HY5. We then queried publically available microarray datasets to identify genes downstream of HY5 that were differentially expressed in det1 mutants. Our analysis revealed that ABA regulated genes, including ABA RESPONSIVE ELEMENT BINDING FACTOR 3 (ABF3), are downregulated in det1 seedlings. We found that ABF3 is induced by salt in wildtype seeds, while homologues ABF4 and ABF1 are repressed, and all three genes are underexpressed in det1 seeds. We then investigated the role of ABF3, ABF4, and ABF1 in det1 phenotypes. Double mutant analysis showed that abf3, abf4, and abf1 all suppress the det1 salt/osmotic stress resistant germination phenotype. In addition, abf1 suppressed det1 rapid water loss and open stomata phenotypes. Thus interactions between ABF genes contribute to det1 salt/osmotic stress response phenotypes.
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L-Lactate cytochrome c oxidoreductase (flavocytochrome b 2, FC b 2) from the thermotolerant methylotrophic yeast Hansenula polymorpha (Pichia angusta) is, unlike the enzyme form baker’s yeast, a thermostable enzyme potentially important for bioanalytical technologies for highly selective assays of L-lactate in biological fluids and foods. This paper describes the construction of flavocytochrome b 2 producers with over-expression of the H. polymorpha CYB2 gene, encoding FC b 2. The HpCYB2 gene under the control of the strong H. polymorpha alcohol oxidase promoter in a plasmid for multicopy integration was transformed into the recipient strain H. polymorpha C-105 (grc1 catX), impaired in glucose repression and devoid of catalase activity. A method was developed for preliminary screening of the transformants with increased FC b 2 activity in permeabilized yeast cells. The optimal cultivation conditions providing for the maximal yield of the target enzyme were found. The constructed strain is a promising FC b 2 producer characterized by a sixfold increased (to 3 μmol min?1 mg?1 protein in cell-free extract) activity of the enzyme.  相似文献   

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Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.  相似文献   

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Tuber huidongense and T. liyuanum are common commercial white truffles in China that belong to the Rufum and Puberulum groups of the genus Tuber, respectively. Their mycorrhizae were successfully synthesized with two native trees—Castanea mollissima and Pinus armandii—under greenhouse conditions. The identities of the mycorrhizae were confirmed through internal transcribed spacer (ITS) sequence analyses, and their morphological characteristics were described. All of the obtained mycorrhizae have an interlocking pseudoparenchymatous mantle, which is a typical feature of truffle mycorrhizae. The mycorrhizae of T. huidongense on the two trees have hyaline branched emanating hyphae, similar to the documented mycorrhizae of the Rufum group. The unramified, spiky, and hyaline cystidia on the mycorrhizae of T. liyuanum with both C. mollissima and P. armandii further confirmed that this characteristic is constant for the mycorrhizae of the Puberulum group. The successful mycorrhizal syntheses on the two nut-producing trees will be of economic importance in the cultivation of the two truffles.  相似文献   

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Bacterial species of Bacillus, Lactobacillus, and Bifidobacterium in the intestinal tract have been used as probiotics. Selections for probiotic candidates by the culture-based approaches are time-consuming and labor-consuming. The aim of this study was to develop a new method based on sequencing strategies to select the probiotic Bacillus, Lactobacillus, and Bifidobacterium. The Illumina-based sequencing strategies with different specific primers for Bacillus, Clostridium, and Bifidobacterium were applied to analyze diversity of the genera in goat feces. The average number of different Bacillus, Clostridium, and Bifidobacterium OTUs (operational taxonomic units) at the 97% similarity level ranged from 1922 to 63172. The coverage index values of Bacillus, Clostridium, and Bifidobacterium calculated from the bacterial OTUs were 0.89, 0.99, and 1.00, respectively. The most genera of Bacillus (37.9%), Clostridium (53%), and Bifidobacterium (99%) were detected in goat feces by the Illumina-based sequencing with the specific primers of the genera, respectively. Higher phylogenetic resolutions of the genera in goat feces were successfully established. The results suggest that the selection for probiotic Bacillus, Clostridium, and Bifidobacterium based on the Illumina sequencing with their specific primers is reliable and feasible, and the core Bacillus, Clostridium, and Bifidobacterium species of healthy goats possess the potentials as probiotic microbial consortia.  相似文献   

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Wheat Fusarium Head Blight (FHB), mainly caused by Fusarium graminearum (F.g), is a destructive fungal disease worldwide. FHB can not only cause considerable reduction in yield, but more seriously, can contaminate grain by trichothecene toxins released by the fungus. Here, we report new insights into the function and underlying mechanisms of a UDP-glycosyltransferase gene, Ta-UGT 3 , that is involved in FHB resistance in wheat. In our previous study, Ta-UGT 3 was found to enhance host tolerance against deoxynivalenol (DON) in Arabidopsis. In this study, four transgenic lines over-expressing Ta-UGT 3 in a FHB highly susceptible wheat variety, Alondra’s, were obtained and characterized. 3 years of assays using single floret inoculation with F.g indicated that all four transgenic lines exhibited significantly enhanced type II resistance to FHB and less DON accumulation in the grains compared to the untransformed control. Histological observation using GFP labelled F.g was in agreement with the above test results since over-expression of Ta-UGT 3 dramatically inhibited expansion of F.g. To explore the putative mechanism of resistance mediated by Ta-UGT 3 , microarray analysis, qRT-PCR and hormone measurements were performed. Microarray analysis showed that DON up-regulated genes, such as TaNPR1, in the susceptible control, and down-regulated genes in F.g inoculated transgenic lines, while qRT-PCR showed that some defence related genes were up-regulated in F.g inoculated transgenic lines. Ta-UGT 3 over-expression also changed the contents of the endogenous hormones SA and JA in the spikes. These data suggest that Ta-UGT 3 positively regulates the defence responses to F.g, perhaps by regulating defence-related and DON-induced downstream genes.  相似文献   

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Background

Leishmaniasis and malaria are the two most common parasitic diseases and responsible for large number of deaths per year particularly in developing countries like Pakistan. Majority of Pakistan population rely on medicinal plants due to their low socio-economic status. The present review was designed to gather utmost fragmented published data on traditionally used medicinal plants against leishmaniasis and malaria in Pakistan and their scientific validation.

Methods

Pub Med, Google Scholar, Web of Science, ISI Web of knowledge and Flora of Pakistan were searched for the collection of data on ethnomedicinal plants. Total 89 articles were reviewed for present study which was mostly published in English. We selected only those articles in which complete information was given regarding traditional uses of medicinal plants in Pakistan.

Results

Total of 56 plants (malaria 33, leishmaniasis 23) was found to be used traditionally against reported parasites. Leaves were the most focused plant part both in traditional use and in in vitro screening against both parasites. Most extensively used plant families against Leishmaniasis and Malaria were Lamiaceae and Asteraceae respectively. Out of 56 documented plants only 15 plants (Plasmodia 4, Leishmania 11) were assessed in vitro against these parasites. Mostly crude and ethanolic plant extracts were checked against Leishmania and Plasmodia respectively and showed good inhibition zone. Four pure compounds like artemisinin, physalins and sitosterol extracted from different plants proved their efficacy against these parasites.

Conclusions

Present review provides the efficacy and reliability of ethnomedicinal practices and also invites the attention of chemists, pharmacologist and pharmacist to scientifically validate unexplored plants that could lead toward the development of novel anti-malarial and anti-leishmanial drugs.
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In this contribution on the genus Cantharellus in Asia, C. subvaginatus is described from the Republic of Korea as a close relative to the Chinese C. vaginatus, which is here reported for the first time from India. Both species are here placed in Cantharellus subg. Cantharellus sect. Amethystini, together with the Indian C. pseudoformosus (syn.: C. umbonatus) and the Malayan C. subamethysteus. As such, Asia has suddenly become the continent with the highest diversity for Amethystini. Species delimitation in sect. Amethystini is molecularly supported by a combined phylogenetic analysis of rDNA sequences obtained for LSU and ITS and additionally suggests the existence of a still undescribed species in North America. Character variability is discussed for all known members of Amethystini, including atypical specimens of the North American C. lewisii that are morphologically more reminiscent of the South Korean C. subvaginatus.  相似文献   

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A complex study on the adaptation of cn and vn mutants and the allozymes of alcoholdehydrogenase (ADH) was carried out in initially pure lines, and their panmixia populations during exchange of the mutant genotype with that of wild-type flies (C-S) and D) through saturating crossings. The relative adaptation of the genotypes was estimated by their effect on reproductive efficiency in the experimentally obtained population. Fecundity, lifespan, and the resistance of the studied genotypes to hyperthermia were investigated individually. It was shown that the high level of adaptation of the cn mutants and the low level of adaptation of the vg mutants was correlated with the presence of different ADH allozymes. In the studied population, the F-allozyme of ADH accompanied the vg mutation, while the S-allozyme of the enzyme was detected in cn mutants. Saturating crossings of C-S(Adh Svg(Adh F) and D(Adh F) × cn(Adh S), along with the parallel determination of the allele composition of the Adh locus, demonstrated that the complete substitution of the F-allozyme of ADH in the vg mutants by the S-allozyme in D flies, as well as the substitution of the S-allozyme of ADH in the cn mutants by the F-allozyme in D flies was realized only after the 15th–20th backcrosses. These results favor the coadaptation of cn and vg marker genes with alleles of the Adh locus and indicate the important role of the latter in the adaptation of genotypes. In the studied population, selection acted primarily against the vg mutants, which were inferior to the cn mutants, and heterozygote genotypes in indices of the main adaptation components.  相似文献   

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