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1.
Two extracellular enzymes (MsP1 and MsP2) capable of efficient β-carotene degradation were purified from culture supernatants of the basidiomycete Marasmius scorodonius (garlic mushroom). Under native conditions, the enzymes exhibited molecular masses of ~150 and ~120 kDa, respectively. SDS-PAGE and mass spectrometric data suggested a composition of two identical subunits for both enzymes. Biochemical characterisation of the purified proteins showed isoelectric points of 3.7 and 3.5, and the presence of heme groups in the active enzymes. Partial amino acid sequences were derived from N-terminal Edman degradation and from mass spectrometric ab initio sequencing of internal peptides. cDNAs of 1,604 to 1,923 bp, containing open reading frames (ORF) of 508 to 513 amino acids, respectively, were cloned from a cDNA library of M. scorodonius. These data suggest glycosylation degrees of ~23% for MsP1 and 8% for MsP2. Databank homology searches revealed sequence homologies of MsP1 and MsP2 to unusual peroxidases of the fungi Thanatephorus cucumeris (DyP) and Termitomyces albuminosus (TAP).  相似文献   

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Dana Bernátová 《Biologia》2008,63(2):175-176
The paper brings information on an isolated occurrence and morphological characters of Carex × involuta and C. juncella populations in the Vel’ká Fatra Mts. Their presence has been known neither from the territory of Slovakia nor from the whole Western Carpathians till now.  相似文献   

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A carotenoid gene (crtR-B) from the green alga Haematococcus pluvialis, encoding β-carotene hydroxylase that was able to catalyze the conversion of β-carotene to zeaxanthin and canthaxanthin to astaxanthin, was cloned into Chlamydomonas reinhardtii chloroplast expression vector p64D to yield plasmid p64DcrtR-B. The vector p64DcrtR-B was transferred to the chloroplast genome of C. reinhardtii using micro-particle bombardment. PCR and Southern blot analyses indicated that crtR-B was integrated into the chloroplast genome of the transformants. RT-PCR assays showed that the H. pluvialis crt R-B gene was expressed in C. reinhardtii transformants. The transformants rapidly synthesized carotenoids in larger quantities than the wild-type upon being transferred from moderate to high-intensity white light. This research provides a foundation for further study to elucidate the possible mechanism of photo-protection by xanthophylls and other carotenoids in high light conditions or through exposure to UV radiation.  相似文献   

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Schistosomiasis, currently the second most common parasitic disease of humans in tropical regions is caused by the eggs of trematode worms of the genus Schistosoma. Understanding egg formation and specifically the synthesis of the eggshell comprises, consequently, a promising starting point to cure and prevent the disease. To shed light on the genetics of the latter process, we analysed the three known S. mansoni eggshell proteins P14, P19 and P48 against the background of the species inferred proteome and of eggshell proteins identified in other trematode species. Our results suggest that eggshell formation in Schistosoma involves a multitude of different proteins organised in currently three distinct protein families (P14, P48 and P34 eggshell protein family). The first two families are of simple structure. Their respective members share a substantial degree of sequence similarity and are, to date, observed only in the genus Schistosoma. In contrast, the P34 family of eggshell proteins is complex. Its in part highly diverged members share only a conserved motif of 67-aa length on average and are detected in various trematode species. The resulting widespread occurrence of this protein motif suggests an important role during eggshell formation in trematodes. Screening more than 7,000 putative proteins of S. mansoni, we could identify six new members of the P34 protein family that are likely to be involved in eggshell formation in this species.Electronic Supplementary Material Supplementary material is available for this article at .  相似文献   

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We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells.  相似文献   

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The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically active lipase from a basidiomycete fungus.  相似文献   

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Background  

The presence of β-lactamases in Y. enterocolitica has been reported to vary with serovars, biovars and geographical origin of the isolates. An understanding of the β-lactamases in other related species is important for an overall perception of antibiotic resistance in yersiniae. The objective of this work was to study the characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii, isolated from clinical and non-clinical sources in India.  相似文献   

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Much attention has been focused on the study of lactoferrin at the protein or nucleotide level in mice, humans, and cattle, but little is known about it in goats. The goat LF gene from 5' UTR to exon 17 was amplified, and the variation of g.7605C→T in 10 Chinese indigenous goat breeds was analyzed. Among the three ruminant species (cattle, sheep, and goats), the intron-exon distribution pattern was similar, and all the exons had the same length, but the length of introns varied greatly due to insertions or deletions. The frequency of allele T at g.7605C→T (50.12%) was a little higher than that of allele C (49.88%), and the genotype distribution differed greatly between goat populations. The g.7605C→T site showed higher genetic diversity in goat populations. The genetic differentiation was 0.0783, and gene flow was 2.9433 among the 10 Chinese indigenous goat populations.  相似文献   

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Different lines of cell suspension cultures of Taxus × media Rehd. and Taxus floridana Nutt. were cryopreserved with a two-step freezing method using a simple and inexpensive freezing container instead of a programmable freezer. Four to seven days old suspension cell cultures were precultured in growth medium supplemented with 0.5 M mannitol for 2 d. The medium was then replaced with cryoprotectant solution (1 M sucrose, 0.5 M glycerol and 0.5 M dimethylsulfoxide) and the cells incubated on ice for 1 h. Before being plunged into liquid nitrogen, cells were frozen with a cooling rate of approximately −1 °C per min to −80 °C. The highest post-thaw cell viability was 90 %. The recovery was line dependent. The cryopreservation procedure did not alter the nuclear DNA content of the cell lines. The results indicate that cryopreservation of Taxus cell suspension cultures using inexpensive freezing container is possible.  相似文献   

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Efficient transformation of leaf disc-derived callus of Codonopsis lanceolata was obtained using Agrobacterium tumefaciens strain LBA4404 harboring a binary vector, pYBI121, that carries the neomycin phosphotransferase (npt II) gene as a selectable marker. The green shoots recovered from agroinfected explants on selection medium (containing 0.1 mg/l α-naphthaleneacetic acid (NAA), 1 mg/l 6-benzylaminopurine (BAP), 100 mg/l kanamycin, and 250 mg/l cefotaxime) were rooted on Murashige and Skoog (MS) medium supplemented with 2 mg/l IBA and 10 mg/l kanamycin. To optimize the transformation conditions, several factors were assessed, including the co-cultivation period, the duration of pre- and post-culture in darkness and light, the kanamycin concentration, and the Agrobacterium densities. We produced transgenic Codonopsis lanceolata overexpressing γ-tocopherol methyltransferase (γ-TMT) by this protocol. Moreover, the α-tocopherol content of the plants was enhanced by the overexpression of this gene. Bimal Kumar Ghimire and Eun Soo Seong contributed equally to this work.  相似文献   

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Recombinant Zantedeschia aethiopica agglutinin (ZAA) was expressed in Escherichia coli as N-terminal His-tagged fusion. After induction with isopropylthio-β-d-galactoside (IPTG), the recombinant ZAA was purified by metal-affinity chromatography. The purified ZAA protein was applied in anti-fungal assay and the result showed that recombinant ZAA had anti-fungal activity towards leaf mold (Fulvia fulva), one of the most serious phytopathogenic fungi causing significant yield loss of crops. This study suggests that ZAA could be an effective candidate in genetic engineering of plants for the control of leaf mold.  相似文献   

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The menadione reductase (MNR), the nicotinamide adenine dinucleotide dehydrogenase (NDH) and diaphorase (DIA) isozymes were studied in the allohexaploid Triticum aestivum cv ”Chinese Spring” and in five diploid Triticeae species. The Mnr1, Ndh3 and Dia1 loci were located on the chromosome arms 3AL, 3BL and 3DL of T. aestivum, respectively. These loci were also located on the 3H chromosome of Hordeum vulgare cv ”Betzes”, the 3L chromosome of Aegilops longissima and the 6RL chromosome arm of Secale cereale cv ”Imperial”. The chromosomal location results together with the segregation studies support a tetrameric behaviour of the MNR1, NDH3 and DIA1 isozymes. The Ndh1 and Dia3 loci were located on homoeologous group 4 showing a monomeric behaviour. The chromosomal locations and linkage data of the Mnr, Ndh and Dia loci suggest that Mnr1=Ndh3=Dia1; Ndh1=Dia3 and Ndh2=Dia2. Received: 3 June 2001 / Accepted: 11 July 2001  相似文献   

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To facilitate molecular genetic studies of Streptomyces ambofaciens that produces spiramycin, a commercially important macrolide antibiotic used in human medicine against Gram-positive pathogenic bacteria, the conditions for the conjugal transfer of DNA from E. coli to S. ambofaciens were established using a bacteriophage ϕC31 att/int system. The transconjugation efficiency of S. ambofaciens varied with the medium used; the highest frequency was obtained on AS-1 medium containing 10 mM MgCl2 without heat treatment of the spores. In addition, by cloning and sequencing the attB site, we identified that S. ambofaciens contains a single attB site within an ORF coding for a pirin homolog, and its attB site sequence shows 100% nt identity to the sequence of S. coelicolor and S. lividans, which have the highest efficiency in transconjugation using the ϕC31 att/int system.  相似文献   

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The βNACtes gene family of the Drosophila melanogaster genome provides a model for investigating the mechanisms of the molecular evolution of recently evolved genes. The βNACtes genes code for proteins that are homologous to the subunit of the nascent polypeptide-associated complex (NAC), are expressed exclusively in the testis, and are localized on the X chromosome as two-gene clusters and one separate copy. Population polymorphism of the βNACtes genes was studied using several wild-type D. melanogaster stocks, and βNACtes paralogs were compared with each other. A heterogeneous pattern was observed for βNACtes polymorphism: the 3′ genes of the two-gene clusters were low polymorphic, whereas, separate, the βNACtes1 gene was the most variable. The 5′ βNACtes copies of the two-gene tandems were practically identical, whereas the 3′ βNACtes copies were highly diverged. Hence, local gene conversion was assumed to provide for the selective homogenization of the 5′ genes. A comparison of the βNACtes paralogs showed that the majority of amino acid differences were in the N-terminal region, containing the βNAC domain. The McDonald-Kreitman test was used to analyze the divergence of βNACtes paralogs and implicated positive selection in the evolution of the βNACtes gene family.  相似文献   

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Mutations in the Leucine Reach Repeat Kinase 2 (LRRK2) gene are the most frequent cause of familial Parkinson’s disease (PD). Although the precise physiological and pathological roles of LRRK2 are unclear, a direct link between mutant LRRK2 and programmed cell death (apoptosis) has been suggested. By using flow cytometry (PI+Annexin V(FITC)), we showed an increased level of spontaneous lymphocyte apoptosis in patients with LRRK2-associated PD compared to controls after 24 h (p < 0.016) and 48 h (p < 0.031) of incubation (5% CO2, 37°C). We found an increased FAS mRNA level in peripheral blood lymphocytes of patients with LRRK2-associated PD compared to controls (p < 0.05) and to sporadic PD (sPD) (p < 0.002). A significant difference in FAS expression between patients with LRRK2-associated PD and controls remained after 3 years and was detected after 1 and 24 h during lymphocyte incubation (p < 0.03 and 0.05, respectively). Increased spontaneous lymphocyte apoptosis, along with increased FAS expression, in patients with LRRK2-associated PD suggests that LRRK2 mutations may lead to preferable activation of extrinsic apoptotic way.  相似文献   

20.
Graptolites from the Jaeger collection at the Museum für Naturkunde (Berlin, Germany) provide important information on structural details of Silurian (Wenlock–Ludlow) retiolitids as well as for the biostratigraphic and biogeographic distribution of these magnificent graptolites. Species of the genera Cometograptus, Spinograptus and Plectograptus are described from isolated glacial boulder material, collected in northern Germany and from shale specimens found in the Lower Graptolite Shale of Thuringia. The biostratigraphic placement of material derived from glacial erratic boulders, however, is far from being precise. The fauna associated with the neotype of Plectograptus macilentus in the ‘Unterer Graptolithenschiefer’ of Thuringia is discussed and illustrated. Cometograptus alfeisenacki from the Cyrtograptus lundgreni Biozone is recognized as a new species. The genus is discovered for the first time in North German glacial erratic boulders.  相似文献   

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