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1.
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
2.
Matías Maggi Natalia Damiani Sergio Ruffinengo David De Jong Judith Principal Martín Eguaras 《Experimental & applied acarology》2010,50(3):269-279
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
3.
4.
Bimal Kumar Ghimire Eun Soo Seong Jung Dae Lim Kweon Heo Myong Jo Kim Ill-Min Chung John A. Juvik Chang Yeon Yu 《Plant Cell, Tissue and Organ Culture》2008,95(3):265-274
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
5.
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
6.
G. I. Naumov M. Yu. Shalamitskiy E. S. Naumova 《Doklady. Biochemistry and biophysics》2016,467(1):89-91
Using yeast genome databases and literature data, we have conducted a phylogenetic analysis of pectinase PGU genes from Saccharomyces strains assigned to the biological species S. arboricola, S. bayanus (var. uvarum), S. cariocanus, S. cerevisiae, S. kudriavzevii, S. mikatae, S. paradoxus, and hybrid taxon S. pastorianus (syn. S. carlsbergensis). Single PGU genes were observed in all Saccharomyces species, except S. bayanus. The superfamily of divergent PGU genes has been documented in S. bayanus var. uvarum for the first time. Chromosomal localization of new PGU1b, PGU2b, and PGU3b genes in the yeast S. bayanus var. uvarum has been determined by molecular karyotyping and Southern hybridization. 相似文献
7.
Michael G. Cripps Grant R. Edwards Graeme W. Bourdôt David J. Saville Hariet L. Hinz Simon V. Fowler 《Plant Ecology》2010,209(1):123-134
Cirsium arvense (L.) Scop. (Californian, Canada, or creeping thistle) is an exotic perennial herb indigenous to Eurasia that successfully
established in New Zealand (NZ) approximately 130 years ago. Presently, C. arvense is considered one of the worst invasive weeds in NZ arable and pastoral productions systems. A mechanism commonly invoked
to explain the apparent increased vigour of introduced weeds is release from natural enemies. The enemy-release hypothesis
(ERH) predicts that plants in an introduced range should experience reduced herbivory, particularly from specialists, and
that release from this natural enemy pressure facilitates increased plant performance in the introduced range. In 2007, surveys
were carried out in 13 populations in NZ (7 in the North Island and 6 in the South Island) and in 12 populations in central
Europe to quantify and compare growth characteristics of C. arvense in its native versus introduced range. Altitude and mean annual precipitation for each population were used as covariates
in an attempt to explain differences or similarities in plant traits among ranges. All plant traits varied significantly among
populations within a range. Shoot dry weight was greater in the South Island compared to Europe, which is in line with the
prediction of increased plant performance in the introduced range; however, this was explained by environmental conditions.
Contrary to expectations, the North Island was not different from Europe for all plant traits measured, and after adjustment
for covariates showed decreased shoot density and dry weight compared to the native range. Therefore, environmental factors
appear to be more favourable for growth of C. arvense in both the North and South Islands. In accordance with the ERH, there was significantly greater endophagous herbivory in
the capitula and stems of shoots in Europe compared to both NZ ranges. In NZ, capitulum attack from Rhinocyllus conicus was found only in the North Island, and no stem-mining attack was found anywhere in NZ. Thus, although C. arvense experiences significantly reduced natural enemy pressure in both the North and South Islands of NZ there is no evidence that
it benefits from this enemy release. 相似文献
8.
Recently, the gene coding for a new beta-glucuronidase enzyme has been identified and cloned from Streptococcus equi subsp. zooepidemicus. This is another report of a beta-glucuronidase gene cloned from bacterial species. The ORF Finder analysis of a sequenced
DNA (EMBL, AJ890474) revealed a presence of 1,785 bp large ORF potentially coding for a 594 aa protein. Three protein families
in (Pfam) domains were identified using the Conserved Domain Database (CDD) analysis: Pfam 02836, glycosyl hydrolases family
2, triose phosphate isomerase (TIM) barrel domain; Pfam 02837, glycosyl hydrolases family 2, sugar binding domain; and Pfam
00703, glycosyl hydrolases family 2, immunoglobulin-like beta-sandwich domain. To gain more insight into the enzymatic activity,
the domains were used to generate a bootstrapped unrooted distance tree using ClustalX. The calculated distances for two domains,
TIM barrel domain, and sugar-binding domain were comparable and exhibited similarity pattern based on function and thus being
in accordance with recently published works confirming beta-glucuronidase activity of the enzyme. The calculated distances
and the tree arrangement in the case of centrally positioned immonoglobulin-like beta-sandwich domain were somewhat higher
when compared to other two domains but clustering with other beta-glucuronidases was rather clear. Nine proteins, including
beta-glucuronidases, beta-galactosidase, and mannosidase were selected for multiple alignment and subsequent distance tree
creation. 相似文献
9.
Root segments from seedlings of Panax ginseng produced adventitious roots directly when cultured on 1/2 MS solid medium lacking NH4NO3 and containing 3.0 mg l−1 IBA. Using this adventitious root formation, we developed rapid and efficient transgenic root formation directly from adventitious
root segments in P. ginseng. Root segments were co-cultivated with Agrobacterium tumefaciens (GV3101) caring β-glucuronidase (GUS) gene. Putative transgenic adventitious roots were formed directly from root segments on medium with 400 mg l−1 cefotaxime and 50 mg l−1 kanamycin. Kanamycin resistant adventitious roots were selected and proliferated as individual lines by subculturing on medium
with 300 mg l−1 cefotaxime and 50 mg l−1 kanamycin at two weeks subculture interval. Frequency of transient and stable expression of GUS gene was enhanced by acetosyringon (50 mg l−1) treatment. Integration of transgene into the plants was confirmed by the X-gluc reaction, PCR and Southern analysis. Production
of transgenic plants was achieved via somatic embryogenesis from the embryogenic callus derived from independent lines of
adventitious roots. The protocol for rapid induction of transgenic adventitious roots directly from adventitious roots can
be applied for a new Agrobacterium tumefaciens-mediated genetic transformation protocol in P. ginseng. 相似文献
10.
11.
Konstantin V. Kiselev Anna V. Turlenko Yuri N. Zhuravlev 《Plant Growth Regulation》2009,59(3):237-243
12.
Nathaniel Liddy Peter E. Molloy Alan D. Bennett Jonathan M. Boulter Bent K. Jakobsen Yi Li 《Molecular biotechnology》2010,45(2):140-149
Previously, we have described the use of phage display to generate high affinity disulfide bond-linked T cell receptors (TCRs).
The affinities of the mutant TCRs were analysed after refolding of separately expressed α and β chains from Escherichia coli inclusion bodies. This approach is only suitable for the analysis of small numbers of TCR variants. An attractive alternative
would be soluble expression within the bacterial periplasm, but the generic production of TCRs within the E. coli periplasm has so far not proved successful. Here we show that functional, soluble TCR can be produced within the cytoplasm
of trxB gor mutant E. coli strains, with maximum yields of 3.4 mg/l. We also investigated the effect of coexpressing the folding modulators Skp and
DsbC finding that the TCR expression levels were largely unaffected by these chaperones. Importantly, we demonstrated that
the amount of protein purified from 50 ml starter cultures was sufficient to show functionality of the TCR by specific antigen
binding in both ELISA and surface plasmon resonance (SPR) assays. This TCR production method has the potential to allow rapid
and medium throughput analysis of affinity-matured TCRs selected from TCR phage display libraries. 相似文献
13.
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
14.
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
15.
Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified
as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing conservative features. A. bockmanni shows 2n = 50 chromosomes, a karyotypic formula composed of 10 M + 12SM + 12ST + 16A and multiple Ag-NORs. Eight positive signals
in subtelocentric/acrocentric chromosomes were identified by fluorescent in situ hybridization (FISH) with 18S rDNA probes.
After FISH with 5S rDNA probes, four sites were detected, comprising the interstitial region of a metacentric pair and the
terminal region on long arms of another metracentric pair. Little amounts of constitutive heterochromatin were observed, mainly
distributed at distal region in two chromosomal pairs. Additionally, heterochromatin was also located close to the centromeres
in some chromosomes. No positive signals were detected in the chromosomes of A. bockmanni by FISH with the As-51 satellite DNA probe. The studied species combines a set of characteristics previously identified in
two different Astyanax groups. The chromosomal evolution in the genus Astyanax is discussed. 相似文献
16.
In Escherichia coli cellular levels of pppGpp and ppGpp, collectively called (p)ppGpp, are maintained by the products of two genes, relA and spoT. Like E. coli, Vibrio cholerae also possesses relA and spoT genes. Here we show that similar to E. coli, V. cholerae ΔrelA cells can accumulate (p)ppGpp upon carbon starvation but not under amino acid starved condition. Although like in E. coli, the spoT gene function was found to be essential in V. cholerae
relA
+ background, but unlike E. coli, several V. cholerae ΔrelA ΔspoT mutants constructed in this study accumulated (p)ppGpp under glucose starvation. The results suggest a cryptic source of
(p)ppGpp synthesis in V. cholerae, which is induced upon glucose starvation. Again, unlike E. coli ΔrelA ΔspoT mutant (ppGpp0 strain), the V. cholerae ΔrelA ΔspoT mutants showed certain unusual phenotypes, which are (a) resistance towards 3-amino-1,2,4-triazole (AT); (b) growth in nutrient
poor M9 minimal medium; (c) ability to stringently regulate cellular rRNA accumulation under glucose starvation and (d) initial
growth defect in nutrient rich medium. Since these phenotypes of ΔrelA ΔspoT mutants could be reverted back to ΔrelA phenotypes by providing SpoT in trans, it appears that the spoT gene function is crucial in V. cholerae.
Part of this work was presented at the International Symposium on Chemical Biology, Kolkata, India, 7–9 March 2007. 相似文献
17.
Chaoyi Liu Huanwen Xu Jing Jiang Sui Wang Guifeng Liu 《Plant Cell, Tissue and Organ Culture》2018,132(1):191-199
18.
Pueyo A Figueiras AM Benito C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):513-517
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
19.
Erwinia carotovora subspecies betavasculorum, also known as E. betavasculorum and Pectobacterium betavasculorum, is a soil bacterium that has the capacity to cause root rot necrosis of sugarbeets. The qualitatively different pathogenicity exhibited by the virulent E. carotovora strain and two avirulent strains, a Citrobacter sp. and an Enterobacter cloacae, was examined using digital analysis of photographic evidence of necrosis as well as for carbohydrate, ethane, and ethylene
release compared with uninoculated potato tuber slices. Visual scoring of necrosis was superior to digital analysis of photographs.
The release of carbohydrates and ethane from potato tuber slices inoculated with the soft rot necrosis-causing Erwinia was significantly greater than that of potato tuber slices that had not been inoculated or that had been inoculated with
the nonpathogenic E. cloacae and Citrobacter sp. strains. Interestingly, ethylene production from potato slices left uninoculated or inoculated with the nonpathogenic
Citrobacter strain was 5- to 10-fold higher than with potato slices inoculated with the pathogenic Erwinia strain. These findings suggest that (1) carbohydrate release might be a useful measure of the degree of pathogenesis, or
relative virulence; and that (2) bacterial suppression of ethylene formation may be a critical step in root rot disease formation. 相似文献
20.
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