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1.
Maksymilian Zienkiewicz Tomasz Krupnik Anna Drożak Wioleta Wasilewska Anna Golke Elżbieta Romanowska 《Plant molecular biology》2018,96(1-2):135-149
Key message
We have successfully produced single-cell colonies of C. merolae mutants, lacking the PsbQ’ subunit in its PSII complex by application of DTA-aided mutant selection. We have investigated the physiological changes in PSII function and structure and proposed a tentative explanation of the function of PsbQ’ subunit in the PSII complex.Abstract
We have improved the selectivity of the Cyanidioschyzon merolae nuclear transformation method by the introduction of diphtheria toxin genes into the transformation vector as an auxiliary selectable marker. The revised method allowed us to obtained single-cell colonies of C. merolae, lacking the gene of the PsbQ’ extrinsic protein. The efficiency of gene replacement was extraordinarily high, allowing for a complete deletion of the gene of interest, without undesirable illegitimate integration events. We have confirmed the absence of PsbQ’ protein at genetic and protein level. We have characterized the physiology of mutant cells and isolated PSII protein complex and concluded that PsbQ’ is involved in nuclear regulation of PSII activity, by influencing several parameters of PSII function. Among these: oxygen evolving activity, partial dissociation of PsbV, regulation of dimerization, downsizing of phycobilisomes rods and regulation of zeaxanthin abundance. The adaptation of cellular physiology appeared to favorite upregulation of PSII and concurrent downregulation of PSI, resulting in an imbalance of energy distribution, decrease of photosynthesis and inhibition of cell proliferation.2.
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
3.
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
4.
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
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.
Razi H Howell EC Newbury HJ Kearsey MJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(2):179-192
Previous locations of flowering time (FT) QTL in several Brassica species, coupled with Arabidopsis synteny, suggest that orthologues of the genes FLC, FY or CONSTANS might be the candidates. We focused on FLC, and cloned paralogous copies in Brassica oleracea, obtained their genomic DNA sequences, and confirmed their locations relative to those of known FT-QTL by genetical mapping.
They varied in total length mainly due to the variable size of the first and last introns. A high level of identity was observed
among Brassica
FLC genes at the amino acid level but non-synonymous differences were present. Comparative analysis of the promoter and intragenic
regions of BoFLC paralogues with Arabidopsis
FLC revealed extensive differences in overall structure and organisation but showed high conservation within those segments known
to be essential in regulating FLC expression. Four B. oleracea
FLC copies (BoFLC1, BoFLC3, BoFLC4 and BoFLC5) were located to their respective linkage groups based on allelic sequence variation in lines from a doubled haploid population.
All except BoFLC4 were within the confidence intervals of known FT-QTL. Sequence data indicated that relevant non-synonymous polymorphisms
were present between parents A12DHd and GDDH33 for BoFLC genes. However, BoFLC alleles segregated independently of FT in backcrosses while the study provided evidence that BoFLC4 and BoFLC5 contain premature stop codons and so could not contribute to flowering time variation. Therefore, there is strong evidence
against any of the 4 BoFLC being FT-QTL candidates in this population. 相似文献
7.
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
8.
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
9.
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
10.
Konstantin V. Kiselev Anna V. Turlenko Yuri N. Zhuravlev 《Plant Growth Regulation》2009,59(3):237-243
11.
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
12.
Aulus EAD Barbosa Érika VS Albuquerque Maria CM Silva Djair SL Souza Osmundo B Oliveira-Neto Arnubio Valencia Thales L Rocha Maria F Grossi-de-Sa 《BMC biotechnology》2010,10(1):44
Background
Coffee is an important crop and is crucial to the economy of many developing countries, generating around US70 billion per year. There are 115 species in the < i > Coffea < /i > genus, but only two, < i > C. arabica < /i > and < i > C. canephora < /i > , are commercially cultivated. Coffee plants are attacked by many pathogens and insect-pests, which affect not only the production of coffee but also its grain quality, reducing the commercial value of the product. The main insect-pest, the coffee berry borer ( < i > Hypotheneumus hampei < /i > ), is responsible for worldwide annual losses of around US70 billion per year. There are 115 species in the Coffea genus, but only two, C. arabica and C. canephora, are commercially cultivated. Coffee plants are attacked by many pathogens and insect-pests, which affect not only the production of coffee but also its grain quality, reducing the commercial value of the product. The main insect-pest, the coffee berry borer (Hypotheneumus hampei), is responsible for worldwide annual losses of around US500 million. The coffee berry borer exclusively damages the coffee berries, and it is mainly controlled by organochlorine insecticides that are both toxic and carcinogenic. Unfortunately, natural resistance in the genus Coffea to H. hampei has not been documented. To overcome these problems, biotechnological strategies can be used to introduce an α-amylase inhibitor gene (α-AI1), which confers resistance against the coffee berry borer insect-pest, into C. arabica plants. 相似文献13.
Chaoyi Liu Huanwen Xu Jing Jiang Sui Wang Guifeng Liu 《Plant Cell, Tissue and Organ Culture》2018,132(1):191-199
14.
The blattisociid mite Lasioseius floridensis Berlese was found associated with the broad mite, Polyphagotarsonemus latus (Banks), on gerbera leaves in Mogi das Cruzes, State of Sao Paulo, Brazil. Blattisociid mites are not common on aerial plant
parts, except under high air humidity levels. Some Lasioseius species have been mentioned as effective control agents of rice pest mites, but nothing is known about the biology of L. floridensis. The objective of this study was to evaluate whether the observed co-occurrence of L. floridensis and P. latus was just occasional or whether the latter could be important as food source for the former, assumed by laboratory evaluation
of the ability of the predator to maintain itself, reproduce and develop on that prey. Biological parameters of L. floridensis were compared when exposed to P. latus and to other items as food. The study showed that mating is a pre-requisite for L. floridensis to oviposit and that oviposition rate was much higher on the soil nematode Rhabditella axei (Cobbold) (Rhabditidae) than on P. latus. Ovipositon on the acarid mite Tyrophagus
putrescentiae (Schrank) was about the same as on P. latus, but it was nearly zero when the predator was fed the fungi Aspergillus
flavus Link or Penicillium sp., or cattail (Typha sp.) pollen. Survivorship was higher in the presence of pollen and lower in the presence of A.
flavus or Penicillium sp. than in the absence of those types of food. Life table parameters indicated that the predator performed much better on
R. axei than on P. latus. To evaluate the potential effect of L. floridensis as predator of P. latus, complementary studies are warranted to determine the frequency of migration of L. floridensis to aerial plant parts, when predation on P. latus could occur. 相似文献
15.
Of the genes involved in galactose metabolism, GAL7, GAL10, and GAL1 are tightly linked in this order on chromosome II in Saccharomyces cerevisiae. While several species of the order Saccharomycetales have similar gene organization, Kazachstania naganishii is unique, in which GAL7 and GAL1 are close to each other whereas GAL10 is substantially apart from them on chromosome XI. In this study, we inserted the recognition sequence of I-SceI homing-endonuclease into GAL10 and also into the intervening segment of GAL7-GAL1. By cleaving chromosome DNA of the gene-manipulated strain with I-SceI, we obtained evidence that chromosome XI (610 kbp) was replaced with three fragments (305, 265, and 40 kbp). Using appropriate
probes, we further found that GAL10 was about 40 kbp apart from the GAL7-GAL1 cluster and that orientation of GAL10 was reversed comparing to the S. cerevisiae counter part. We, therefore, contend that comparison of the organization of the GAL cluster among Saccharomycetales is of importance to elucidate evolution of chromosomes and that the experimental scheme developed
in this study is useful for this line of investigation. 相似文献
16.
Jörg Maletz 《Pal?ontologische Zeitschrift》2010,84(4):501-522
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
17.
18.
Labruna MB Pacheco RC Nava S Brandão PE Richtzenhain LJ Guglielmone AA 《Microbial ecology》2007,54(1):126-133
The tick species, Amblyomma neumanni (Acari: Ixodidae) is the most frequent tick parasitizing humans in northwestern Argentina. The present study evaluated the
rickettsial infection among 55 A. neumanni adult free-living ticks collected in Dean Funes, Córdoba Province. Ticks were individually processed by the hemolymph test
with Gimenez staining, isolation of rickettsia in Vero cell culture by the shell vial technique, and polymerase chain reaction
(PCR) targeting the citrate synthase rickettsial gene. Through the shell vial technique, rickettsiae were successfully isolated
and established in Vero cell culture from two ticks (ticks 4 and 13), which previously showed to contain Rickettsia-like organisms by the hemolymph test. These two Rickettsia isolates were designated as An4 and An13. Molecular characterization (partial DNA sequences of two to three rickettsial genes
were determined) of these two isolates and phylogenetic analyses identified them as Rickettsia bellii (isolate An4) and Candidatus “Rickettsia amblyommii” (isolate An13). After testing all A. neumanni ticks by PCR, the prevalence of Candidatus
R. amblyommii and R. bellii was 23.6% (13/55) and 3.6% (2/55), respectively. These two rickettsiae have been considered of unknown pathogenicity and
appropriate studies to test their pathogenicity to humans or animals need to be conducted. This is the first report of Rickettsia in ticks from Argentina, and also in the species A. neumanni. The results reinforce previous findings that R. bellii (and probably Candidatus
R. amblyommii) are widespread among some Neotropical Amblyomma species, suggesting that these ticks gained these bacterial agents from a common ancestor and/or by recent horizontal transmission
of rickettsiae between ticks. 相似文献
19.
Jingzhi Li Ruiqi Feng Zhihui Wen Aili Zhang 《Biotechnology and Bioprocess Engineering》2017,22(4):382-389
To investigate effects of different pyruvate decarboxylases on isobutanol titers in Saccharomyces cerevisiae, single-gene deletion of the three PDCs genes encoding pyruvate decarboxylases were constructed in this study. In addition, we over-expressed Ilv2, which catalyzed the first step in the valine synthetic pathway, and Bat2, which was the cytoplasmic branched-chain amino-acid aminotransferase that catalyzed L-valine to 2-ketoisovalerate, to increase isobutanol production in the genetically modified strains. Our results showed that knockout of PDC5 were one of the main factors among the three PDC genes for improving isobutanol titers in S. cerevisiae. Additionally, we found that deletion of PDC5 in strain carrying overexpressed ILV2 and ARO10 resulted in 8-fold higher isobutanol productivity as compared to the control strain in micro-aerobic fermentations. Our results also suggested that engineered strain pdc5ΔpILV2 pARO10 generated lower ethanol titers and higher acetate acid titers than the control strain, while the growth rate and glucose consumption rate of engineered strain pdc5ΔpILV2 pARO10 were slightly lower than that of the control strain. Meanwhile, the biomass concentration of pdc5ΔpILV2 pARO10 decreased dramatically than that of the control strain. 相似文献
20.
Abdul Ghaffar Sher Afzal Khan Zahid Mukhtar Muhammad Ibrahim Rajoka Farooq Latif 《Molecular biology reports》2011,38(5):3227-3233
We studied heterologous expression of xylanase 11A gene of Chaetomium thermophilum in Pichia pastoris and characterized the thermostable nature of the purified gene product. For this purpose, the xylanase 11A gene of C. thermophilum was cloned in P. pastoris GS115 under the control of AOX1 promoter. The maximum extracellular activity of recombinant xylanase (xyn698: gene with intron) was 15.6 U ml−1 while that of recombinant without intron (xyn669) was 1.26 U ml−1 after 96 h growth. The gene product was purified apparently to homogeneity level. The optimum temperature of pure recombinant
xylanase activity was 70°C and the enzyme retained its 40.57% activity after incubation at 80°C for 10 min. It exhibited quite
lower demand of activation energy, enthalpy, Gibbs free energy, entropy, and xylan binding energy during substrate hydrolysis
than that required by that of the donor, thus indicating its thermostable nature. pH-dependent catalysis showed that it was
quite stable in a pH range of 5.5–8.5. This revealed that gene was successfully processed in P. pastoris and remained heat stable and may qualify for its potential use in paper and pulp and animal feed applications. 相似文献