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1.
T. D. Dubatolova S. A. Kopyl N. A. Bulgakova N. V. Dorogova L. V. Omelyanchuk L.-Sh. Chang 《Russian Journal of Genetics》2010,46(2):164-169
Experiments on transplantation of wing imaginal discs homozygous for a mutation in the tumor suppressor gene Merlin have demonstrated that this mutation does not induce malignant tumors. Marking of the wing disc compartment borders by specific
antibodies showed the absence of essential compartment border defects in case of the Merlin mutation. Drosophila melanogaster cells mutant for Merlin have shorter cell cycle than normal cells. Proliferation of imaginal discs lasts longer in case of the mutation. It is known
that beginning from some moment of development, wing veins serve as clonal restriction lines that cannot be crossed by growing
mosaic clones. We showed that the Merlin mutation leads to depression of vein clonal restriction property. This means that this gene is involved not only in the control
of cell proliferation, but also in the control of cell mobility and adhesion. 相似文献
2.
Analysis with the polymerase chain reaction showed that the Khlorofill-4 pea Pisum sativum chlorophyll-deficient mutant with reduced stipules has an altered structure of the COCHLEATA (COCH) gene, carrying a new mutant COCH allele. The phenotype of the mutant was described in comparison with another form having reduced stipules (stipules reduced) and the control. Leaves of the coch mutant are smaller and have other proportions than in the control; stipules are absent from leaves of the first nodes and
are narrow, bandlike, or spoonlike at later ontogenetic stages. It was concluded that the cell number in the stipule epidermis
is reduced in the st and coch mutants compared to the wild type. 相似文献
3.
4.
Indeok Hwang Dilli Prasad Paudyal Seong-Ki Kim Hyeonsook Cheong 《Biotechnology and Bioprocess Engineering》2007,12(2):157-164
Inhibitors are very important in the study of hormone function. Brasinazole (Brz) is a specific inhibitor of brassinosteroids
(BRs) biosynthesis. To expand our knowledge of the molecular mechanisms of plant steroid signaling, we performed genetic screening
using medium containing Brz under dark conditions. Mutants insensitive to Brz developlonger hypocotyls than their wild type
counterparts. We isolatedabz453 as a Brz insensitive mutant. TAIL-PCR and the segregation ratio of T2 plants indicated a single T-DNA insertion at the 24-Sterol
C-methyltransferase (SMT2) gene in theabz453 mutant. Recapitulation for putative FCP serine phosphatase (FSP), the gene neighboringSMT2, indicated no significant phenotypes, but theSMT2 anti-sense (SMT2-AS) line developed longer hypocotyls than the wild type in medium containing Brz. Additionally, theSMT2-AS line displayed similar phenotypes to theabz453 line in soil including enhanced growth and smaller silique. Theabz453 andSMT2-AS mutants showed phenotypes similar to those of wild type in medium containing benzylaminopurine, pacrobutrazol and ACC (precursor
for ethylene) under dark conditions. However, when brassinolide (BL) dose response was observed, theabz453 andSMT2-AS lines showed higher sensitivity than wild type. Theabz453/det2 andabz453/bri1-119 double mutants showed enhanced growth compared to thedet2 andbri1-119 line under both dark and light conditions. Specially, in dark conditions double mutants displayed nearly 2- and 1.5-fold
longer hypocotyls thandet2 andbri1-119 plants. Brz insensitivity to theSMT2 knock-out mutant and phenotypes of double mutants indicate that not only do BRI1 and DET2 influence the BRs response, as
evidenced by hypocotyl elongation, but another sterol derived signals may also be affected in mutants, suggesting that another
pathway is involved in hypocotyl elongation due to SMT2. 相似文献
5.
S. A. Kopyl N. V. Dorogova E. M. Akhmametyeva L. V. Omelyanchuk L. -S. Chang 《Russian Journal of Genetics》2010,46(3):276-282
The protein Merlin is involved in the regulation of cell proliferation and differentiation in the eyes and wings of Drosophila and is a homolog of the human protein encoded by the Neurofibromatosis 2 (NF2) gene whose mutations cause auricular nerve tumors. Recent studies show that Merlin and Expanded cooperatively regulate the
recycling of membrane receptors, such as the epidermal growth factor receptor (EGFR). By performing a search for potential
genetic interactions between Merlin (Mer) and the genes important for vesicular trafficking, we found that ectopic expression in the wing pouch of the clathrin adapter
protein Lap involved in clathrin-mediated receptor endocytosis resulted in the formation of extra vein materials. On the one
hand, coexpression of wild-type Merlin and lap in the wing pouch restored normal venation, while overexpression of a dominant-negative mutant Mer
DBB
together with lap enhanced ectopic vein formation. Using various constructs with Merlin truncated copies, we showed the C-terminal portion
of the Merlin protein to be responsible for the Merlin-lap genetic interaction. Furthermore, we showed that the Merlin and Lap proteins colocalized at the cortex of the wing imaginal
disc cells. 相似文献
6.
An autolysin gene, atlh, was identified and sequenced from Streptococcus downei MFe28 using degenerate polymerase chain reaction (PCR) and the gene-walking method. Atlh protein encoded by atlh is composed of 879 amino acids, with a molecular weight of 95,902.26. Atlh possesses four 15-amino-acid residue repeats in
the putative cell-wall-binding domain and has a catalytic domain in the C-terminus. The deduced amino acid sequence of atlh showed homology to S. mutans autolysin AtlA (68.4% similarity). Inactivation of atlh resulted in elongated chain formation compared to the parent strain. Recombinant proteins Atlh and its derivatives were constructed
and analyzed by zymography. Zymographic analysis revealed that the Asp-771 residue of Atlh was essential for lytic activity
and that lytic activity was not diminished by the deletion of repetitive regions in the putative cell-wall-binding domain
of Atlh. Biofilm assay showed that the wild-type strain formed glucose- and sucrose-dependent biofilms, the atlh mutant diminished this ability. These results suggest that Atlh is associated with cell separation and biofilm formation. 相似文献
7.
Valentina Rosu Mark S Chadfield Antonella Santona Jens P Christensen Line E Thomsen Salvatore Rubino John E Olsen 《Acta veterinaria Scandinavica》2007,49(1):14
Background
Salmonella enterica serotype Gallinarum (S. Gallinarum) remains an important pathogen of poultry, especially in developing countries. There is a need to develop effective and safe vaccines. In the current study, the effect of crp deletion was investigated with respect to virulence and biochemical properties and the possible use of a deletion mutant as vaccine candidate was preliminarily tested. 相似文献8.
9.
To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans
gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold
than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration. 相似文献
10.
Ching-Nan Lin Wan-Jr Syu Wei-Sheng W Sun Jenn-Wei Chen Tai-Hung Chen Ming-Jaw Don Shao-Hung Wang 《Journal of biomedical science》2010,17(1):84
Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is not clear. Previous findings showed that plumbagin
treatment triggered up-regulation of many genes in E. coli including ahpC, mdaB, nfnB, nfo, sodA, yggX and ygfZ. By analyzing minimal inhibition concentration and inhibition zones of plumbagin in various gene-disruption mutants, ygfZ and sodA were found critical for the bacteria to resist plumbagin toxicity. We also found that the roles of YgfZ and SodA in detoxifying
plumbagin are independent of each other. This is because of the fact that ectopically expressed SodA reduced the superoxide
stress but not restore the resistance of bacteria when encountering plumbagin at the absence of ygfZ. On the other hand, an ectopically expressed YgfZ was unable to complement and failed to rescue the plumbagin resistance
when sodA was perturbed. Furthermore, mutagenesis analysis showed that residue Cys228 within YgfZ fingerprint region was critical for
the resistance of E. coli to plumbagin. By solvent extraction and HPLC analysis to follow the fate of the chemical, it was found that plumbagin vanished
apparently from the culture of YgfZ-expressing E. coli. A less toxic form, methylated plumbagin, which may represent one of the YgfZ-dependent metabolites, was found in the culture
supernatant of the wild type E. coli but not in the ΔygfZ mutant. Our results showed that the presence of ygfZ is not only critical for the E coli resistance to plumbagin but also facilitates the plumbagin degradation. 相似文献
11.
B. F. Chadov N. B. Fedorova E. V. Chadova E. A. Khotskina M. P. Moshkin D. V. Petrovski 《Russian Journal of Genetics》2010,46(9):1062-1066
Conditional dominant lethals (CDL) represent a special class of genetic mutations observed in Drosophila. Mutation manifests as a dominant lethal in one genotype, but lethality is not expressed in another genotype. CDL mutants
exhibit a set of traits discriminating them from classic mutations. We observed unusually high mobility of flies and high
sexual activity of males carrying these mutations. We used special tests for evaluation of energy metabolism of CDL mutants.
Indirect calorimetry (CO2 excretion measurement) has been used for estimation of energy exchange in four mutant and two control fly lines. A special
device has been used for evaluation of locomotor activity of these fly lines. Energy exchange and locomotor activity in CDL
mutants were significantly higher than in control lines. We conclude that some genetic mutations are capable of increasing
energy dissipation in their carriers. 相似文献
12.
Kamiel Spoelstra Serge Daan 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2008,194(3):235-242
Mutations in each of the genes mPer1, mPer2, mCry1 and mCry2 separately cause deviations from the wild type circadian system. Differences between these mutant strains have inspired the
hypothesis that the duality of circadian genes (two mPer and two mCry genes involved) is related to the existence of two components in the circadian oscillator (Daan et al., J Biol Rhythms 16:105–116,
2001). We tested the predictions from this theory that the circadian period (τ) lengthens under constant illumination (LL)
in mCry1 and mPer1 mutant mice, while it shortens in mCry2 and mPer2 mutants. mCry1
−/−
and mCry2
−/−
knockout mice both consistently increased τ with increasing light intensity, as did wild type mice. With increasing illumination,
rhythmicity is reduced in mCry1, mCry2 and mPer1, but not in mPer2 deficient mice. Results for mPer mutant mice are in agreement with data reported on these strains earlier by Steinlechner et al. (J Biol Rhythms 17:202–209,
2002), and also with the predictions from the model. The increase in cycle length of the circadian system by light in the
mCry2 deficient mice violates the predictions. The model is thereby rejected: the mCry genes do not play a differential role, although the opposite responses of mPer mutants to light remain consistent with a functional Evening–Morning differentiation. 相似文献
13.
Moslem Papizadeh Mohammad Roayaei Ardakani Gholamhossein Ebrahimipour Hossein Motamedi 《World journal of microbiology & biotechnology》2010,26(7):1195-1200
Oil-polluted soils were sampled from National Iranian South Oil Company (NISOC) for isolation and screening of C–S and not
C–C targeted Dibenzothiophene (DBT) degrading microorganisms. Microbacterium sp. NISOC-06, a C–S targeted DBT degrading bacterium, was selected and its desulfurization ability was studied in aqueous phase and water-gasoline
biphasic systems. The 16srRNA gene was amplified using universal eubacteria-specific primers, PCR product was sequenced and
the sequence of nearly 1,500 bp 16srDNA was studied. Based on Gas Chromatography results Microbacterium sp. NISOC-06 utilized 94.8% of 1 mM DBT during the 2 weeks of incubation. UV Spectrophotometry and biomass production measurements showed
that the Microbacterium sp. NISOC-06 was not able to utilize DBT as a carbon source. There was no accumulation of phenolic compounds as Gibb’s assay showed. Biomass
production in a biphasic system for which DBT-enriched gasoline was used as the sulfur source indicated the capability of
Microbacterium sp. NISOC-06 to desulfurize gasoline. 相似文献
14.
Hua Zhang Rui Xia Zhou Li Jing Zhang Ruo Yu Wang Li Zhe An 《Journal of Plant Biology》2007,50(3):336-343
A novel late embryogenesis abundant (LEA) gene (AY804193), namedCbLEA, has now been isolated fromChorispora bungeana. This rare alpine subnival plant can survive sudden snowstorms and low temperatures. The full-lengthCbLEA is 842 bp, with an open reading frame encoding 169 ami no acids. The putative molecular weight ofCbLEA protein is 17.9 kDa, with an estimatedpl of 6.45. To investigate the functioning of thisCbLEA protein in cold-stress tolerance,CbLEA was introduced into tobacco under the control of the CaMV35S promoter. Second-generation (R1) transgenic tobacco plants exhibited significantly increased tolerance to cold. These transgenics maintained lower malondialdehyde
(MDA) contents and electrolyte leakage (EL) but their relative water content (RWC) was significantly higher compared with
non-transgenic plants under chilling stress. Further experimental results showed that non-transgenic plants had severe freezing
damage after exposure to -2°C for 1 h, whereas the transgenics suffered only slight injury under the same conditions. Moreover,
survival was longer in the latter genotype at that temperature. The extent of increased cold tolerance was positive correlated
with the level ofCbLEA protein accumulation, and was also reflected by the delayed development of damage symptoms. This indicates thatCbLEA is an excellent stress tolerance gene, and holds considerable potential as a new molecular tool for engineering improved
plant genetics. 相似文献
15.
Background
Streptococcus gallolyticus subsp. gallolyticus is an important causative agent of infective endocarditis (IE) but the knowledge on virulence factors is limited and the pathogenesis of the infection is poorly understood. In the present study, we established an experimental in vitro IE cell culture model using EA.hy926 and HUVEC cells to investigate the adhesion and invasion characteristics of 23 Streptococcus gallolyticus subsp. gallolyticus strains from different origins (human IE-derived isolates, other human clinical isolates, animal isolates). Adhesion to eight components of the extracellular matrix (ECM) and the ability to form biofilms in vitro was examined in order to reveal features of S. gallolyticus subsp. gallolyticus endothelial infection. In addition, the strains were analyzed for the presence of the three virulence factors gtf, pilB, and fimB by PCR. 相似文献16.
S. Kumar Sunil Kumar S. P. Negi J. K. Kanwar 《In vitro cellular & developmental biology. Plant》2008,44(6):474-479
Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium
containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About
30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable
resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates. 相似文献
17.
Mycobacterium tuberculosis, the causative agent of tuberculosis, has a lipid-rich cell wall that serves as an effective barrier against drugs and toxic
host cell products, which may contribute to the organism’s persistence in a host. M. tuberculosis contains four homologous operons called nice (mce1–4) that encode putative ABC transporters involved in lipid importation across the cell wall. Here, we analyzed the lipid composition
of M. tuberculosis disrupted in the mce2 operon. High resolution mass spectrometric and thin layer chromatographic analyses of the mutant’s cell wall lipid extracts
showed accumulation of SL-1 and SL1278 molecules. Radiographic quantitative analysis and densitometry revealed 2.9, 3.9 and 9.8-fold greater amount of [35S] SL-1 in the mce2 operon mutant compared to the wild type M. tuberculosis during the early/mid logarithmic, late logarithmic and stationary phase of growth in liquid broth, respectively. The amount
of [35S] SL1278 in the mutant also increased progressively over the same growth phases. The expression of the mce2 operon genes in the wild type strain progressively increased from the logarithmic to the stationary phase of bacterial growth
in vitro, which inversely correlated with the proportion of radiolabel incorporation into SL-1 and SL1278 at these phases. Since the mce2 operon is regulated in wild type M. tuberculosis, its cell wall may undergo changes in SL-1 and SL1278 contents during a natural course of infection and this may serve as an important adaptive strategy for M. tuberculosis to maintain persistence in a host. 相似文献
18.
Qin Xue Jie Sun Mingwen Zhao Keyun Zhang Ren Lai 《World journal of microbiology & biotechnology》2011,27(5):1017-1023
A 17-kDa water-soluble polysaccharide (PB) was isolated and purified from Phellinus baumii using the DEAE-Sephadex A-50 and LPLC-Sephadex G-75 methods. Exposure of RAW264.7 macrophages to PB resulted in a significant
increase of the cellular proliferation rate, nitric oxide production and expression levels of the IL-1β, IL-18, IL-6, IL-12p35
and IL-12p40 genes. An MTT assay indicated that PB markedly suppressed the proliferation of HepG2 human liver cancer cells in a dose-dependent manner. Cell cycle analysis demonstrated that PB caused cell cycle arrest at
the S phase, and 400 μg/ml of PB induced apoptotic cell death in HepG2 cells after 48 h. The results suggested that PB inhibited the proliferation of HepG2 cells by inducing cell cycle arrest at S phase, leading to apoptosis. In summary, our data indicate that the PB exerts immunoregulatory
and anti-tumor activities in vitro. 相似文献
19.
Jesús Aranda Margarita Poza Belén G Pardo Soraya Rumbo Carlos Rumbo José R Parreira Patricia Rodríguez-Velo Germán Bou 《BMC microbiology》2010,10(1):279
Background
Acinetobacter baumannii is a multidrug-resistant bacterium responsible for nosocomial infections in hospitals worldwide. Study of mutant phenotypes is fundamental for understanding gene function. The methodologies developed to inactivate A. baumannii genes are complicated and time-consuming; sometimes result in unstable mutants, and do not enable construction of double (or more) gene knockout mutant strains of A. baumannii. 相似文献20.
D. V. Fedorov S. V. Kovaltzova V. T. Peshekhonov V. G. Korolev 《Russian Journal of Genetics》2010,46(6):659-665
The yeast genes IXR1 and HMO1 encode proteins belonging to the family of chromatin nonhistone proteins, which are able to recognize and bind to irregular
DNA structures. The full deletion of gene IXR1 leads to an increase in cell resistance to the lethal action of UV light, γ-rays, and MMS, increases spontaneous mutagenesis and significantlly decreases the level of UV-induced mutations. It was earlier
demonstrated in our works that the hmo1 mutation renders cells sensitive to the lethal action of cisplatin and virtually does not affect the sensitivity to UV light.
Characteristically, the rates of spontaneous and UV-induced mutagenesis in the mutant are increased. Epistatic analysis of
the double mutation hmo1 ixr1 demonstrated that the interaction of these genes in relation to the lethal effect of cisplatin and UV light, as well as UV-induced
mutagenesis, is additive. This suggests that the products of genes HMO1 and IXR1 participate in different repair pathways. The ixr1 mutation significantly increases the rate of spontaneous mutagenesis mediated by replication errors, whereas mutation hmo1 increases the rate of repair mutagenesis. In wild-type cells, the level of spontaneous mutagenesis was nearly one order of
magnitude lower than that obtained in cells of the double mutant. Consequently, the combined activity of the Hmo1 and the
Ixr1 proteins provides efficient correction of both repair and replication errors. 相似文献