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101.
Molecular phylogeny and historical biogeography of the Holarctic wetland leaf beetle of the genus Plateumaris 总被引:1,自引:0,他引:1
Leaf beetles of the genus Plateumaris inhabit wetlands across the temperate zone of the Holarctic region. To explore the phylogeographic relationships among North American, East Asian, and European members of this genus and the origin of the species endemic to Japan, we studied the molecular phylogeny of 20 of the 27 species in this genus using partial sequences of mitochondrial cytochrome oxidase subunit I (COI) and the 16S and nuclear 28S rRNA genes. The molecular phylogeny revealed that three species endemic to Europe are monophyletic and sister to the remaining 11 North American and six Asian species. Within the latter clade, North American and Asian species did not show reciprocal monophyly. Dispersal-vicariance analysis and divergence time estimation revealed that the European and North America-Asian lineages diverged during the Eocene. Moreover, subsequent differentiation occurred repeatedly between North American and Asian species, which was facilitated by three dispersal events from North America to Asia and one in the opposite direction during the late Eocene through the late Miocene. Two Japanese endemics originated from different divergence events; one differentiated from the mainland lineage after differentiation from the North American lineage, whereas the other showed a deep coalescence from the North American lineage with no present-day sister species on the East Asian mainland. This study of extant insects provides molecular phylogenetic evidence for ancient vicariance between Europe and East Asia-North America, and for more recent (but pre-Pleistocene) faunal exchanges between East Asia and North America. 相似文献
102.
103.
Símová S Klíma M Cermak L Sourková V Andera L 《Apoptosis : an international journal on programmed cell death》2008,13(3):423-436
TRAIL, a ligand of the TNFα family, induces upon binding to its pro-death receptors TRAIL-R1/DR4 and TRAIL-R2/DR5 the apoptosis
of cancer cells. Activated receptors incite the formation of the Death-Inducing Signaling Complex followed by the activation
of the downstream apoptotic signaling. TRAIL-induced apoptosis is regulated at multiple levels, one of them being the presence
and relative number of TRAIL pro- and anti-apoptotic receptors on the cytoplasmic membrane. In a yeast two-hybrid search for
proteins that interact with the intracellular part (ICP) of DR4, we picked ARAP1, an adapter protein with ArfGAP and RhoGAP
activities. In yeast, DR4(ICP) interacts with the alternatively spliced ARAP1 lacking 11 amino acids from the PH5 domain.
Transfected ARAP1 co-precipitates with DR4 and co-localizes with it in the endoplasmic reticulum/Golgi, at the cytoplasmic
membrane and in early endosomes of TRAIL-treated cells. ARAP1 knockdown significantly compromises the localization of DR4
at the cell surface of several tumor cell lines and slows down their TRAIL-induced death. ARAP1 overexpressed in HEL cells
does not affect their TRAIL-induced apoptosis or the membrane localization of DR4, but it enhances the cell-surface presentation
of phosphatidyl serine. Our data indicate that ARAP1 is likely involved in the regulation of the cell-specific trafficking
of DR4 and might thus affect the efficacy of TRAIL-induced apoptosis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
104.
Ladislav Planka Petr Gal Helga Kecova Jiri Klima Jana Hlucilova Eva Filova Evzen Amler Petr Krupa Leos Kren Robert Srnec Lucie Urbanova Jana Lorenzova Alois Necas 《BMC biotechnology》2008,8(1):1-9
Background
Serum and high ionic strength solutions constitute important barriers to cationic lipid-mediated intravenous gene transfer. Preparation or incubation of lipoplexes in these media results in alteration of their biophysical properties, generally leading to a decrease in transfection efficiency. Accurate quantification of these changes is of paramount importance for the success of lipoplex-mediated gene transfer in vivo.Results
In this work, a novel time-resolved fluorescence resonance energy transfer (FRET) methodology was used to monitor lipoplex structural changes in the presence of phosphate-buffered saline solution (PBS) and fetal bovine serum. 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)/pDNA lipoplexes, prepared in high and low ionic strength solutions, are compared in terms of complexation efficiency. Lipoplexes prepared in PBS show lower complexation efficiencies when compared to lipoplexes prepared in low ionic strength buffer followed by addition of PBS. Moreover, when serum is added to the referred formulation no significant effect on the complexation efficiency was observed. In physiological saline solutions and serum, a multilamellar arrangement of the lipoplexes is maintained, with reduced spacing distances between the FRET probes, relative to those in low ionic strength medium.Conclusion
The time-resolved FRET methodology described in this work allowed us to monitor stability and characterize quantitatively the structural changes (variations in interchromophore spacing distances and complexation efficiencies) undergone by DOTAP/DNA complexes in high ionic strength solutions and in presence of serum, as well as to determine the minimum amount of potentially cytotoxic cationic lipid necessary for complete coverage of DNA. This constitutes essential information regarding thoughtful design of future in vivo applications. 相似文献105.
Kvasnica M Budesinsky M Swaczynova J Pouzar V Kohout L 《Bioorganic & medicinal chemistry》2008,16(7):3704-3713
Twelve steroidal platinum(II) complexes were synthesized by reaction of potassium tetrachloroplatinate with steroidal esters of L-methionine and L-histidine. The steroidal esters coordinated as bidentate ligands via S and N donor atoms of L-methionine and via two N donor atoms of L-histidine. Cholesterol, cholestanol, diosgenine, pregnenolone, dehydroepiandrosterone, testosterone, estrone, and estradiol were used as the steroidal compounds. The esters and complexes prepared were characterized by infrared, mass, and (1)H NMR spectroscopy and elemental analysis. Platinum complexes were tested for in vitro cytotoxicity against several cancer cell lines: T-lymphoblastic leukemia CEM, breast carcinoma MCF-7, lung carcinoma A-549, multiple myeloma RPMI 8226, and one normal cell line human fibroblast BJ. 相似文献
106.
Vladimir Balik Peter Mirossay Peter Bohus Igor Sulla Ladislav Mirossay Marek Sarissky 《Cellular and molecular neurobiology》2009,29(6-7):845-858
Glioblastoma multiforme (GBM) represents an extremely chemoresistant tumour type. Here, authors analysed the immunophenotype of GBM tumours by flow cytometry and correlated the immunophenotypic characteristics with sensitivity to chemotherapy. The expression of selected neural and non-neural differentiation markers including A2B5, CD34, CD45, CD56, CD117, CD133, EGFR, GFAP, Her-2/neu, LIFR, nestin, NGFR, Pgp and vimentin was analysed by flow cytometry in eleven GBM (WHO gr.IV) patients. The sensitivity of tumour cells to a panel of chemotherapeutic agents was tested by the MTT assay. All tumours were positive for A2B5, CD56, nestin and vimentin. CD133, EGFR, LIFR, NGFR and Pgp were expressed only by minor tumour cell subpopulations. CD34, CD45, CD117, GFAP and Her-2/neu were constantly negative. Direct correlations were found between the immunophenotypic markers and chemosensitivity: A2B5 vs lomustine (r2 = 0.642, P = 0.033), CD56 vs cisplatin (r2 = 0.745, P = 0.013), %Pgp+ vs vincristine (r2 = 0.846, P = 0.008), and %NGFR+ vs daunorubicine (r2 = 0.672, P = 0.047) and topotecan (r2 = 0.792, P = 0.011). In contrast, inverse correlations were observed between: EGFR vs paclitaxel (r2 = ?0.676, P = 0.046), CD133 vs dacarbazine (r2 = ?0.636, P = 0.048) and LIFR vs daunorubicine (r2 = ?0.878, P = 0.004). Finally, significant associations were also found among sensitivities to different chemotherapeutic agents and among different immunophenotypic markers. In conclusion, histopathologically identical GBM tumours displayed a marked immunophenotypic heterogeneity. The expression of A2B5, CD56, NGFR and Pgp appeared to be associated with chemoresistance whereas CD133, EGFR and LIFR expression was characteristic of chemosensitive tumours. We suggest that flow cytometric imunophenotypic analysis of GBM may predict chemoresponsiveness and help to identify patients who could potentially benefit from chemotherapy. 相似文献
107.
Ladislav Tamás Katarína Ďurčeková Jana Huttová Igor Mistrík 《Acta Physiologiae Plantarum》2009,31(1):139-144
The expression of defence-related peroxidases Prx7 and Prx8 in barley roots grown under selected abiotic stress conditions
(toxic metals: Cd, Al, Co, Cu, Hg; drought, salinity, extreme temperatures: heat, cold) and compounds activating (2,4-D) or
inhibiting (SHAM) POD activity as well as H2O2 and H2O2 scavenger (DTT) was characterized. Strong Cd concentration dependent expression of Prx8 peroxidase gene was observed, which
correlated with root growth inhibition induced by Cd- and some other stress factors (heavy metals, heat and salinity). Application
of H2O2 did not cause changes in expression of Prx8, but H2O2 scavenger (DTT) as well as the inhibitor (SHAM) and the activator (2,4-D) of PODs induced increase in Prx8 expression. Our
results demonstrate that root growth inhibition during any disturbance of active oxygen species (AOS) in root tissue is correlated
with up-regulation of Prx8 gene expression in barley roots. 相似文献
108.
A detailed analysis of Rhaponticum carthamoides (Willd.) Iljin root essential oil was carried out by GC, GC-MS and GC-FTIR techniques. In total, 30 components were identified, accounting for 98.0% of total volatiles. A norsesquiterpene 13-norcypera-1(5),11(12)-diene (22.6%), followed by aplotaxene (21.2%) and cyperene (17.9%), were isolated and their structures confirmed by 1D and 2D-NMR spectra (COSY, ROESY, HSQC, HMBC and INADEQUATE). Selinene type sesquiterpenes and aliphatic hydrocarbons were among minor constituents of the essential oil. The oil exhibited antimicrobial activity against 5 of 9 strains of bacteria and yeast, when tested using broth micro-dilution method. Minimum inhibitory concentrations ranged between 32 and 256 μg/ml. 相似文献
109.
110.
Molnarova Z Machatkova M Machal L Horakova J Hanzalova K 《Zygote (Cambridge, England)》2006,14(1):63-69
The aim of the work was to study a potential relationship between acrosome response characteristics of bovine spermatozoa and their ability to fertilize oocytes and produce in vitro embryos. Sperm of artificial insemination bulls with a high rate (22.0 +/- 4.1%, group A, n = 7) or a low rate (10.3 +/- 4.1%, group B, n = 8) of embryos were used. For acrosome assessment, motile spermatozoa from a Percoll gradient were incubated with or without heparin and examined by the fix-vital sperm assay (FVSA). The differences between the heparin-treated (H+) and the non-treated (H-) spermatozoa were significant (p < 0.01) in all bulls at all tested intervals. According to the kinetics of the heparin response, the bulls fell into three categories: fast (FR, n = 7), moderate (MR, n = 5) or slow (SR, n = 3) acrosome responses (p < 0.01). Five MR bulls were found in group A in comparison with two MR bulls in group B (57.1 vs 12.5%; p < 0.05). Intensity of the acrosome response (response index) was significantly higher in bull group A compared with bull group B (7.0 vs 4.6, p < 0.01). A positive correlation was recorded between response index and embryo rate (r = 0.668, p < 0.01). In conclusion (a) the kinetics of spermatozoa response to heparin may be important for in vitro fertilization, bulls with a moderate response appearing to be most suitable for embryo production; (b) greater spermatozoa response to heparin was related to more effective embryo production. 相似文献