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971.
Csaba Moskát Bengt Hansson Lilla Barabás István Bártol Zsolt Karcza 《Journal of avian biology》2008,39(6):663-671
In Hungary an unusually high rate of parasitism on the great reed warbler Acrocephalus arundinaceus by the common cuckoo Cuculus canorus has been maintained for at least the last one hundred years. We evaluated parasitism rate, antiparasite defence and genetic differentiation among Hungarian great reed warblers at three sites located 40–130 km from each other, where hosts suffered from a high (41–68%), moderate (11%), and almost no (<1%) parasitism. We were especially interested in whether the level of antiparasite defence was related to the local parasitism rate, and, if not, to understand why. There was no difference among the three sites in the responses to experimental parasitism by non‐mimetic model cuckoo eggs (rejection rate 71–82%), which can be explained by strong gene flow between populations: there was low level of philopatry and no genetic differentiation in the region. Reproductive success of the host in the heavily parasitised site was about 54% of that in the unparasitised site, indicating that long‐term persistence of host populations in highly exploited areas depends on continuous immigration. 相似文献
972.
Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis 总被引:6,自引:0,他引:6
973.
Máté Virágh Annamária Marton Csaba Vizler Liliána Tóth Csaba Vágvölgyi Florentine Marx László Galgóczy 《蛋白质与细胞》2015,6(7):518
Small, cysteine-rich, highly stable antifungal proteins secreted by filamentous Ascomycetes have great potential for the development of novel antifungal strategies. However, their practical application is still limited due to their not fully clarified mode of action. The aim of this work was to provide a deep insight into the antifungal mechanism of Neosartorya fischeri antifungal protein (NFAP), a novel representative of this protein group. Within a short exposure time to NFAP, reduced cellular metabolism, apoptosis induction, changes in the actin distribution and chitin deposition at the hyphal tip were observed in NFAP-sensitive Aspergillus nidulans. NFAP did show neither a direct membrane disruptingeffect nor uptake by endocytosis. Investigation of A. nidulans signalling mutants revealed that NFAP activates the cAMP/protein kinase A pathway via G-protein signalling which leads to apoptosis and inhibition of polar growth. In contrast, NFAP does not have any influence on the cell wall integrity pathway, but an unknown cell wall integrity pathway-independent mitogen activated protein kinase A-activated target is assumed to be involved in the cell death induction. Taken together, it was concluded that NFAP shows similarities, but also differences in its mode of antifungal action compared to two most investigated NFAP-related proteins from Aspergillus giganteus and Penicillium chrysogenum. 相似文献
974.
975.
SWI3 subunits of putative SWI/SNF chromatin-remodeling complexes play distinct roles during Arabidopsis development 下载免费PDF全文
Sarnowski TJ Ríos G Jásik J Swiezewski S Kaczanowski S Li Y Kwiatkowska A Pawlikowska K Koźbiał M Koźbiał P Koncz C Jerzmanowski A 《The Plant cell》2005,17(9):2454-2472
SWITCH/SUCROSE NONFERMENTING (SWI/SNF) chromatin-remodeling complexes mediate ATP-dependent alterations of DNA-histone contacts. The minimal functional core of conserved SWI/SNF complexes consists of a SWI2/SNF2 ATPase, SNF5, SWP73, and a pair of SWI3 subunits. Because of early duplication of the SWI3 gene family in plants, Arabidopsis thaliana encodes four SWI3-like proteins that show remarkable functional diversification. Whereas ATSWI3A and ATSWI3B form homodimers and heterodimers and interact with BSH/SNF5, ATSWI3C, and the flowering regulator FCA, ATSWI3D can only bind ATSWI3B in yeast two-hybrid assays. Mutations of ATSWI3A and ATSWI3B arrest embryo development at the globular stage. By a possible imprinting effect, the atswi3b mutations result in death for approximately half of both macrospores and microspores. Mutations in ATSWI3C cause semidwarf stature, inhibition of root elongation, leaf curling, aberrant stamen development, and reduced fertility. Plants carrying atswi3d mutations display severe dwarfism, alterations in the number and development of flower organs, and complete male and female sterility. These data indicate that, by possible contribution to the combinatorial assembly of different SWI/SNF complexes, the ATSWI3 proteins perform nonredundant regulatory functions that affect embryogenesis and both the vegetative and reproductive phases of plant development. 相似文献
976.
Androgenesis of wheat, rice and triticale was studied in isolated microspore culture. It is the first publication which studies microspore culture reaction of Hungarian rice varieties. The effect of different basic media, lack and absence of growth regulators in culture media were tested on important parameters of microspore culture. Direct embryogenesis was observed in microspore culture of wheat and triticale genotypes. In the case of rice, calli were induced in isolated rice microspore culture and haploid rice plantlets were regenerated via organogenesis.In wheat, the effect of basic media (W14, A2, CHB3, P4-m) was compared and among them the W14, and A2 had a superior effect on embryo production and albino and green plantlet regeneration. In rice the C, CHB3 and MSm media were tested in microspore culture and the significantly highest numbers of calli were achieved by using C and CHB3 media depending on the genotypes. The lack of exogenous growth regulators was observed in isolated microspore culture of triticale and rice. Growth regulator-free medium had a positive effect on embryo production and plant regeneration of triticale genotypes, whereas in rice microspore culture multicellular structures did not continue their division without growth regulators from the third week of microspore culture. Developing of microspore-origin calli was maintained by supplement of 2,4-D and Kinetin combination in the microspore culture medium. 相似文献
977.
Avilov SV Bode C Tolgyesi FG Klymchenko AS Fidy J Demchenko AP 《International journal of biological macromolecules》2005,36(5):290-298
The single Cys residue in the C-terminal domain of bovine eye lens alpha-crystallin was covalently labelled with 6-bromomethyl-2-(2-furanyl)-3-hydroxychromone. This novel SH-reactive two-band ratiometric fluorescent dye is characterized by excited state intramolecular proton transfer reaction yielding two highly emissive N* and T* bands separated by more than 100 nm. Their relative intensities are known to be highly sensitive to the H-bonding ability of the environment. Properties of the environment of the dye attached to the protein were studied under native-like conditions and at a range of elevated temperatures that are known to facilitate alpha-crystallin chaperone-like activity. We observe that on heating, the environment of the dye becomes more flexible and the H-bonding of the dye with the protein vicinity decreases. The spectroscopic properties observed on heating were partially restored after cooling, but the initial values were not reached on the time scale of our experiments (up to 3 h). This suggests that the changes of the dye microenvironment are connected with the rearrangements of alpha-crystallin quaternary structure. Since there is only one Cys residue in alphaA subunit of alpha-crystallin (whereas alphaB subunit contains no Cys), we attributed the observed temperature-induced changes of the dye's microenvironment to the particular site within alpha-crystallin molecule. 相似文献
978.
Swimbladder changes resulting from Anguillicola crassus infection of the European eel Anguilla anguilla have been the subject of several studies reported in the literature. These investigations, however, studied exclusively the status of infection at a given point in time and did not deal with changes in swimbladder infection in eels suffering from anguillicolosis over a period of time. In this study, A. crassus-induced pathological changes were monitored in 78 eels naturally infected in Lake Balaton and subsequently kept in the laboratory, thus excluding the possibility of further infection. During the 3 mo study, the status of the swimbladder was checked by radiographic examination on 4 occasions. At the end of the study the eels were dissected and the gross pathological changes in the swimbladders were compared with the radiographic findings. As compared to their starting condition, by the end of the study the pathological status of the swimbladder had deteriorated in 55% and remained the same in 37% of the cases. Tendency to improvement (1%) and variable findings (7%) were recorded in a low percentage of cases only. With the help of the radiographs presented, the dynamics of A. crassus infection and of changes in the swimbladder of individual eel specimens can be monitored easily. 相似文献
979.
beta-Adrenergic activation reveals impaired cardiac calcium handling at early stage of diabetes 总被引:2,自引:0,他引:2
op den Buijs J Miklós Z van Riel NA Prestia CM Szenczi O Tóth A Van der Vusse GJ Szabó C Ligeti L Ivanics T 《Life sciences》2005,76(10):1083-1098
Cardiac function is known to be impaired in diabetes. Alterations in intracellular calcium handling have been suggested to play a pivotal role. This study aimed to test the hypothesis that beta-adrenergic activation can reveal the functional derangements of intracellular calcium handling of the 4-week diabetic heart. Langendorff perfused hearts of 4-week streptozotocin-induced diabetic rats were subjected to the beta-adrenoceptor agonist isoproterenol. Cyclic changes in [Ca(2+)](i) levels were measured throughout the cardiac cycle using Indo-1 fluorescent dye. Based on the computational analysis of the [Ca(2+)](i) transient the kinetic parameters of the sarcoplasmic reticulum Ca(2+)-ATPase and the ryanodine receptor were determined by minimizing the squared error between the simulated and the experimentally obtained [Ca(2+)](i) transient. Under unchallenged conditions, hemodynamic parameters were comparable between control and diabetic hearts. Isoproterenol administration stimulated hemodynamic function to a greater extent in control than in diabetic hearts, which was exemplified by more pronounced increases in rate of pressure development and decline. Under unchallenged conditions, [Ca(2+)](i) amplitude and rate of rise and decline of [Ca(2+)](i) as measured throughout the cardiac cycle were comparable between diabetic and control hearts. Differences became apparent under beta-adrenoceptor stimulation. Upon beta-activation the rate-pressure product showed a blunted response, which was accompanied by a diminished rise in [Ca(2+)](i) amplitude in diabetic hearts. Computational analysis revealed a reduced function of the sarcoplasmic reticulum Ca(2+)-ATPase and Ca(2+)-release channel in response to beta-adrenoceptor challenge. Alterations in Ca(2+)(i) handling may play a causative role in depressed hemodynamic performance of the challenged heart at an early stage of diabetes. 相似文献
980.