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131.
Andrej Kormu?ák Seok-Woo Lee Kyung-Nak Hong Byeung-Hook Yang Yong-Pyo Hong 《Biologia》2008,63(1):94-99
Artificial crossing experiments involving 3 Abies species native to Korean peninsula and 5 other representatives of Abies revealed a high hybridological affinity between Abies koreana and A. nephrolepis. Both these species are reproductively isolated from A. holophylla. All the three Korean species were found to exhibit incompatible relationships with the North American species A. concolor. The species A. holophylla and A. koreana differ also in their abilities to intercross with the Mediterranean firs. The former has been successfully crossed with A. nordmanniana, A. alba and A. cilicica exhibiting 19.1–55.3% crossability, whereas the latter produced filled seeds only with A. nordmanniana reaching 46.4% crossability. A considerable differentiation is postulated to exist between the pair of species A. koreana and A. nephrolepis on the one side and A. holophylla on the other side. 相似文献
132.
Previously, two genes, designated as lyt and hol, were identified in the lysis module of phage μ1/6. They were cloned and expressed in Escherichia
coli. An additional candidate holin gene, hol2, was found downstream from the hol gene based on one predicted transmembrane domain and a highly charged C-terminal sequence of the encoded protein. Expression
of hol or hol2 in E. coli was shown to cause cell death. The concomitant expression of λ endolysin (R) and μ1/6 holin resulted in cell lysis. Similarly,
the coexpression of the endolysin and holin of phage μ1/6 led to lysis, apparently due to the ability of μ1/6 endolysin to
hydrolyze the peptidoglycan layer of this bacterium. In contrast, the simultaneous expression of μ1/6 hol2 and the endolysin gene (λR or μ1/6 lyt) did not cause detectable lysis of the host cells. Demonstration of the holin function in streptomycetes was achieved by
providing for the release of μ1/6 endolysin to the periplasm and subsequent cleavage of the peptidoglycan, which strongly
suggested that the holin produces lesions in the streptomycete membrane. 相似文献
133.
Andrej A. Romanovsky Alexandre A. Steiner Luiz G. S. Branco Ladislav Janský Valery N. Gourine 《Journal of thermal biology》2004,29(7-8):407-411
(1) Administration of arginine vasopressin (AVP) in the ventral septal area (VSA) or intracerebroventricularly (i.c.v.) is thought to attenuate lipopolysaccharide (LPS) or prostaglandin (PG) E2 fevers in rabbits and rats by acting on the V1 receptor. (2) We found that the fever response of rabbits to intravenous LPS (200 ng/kg) or intra-VSA PGE2 (500 ng) was not attenuated but enhanced by intra-VSA AVP (5 μg); a pharmacological analysis showed that this fever-enhancing effect was mediated by the V2 receptor. (3) The febrile response of rats to intraperitoneal (50 μg/kg) or i.c.v. (100 ng) LPS was unaffected by i.c.v. AVP (2.5–100 ng). (4) The role of AVP in fever should be re-examined. 相似文献
134.
Zai-Qing Liu Guo-Min Deng Simon Foster Andrej Tarkowski 《Arthritis research & therapy》2001,3(6):375-6
Staphylococcus aureus is one of the most important pathogens in septic arthritis. To analyse the arthritogenic properties of staphylococcal peptidoglycan (PGN), highly purified PGN from S. aureus was intra-articularly injected into murine joints. The results demonstrate that PGN will trigger arthritis in a dose-dependent manner. A single injection of this compound leads to massive infiltration of predominantly macrophages and polymorphonuclear cells with occasional signs of cartilage and/or bone destruction, lasting for at least 14 days. Further studies showed that this condition is mediated by the combined impact of acquired and innate immune systems. Our results indicate that PGN exerts a central role in joint inflammation triggered by S. aureus. 相似文献
135.
Ursula Pieper Narayanan Eswar Ashley C. Stuart Valentin A. Ilyin Andrej Sali 《Nucleic acids research》2002,30(1):255-259
MODBASE (http://guitar.rockefeller.edu/modbase) is a relational database of annotated comparative protein structure models for all available protein sequences matched to at least one known protein structure. The models are calculated by MODPIPE, an automated modeling pipeline that relies on PSI-BLAST, IMPALA and MODELLER. MODBASE uses the MySQL relational database management system for flexible and efficient querying, and the MODVIEW Netscape plugin for viewing and manipulating multiple sequences and structures. It is updated regularly to reflect the growth of the protein sequence and structure databases, as well as improvements in the software for calculating the models. For ease of access, MODBASE is organized into different datasets. The largest dataset contains models for domains in 304 517 out of 539 171 unique protein sequences in the complete TrEMBL database (23 March 2001); only models based on significant alignments (PSI-BLAST E-value < 10–4) and models assessed to have the correct fold are included. Other datasets include models for target selection and structure-based annotation by the New York Structural Genomics Research Consortium, models for prediction of genes in the Drosophila melanogaster genome, models for structure determination of several ribosomal particles and models calculated by the MODWEB comparative modeling web server. 相似文献
136.
Background The cost–benefit model for the evolution of botanical carnivory provides a conceptual framework for interpreting a wide range of comparative and experimental studies on carnivorous plants. This model assumes that the modified leaves called traps represent a significant cost for the plant, and this cost is outweighed by the benefits from increased nutrient uptake from prey, in terms of enhancing the rate of photosynthesis per unit leaf mass or area (AN) in the microsites inhabited by carnivorous plants.Scope This review summarizes results from the classical interpretation of the cost–benefit model for evolution of botanical carnivory and highlights the costs and benefits of active trapping mechanisms, including water pumping, electrical signalling and accumulation of jasmonates. Novel alternative sequestration strategies (utilization of leaf litter and faeces) in carnivorous plants are also discussed in the context of the cost–benefit model.Conclusions Traps of carnivorous plants have lower AN than leaves, and the leaves have higher AN after feeding. Prey digestion, water pumping and electrical signalling represent a significant carbon cost (as an increased rate of respiration, RD) for carnivorous plants. On the other hand, jasmonate accumulation during the digestive period and reprogramming of gene expression from growth and photosynthesis to prey digestion optimizes enzyme production in comparison with constitutive secretion. This inducibility may have evolved as a cost-saving strategy beneficial for carnivorous plants. The similarities between plant defence mechanisms and botanical carnivory are highlighted. 相似文献
137.
Andrej Meglič Gregor Zupančič 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2011,197(3):301-310
Time courses of mitochondrial responses to illumination-induced physiological loads and to hypoxia, were recorded optically
from eyes of blowflies Calliphora vicina chalky. We isolated changes in redox states of haems a3, a, c, and b. Two types of responses to light stimulation were observed. Haems b and a3 responded with transient oxidation and haems a and c with reduction. The same two groups emerged in response to anoxic exposure.
The onset of reduction of haems a and c had virtually no latency, while haems a3 and b exhibited a transient oxidation followed by reduction only after 10–20 s. The dependence of the steady-state reduction
level on
P\textO2 P_{{{\text{O}}_{2} }} produced the same groups. Haems a and c were significantly reduced at
P\textO2 P_{{{\text{O}}_{2} }} levels around 10 kPa while with haems b and a3 load-induced oxidation was only replaced by reduction below 2 kPa. We propose haems respond to physiological loads in accordance
with their steady-state reduction, which in turn depends largely on barriers for electron transport imposed by the mitochondrial
membrane potential. We also propose it may be possible to assess the values of tissue
P\textO2 P_{{{\text{O}}_{2} }} and O2 consumption by monitoring haems that are highly oxidized at rest such as haem a. 相似文献
138.
139.
Summary Two new shuttle promoter-probe vectors forE.coli andStreptomycetes were constructed. Plasmid vectors allow the cloning of promoter-carrying DNA fragments based on the resistance to neomycin and chloramphenicol both, inE.coli andStreptomycetes. Using these vectors several promoter regions active either inE.coli orS.lividans were identified from the actinophage DNA. 相似文献
140.