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1.
Susanne Niemann-Seyde Ryszard Slomski Frauke Rininsland Ute Ellermeyer Jolanta Kwiatkowska Jochen Reiss 《Human genetics》1992,90(1-2):65-70
Summary A total of 56 Duchenne muscular dystrophy (DMD) patients and 11 Becker muscular dystrophy (BMD) patients was analyzed by extended multiplex amplification of the DMD/BMD gene; deletions were found in 60% of these patients. The data obtained were used to test the frameshift hypothesis and to compare the distribution of familial versus isolated cases. A significant correlation was found between deletions and isolated cases. Additional experiments were performed in order to determine the deletion breakpoints more precisely. These data are a prerequisite for carrier analysis in the respective families by detection or exclusion of aberrant cDNA fragments derived from ectopic lymphocyte RNA. This diagnostic technique is illustrated by 5 examples. 相似文献
2.
Jadwiga Jaruzelska Karen Friis Henriksen Flemming Güttler Olaf Riess Krzysztof Borski Nikolaus Blin Ryszard Slomski 《Human genetics》1991,86(3):247-250
Summary The incidence of phenylketonuria (PKU) in the western part of Poland is 1 in 5000 live births. Restriction fragment length polymorphism (RFLP) haplotypes at the phenylalanine hydroxylase locus have been analysed in 46 Polish families with PKU. Among 43 fully-informative families 16 RFLP haplotypes were identified. Haplotype 2 is the most frequently (62%) associated with Polish PKU alleles, and the codon 408 mutation is in complete linkage disequilibrium with this haplotype in Poland. This finding is in agreement with observations in other eastern European countries (German Democratic Republic, Czechoslovakia, and Hungary) and in contrast to the genotype distribution observed in western European countries. The present observation suggests the spread of classical PKU, due to the codon 408 mutation associated with haplotype 2, from east to west in European populations. Perhaps more important for genetic counselling, 62% of all PKU chromosomes in the Polish population can now be detected using only one mutantspecific oligonucleotide probe. 相似文献
3.
Stability of XGCGCp, GCGCYp, and XGCGCYp helixes: an empirical estimate of the energetics of hydrogen bonds in nucleic acids 总被引:8,自引:0,他引:8
S M Freier N Sugimoto A Sinclair D Alkema T Neilson R Kierzek M H Caruthers D H Turner 《Biochemistry》1986,25(11):3214-3219
The stabilizing effects of dangling ends and terminal base pairs on the core helix GCGC are reported. Enthalpy and entropy changes of helix formation were measured spectrophotometrically for AGCGCU, UGCGCA, GGCGCCp, CGCGCGp, and the corresponding pentamers XGCGCp and GCGCYp containing the GCGC core plus a dangling end. Each 5' dangling end increases helix stability at 37 degrees C roughly 0.2 kcal/mol and each 3' end from 0.8 to 1.7 kcal/mol. The free energy increments for dangling ends on GCGC are similar to the corresponding increments reported for the GGCC core [Freier, S. M., Alkema, D., Sinclair, A., Neilson, T., & Turner, D. H. (1985) Biochemistry 24, 4533-4539], indicating a nearest-neighbor model is adequate for prediction of stabilization due to dangling ends. Nearest-neighbor parameters for prediction of the free energy effects of adding dangling ends and terminal base pairs next to G.C pairs are presented. Comparison of these free energy changes is used to partition the free energy of base pair formation into contributions of "stacking" and "pairing". If pairing contributions are due to hydrogen bonding, the results suggest stacking and hydrogen bonding make roughly comparable favorable contributions to the stability of a terminal base pair. The free energy increment associated with forming a hydrogen bond is estimated to be -1 kcal/mol of hydrogen bond. 相似文献
4.
Polymer-supported RNA synthesis and its application to test the nearest-neighbor model for duplex stability 总被引:19,自引:0,他引:19
R Kierzek M H Caruthers C E Longfellow D Swinton D H Turner S M Freier 《Biochemistry》1986,25(24):7840-7846
A solid-phase method using a phosphoramidite approach is described for synthesis of oligoribonucleotides. The method was used to synthesize pairs of oligomers with identical nearest neighbors but different sequences. Comparison of thermodynamic parameters for these pairs provides a test of the nearest-neighbor hypothesis for prediction of helix stability. In general, pairs of sequences with identical nearest neighbors have enthalpy and entropy changes for helix formation that differ by 8% on average, delta Go37 that differ by 6% on average, and melting temperatures within 0-5 degrees C of each other. These limits are typical of the accuracy that should be expected from nearest-neighbor predictions of RNA helix stability. UCAUGA and UGAUCA have the same nearest neighbors but melting temperatures that differ by 7 degrees C. This suggests some sequences will not be approximated well by the nearest-neighbor model. 相似文献
5.
Seasonal changes of the photosynthetic capacity of the Antarctic macroalga Adenocystis utricularis (Bory) Skottsberg 总被引:1,自引:1,他引:0
Summary Photosynthetic oxygen evolution from Antarctic macroalgaAdenocystis utricularis, collected from littoral zone of Admiralty Bay of King George Island (South Shetland), was measured under standard laboratory conditions during a 9-month study period. During autumn and winter the photosynthetic apparatus of the alga revealed an increased capacity to use low irradiance. This coincided with increasing concentrations of chlorophyll a+c. In parallel respiration rates measured at the average monthly water temperature were lower in winter than in summer. 相似文献
6.
Possible mechanisms of afterripening in Xanthium seeds 总被引:1,自引:0,他引:1
Yohji Esashi Maria Ogasawara Ryszard Górecki A. Carl Leopold 《Physiologia plantarum》1993,87(3):359-364
Breaking dormancy in some seeds requires a period of dry storage. In the seeds of Xanthium pennsylvanicum Wallr., the process of afterripening proceeds optimally at water contents between 7 and 14%: this range of dehydration can be identified with water binding region 2, in which water is bound with low enthalpy. At water contents below 7%. Seeds remained primarily dormant over 3 years. Attempts to alter the afterripening with atmospheres of elevated nitrogen showed no effect. and with oxygen there was no consistent effect. There were no changes is osmotic value of the seed sap, or in its sugar or amino acid contents. We speculate that afterripening in Xanthium may involve some nonenxymatic reactions which remove substances which inhibit germination. Candidates for these reactions include the Amadori and Maillard reactions. 相似文献
7.
Yasushi Sato Munetaka Sugiyama Ryszard J. Górecki Hiroo Fukuda Atsushi Komamine 《Planta》1993,189(4):584-589
In a culture system in which single cells isolated from the mesophyll of Zinnia elegans L. differentiate to tracheary elements (TEs), two inhibitors of phenylalanine ammonia-lyase (EC 4.3.1.5), L-α-aminooxy-β-phenylpropionic acid (AOPP) at 10 μM inhibited lignification without reducing the number of TEs formed. These inhibitors caused intracellular changes in peroxidase (EC 1.11.1.7) activities. The inhibitors increased the activity of peroxidases bound to the cell walls and especially the activity of peroxidase bound ionically to the cell walls. In contrast, the activity of extracellular peroxidase decreased. There were five isoenzymes, P1-P5, in the ionically bound peroxidase of cultured Zinnia cells. Among the isoenzymes, P4 and P5 appeared to be specific for TE differentation. Treatment with AOPP and AIP resulted in increases in the activities of P2, P4 and P5 isoenzymes, with the most prominent increase in P5 activity. The addition of lignin precursors, including coniferyl alcohol, to the AOPP-treated cells restored lignification, and suppressed the alteration of peroxidase isoenzyme patterns caused by AOPP. The relationship between the wall-bound peroxidases and lignification during TE differentiation is discussed in the light of these results. 相似文献
8.
Jan Tumajer Krešimir Begović Vojtěch Čada Michal Jenicek Jelena Lange Jiří Mašek Ryszard J. Kaczka Miloš Rydval Miroslav Svoboda Lukáš Vlček Václav Treml 《Global Change Biology》2023,29(2):462-476
Radial tree growth is sensitive to environmental conditions, making observed growth increments an important indicator of climate change effects on forest growth. However, unprecedented climate variability could lead to non-stationarity, that is, a decoupling of tree growth responses from climate over time, potentially inducing biases in climate reconstructions and forest growth projections. Little is known about whether and to what extent environmental conditions, species, and model type and resolution affect the occurrence and magnitude of non-stationarity. To systematically assess potential drivers of non-stationarity, we compiled tree-ring width chronologies of two conifer species, Picea abies and Pinus sylvestris, distributed across cold, dry, and mixed climates. We analyzed 147 sites across the Europe including the distribution margins of these species as well as moderate sites. We calibrated four numerical models (linear vs. non-linear, daily vs. monthly resolution) to simulate growth chronologies based on temperature and soil moisture data. Climate–growth models were tested in independent verification periods to quantify their non-stationarity, which was assessed based on bootstrapped transfer function stability tests. The degree of non-stationarity varied between species, site climatic conditions, and models. Chronologies of P. sylvestris showed stronger non-stationarity compared with Picea abies stands with a high degree of stationarity. Sites with mixed climatic signals were most affected by non-stationarity compared with sites sampled at cold and dry species distribution margins. Moreover, linear models with daily resolution exhibited greater non-stationarity compared with monthly-resolved non-linear models. We conclude that non-stationarity in climate–growth responses is a multifactorial phenomenon driven by the interaction of site climatic conditions, tree species, and methodological features of the modeling approach. Given the existence of multiple drivers and the frequent occurrence of non-stationarity, we recommend that temporal non-stationarity rather than stationarity should be considered as the baseline model of climate–growth response for temperate forests. 相似文献
9.
Ryszard Russa Teresa Urbanik-Sypniewska Kristina Lindström Hubert Mayer 《Archives of microbiology》1995,163(5):345-351
Phenol-water extraction of Rhizobium loti NZP2213 cells allowed a simultaneous isolation of two structurally different lipopolysaccharides, from the aqueous (LPS-W) and phenol (LPS-P) phase that differed in their sodium doexycholate-PAGE pattern and composition. LPS-W showed a profile indicating an R-type LPS; LPS-P had a cluster of poorly resolved bands in the high-molecular-weight region. LPS-P contained large amounts of 6-deoxy-l-talose (6dTal), and a small amount of 2-O-methyl-6-deoxy-talose (molar ratio 30:1), both of which were completely absent in LPS-W. Methylation analysis gave only one major product, 2,4-di-O-methyl-6dTal, indicating that the O-chain is composed of a homopolymer of 1,3-linked 6dTal, having the methylated 6dTal (2-O-me-6dTal) probably localized at the non-reducing end of the O-chain. This homopolymeric O-chain was additionally O-acetylated, as evidenced by GC-MS and by 13C NMR analysis. The lipid A moieties of both LPS-W and LPS-P showed almost identical composition, with six, different 3-OH fatty acids and with two, so far not described, long-chain 4-oxo-fatty acids, all being amide-linked, and with 27-OH-28:0 as the main ester-linked fatty acid. Lipid A was of the lipid ADAG-type, i.e., having a (phosphorylated) 2,3-diamino-2,3-dideoxy-d-glucose-containing lipid A backbone. Lipid ADAG is widespread among species of the -2 group of Proteobacteria, but has so far not been encountered in any other rhizobial or agrobacterial species. 相似文献
10.
Dorothy E. Pumo Ryszard Wierzbicki Adrienne Sainten Jen-Fu Chiu 《Molecular and cellular biochemistry》1980,32(1):49-53
Summary Specific antisera were produced against chicken reticulocyte dehistonized chromatin. The antisera reacts strongly with chicken reticulocyte chromatin, but only marginally with chicken erythrocyte chromatin. There is no reticulocyte antigen detected in chicken liver. Reticulocyte maturation is accompanied by a gradual decrease in the chromatin immunological activity and template capacity. The reduction of immunological activity is due to the change of chromatin conformation during erythrocyte maturation. Dehistonization and sonication of erythrocyte chromatin raises the erythrocyte chromatin immunological activity to levels similar to those of reticulocyte chromatin. The erythrocyte nuclear antigens are class specific, not being found in frog erythroid cell or murine Friend leukemia cell chromatins. 相似文献