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121.
Książczyk T Apolinarska B Kulak-Książczyk S Wiśniewska H Stojałowski S Łapiński M 《Journal of applied genetics》2011,52(3):305-311
Genome modifications that occur at the initial interspecific hybridization event are dynamic and can be consolidated during
the process of stabilization in successive generations of allopolyploids. This study identifies the number and chromosomal
location of ribosomal DNA (rDNA) sites between Secale cereale, Dasypyrum villosum, and their allotetraploid S. cereale × D. villosum hybrids. For the first time, we show the advantages of FISH to reveal chromosome rearrangements in the tetraploid Secale × Dasypyrum hybrids. Based on the specific hybridization patterns of ribosomal 5S, 35S DNA and rye species-specific pSc200 DNA probes,
a set of genotypes with numerous Secale/Dasypyrum translocations of 1R/1V chromosomes were identified in successive generations of allotetraploid S. cereale × D. villosum hybrids. In addition we analyse rye chromosome pairs using FISH with chromosome-specific DNA sequences on S. cereale × D. villosum hybrids. 相似文献
122.
Staniłsaw Grzesiak Tomasz Hura Maciej T. Grzesiak Sebastian Pieńkowski 《Acta Physiologiae Plantarum》1999,21(3):305-315
Effects of soil drought or waterlogging on the morphological traits of the root system and internal root anatomy were studied
in maize hybrids of different drought tolerance. The investigations comprised quantitative and qualitative analyses of a developed
plant root system through determining the number, length and dry matter of the particular components of the root system and
some traits of the anatomical structure of the seminal root. Obtained results have demonstrated a relatively broad variation
in the habit of the root system. This mainly refers, to the number, length and dry matter of lateral roots, developed by seminal
root, seminal adventitious and nodal roots as well as to some anatomical properties of the stele, cortex and metaxylem elements.
Plants grown under waterlogging or drought conditions showed a smaller number and less dry matter of lateral branching than
plants grown in control conditions. The harmful effect of waterlogging conditions on the growth of roots was greater when
compared with that of plants exposed to drought. In the measurements of the root morphological traits, the effect of soil
drought on the internal root anatomical characteristic was weaker than the effect of soil waterlogging. The observed effects
of both treatments were more distinct in a drought sensitive hybrid Pioneer D than in drought resistant Pioneer C one. The
drought resistant hybrid Pioneer C distinguished by a more extensive rooting and by smaller alterations in the root morphology
caused by the stress conditions than drought sensitive hybrid Pioneer D one. Also the differences between the resistant and
the sensitive maize hybrids were apparent for examined root anatomical traits. Results confirm that the hybrid Pioneer D of
a high drought susceptibility was found to be also more sensitive to periodieal soil water excess. A more efficient water
use and a lower shoot to root (S:R) ratio were found to be major reasons for a higher stress resistance of the hybrid Pioneer
C.
The reasons for a different response of the examined hybrids to the conditions of drought or waterlogging may be a more economical
water balance and more favourable relations between the shoot and root dimensions in the drought resistant genotype. The observed
modifications of the internal root structure caused by water deficit in plant tissues may partly influence on water conductivity
and transport within roots.
The results suggest that the morphological and anatomical traits of the maize root system may be used in practice as direct
or indirect selection criteria in maize breeding. 相似文献
123.
Breaking the apple embryo dormancy by nitric oxide involves the stimulation of ethylene production 总被引:4,自引:0,他引:4
Mature seeds of apple (Mallus domestica Borb. cv. Antonówka) are dormant and do not germinate unless their dormancy is removed by several weeks of moist-cold treatment.
We investigated the effect of short-term (3 h) nitric oxide (NO) pretreatment on breaking of apple embryonic dormancy expressed
as inhibition of germination and morphological abnormalities of young seedlings. Imbibition of embryos isolated from dormant
apple seeds with sodium nitroprusside (SNP) or S-nitroso,N-acetyl penicillamine (SNAP) as NO donors resulted in enhanced germination. Moreover, NO treatment removed morphological abnormalities
of seedlings developing from dormant embryo. The NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-teramethylimidazoline-1-oxyl-3 oxide
(cPTIO) removed the above effects. NO-mediated breaking of embryonic dormancy correlated well with enhanced ethylene production.
Inhibitor of ethylene synthesis (AOA) reversed the stimulatory effect of NO donors on embryo germination. Additionally SNP
reduced embryo sensitivity to exogenously applied ABA ensuing dormancy breakage. We can conclude that NO acts as a regulatory
factor included in the control of apple embryonic dormancy breakage by stimulation of ethylene biosynthesis. 相似文献
124.
Jolanta M. Siller-Matula Irene M. Lang Thomas Neunteufl Marek Kozinski Gerald Maurer Katarzyna Linkowska Tomasz Grzybowski Jacek Kubica Bernd Jilma 《PloS one》2014,9(7)
Several clinical and genetic variables are associated with influencing high on treatment platelet reactivity (HTPR). The aim of the study was to propose a path model explaining a concurrent impact among variables influencing HTPR and ischemic events. In this prospective cohort study polymorphisms of CYP2C19*2, CYP2C19*17, ABCB1, PON1 alleles and platelet function assessed by Multiple Electrode Aggregometry were assessed in 416 patients undergoing percutaneous coronary intervention treated with clopidogrel and aspirin. The rates of major adverse cardiac events (MACE) were recorded during a 12-month follow up. The path model was calculated by a structural equation modelling. Paths from two clinical characteristics (diabetes mellitus and acute coronary syndrome (ACS)) and two genetic variants (CYP2C19*2 and CYP2C19*17) independently predicted HTPR (path coefficients: 0.11 0.10, 0.17, and -0.10, respectively; p<0.05 for all). By use of those four variables a novel score for prediction of HTPR was built: in a factor-weighted model the risk for HTPR was calculated with an OR of 3.8 (95%CI: 3.1–6.8, p<0.001) for a score level of ≥1 compared with a score of <1. While MACE was independently predicted by HTPR and age in the multivariate model (path coefficient: 0.14 and 0.13, respectively; p<0.05), the coexistence of HTPR and age ≥75 years emerged as the strongest predictor of MACE. Our study suggests a pathway, which might explain indirect and direct impact of variables on clinical outcome: ACS, diabetes mellitus, CYP2C19*2 and CYP2C19*17 genetic variants independently predicted HTPR. In turn, age ≥75 years and HTPR were the strongest predictors of MACE. 相似文献
125.
Gra?yna Lutoslawska Marzena Malara Pawe? Tomaszewski Krzysztof Mazurek Anna Czajkowska Anna K?ska Joanna Tkaczyk 《Journal of physiological anthropology》2014,33(1):10
Background
Limited data have indicated that body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and waist to height ratio (WHtR) of athletes and young adults provide misleading results concerning body fat content. This study was aimed at the evaluation of the relationship between different surrogate indices of fatness (BMI, WC, WHR, WHtR and body adiposity index (BAI)) with the percentage of body fat in Polish students with respect to their sex and physical activity.Methods
A total of 272 students volunteered to participate in the study. Of these students, 177 physical education students (90 males and 87 females) were accepted as active (physical activity of 7 to 9 hours/week); and 95 students of other specializations (49 males and 46 females) were accepted as sedentary (physical activity of 1.5 hours/week). Weight, height, waist and hip circumferences were measured, and BMI, WHR, WHtR and BAI were calculated. Body fat percentage was assessed using four skinfold measurements.Results
Classification of fatness according to the BMI and the percentage of body fat have indicated that BMI overestimates fatness in lean subjects (active men and women, sedentary men), but underestimates body fat in obese subjects (sedentary women). In all groups, BMI, WHR, WHtR and BAI were significantly correlated with the percentage of body fat (with the exception of WHR and hip circumference in active and sedentary women, respectively). However, coefficients of determination not exceeding 50% and Lin’s concordance correlation coefficients lower than 0.9 indicated no relationship between measured and calculated body fat.Conclusion
The findings in the present study support the concept that irrespective of physical activity and sex none of the calculated indices of fatness are useful in the determination of body fat in young adults. Thus, it seems that easily calculated indices may contribute to distorted body image and unhealthy dietary habits observed in many young adults in Western countries, but also in female athletes. 相似文献126.
Hepatitis C virus persistence after spontaneous or treatment-induced resolution of hepatitis C 总被引:14,自引:0,他引:14 下载免费PDF全文
Pham TN MacParland SA Mulrooney PM Cooksley H Naoumov NV Michalak TI 《Journal of virology》2004,78(11):5867-5874
127.
Alex A. Pollen Aparna Bhaduri Madeline G. Andrews Tomasz J. Nowakowski Olivia S. Meyerson Mohammed A. Mostajo-Radji Elizabeth Di Lullo Beatriz Alvarado Melanie Bedolli Max L. Dougherty Ian T. Fiddes Zev N. Kronenberg Joe Shuga Anne A. Leyrat Jay A. West Marina Bershteyn Craig B. Lowe Bryan J. Pavlovic Arnold R. Kriegstein 《Cell》2019,176(4):743-756.e17
128.
129.
Przemyslaw Glaza Jerzy Osipiuk Tomasz Wenta Dorota Zurawa-Janicka Miroslaw Jarzab Adam Lesner Bogdan Banecki Joanna Skorko-Glonek Andrzej Joachimiak Barbara Lipinska 《PloS one》2015,10(6)
Human HtrA3 protease, which induces mitochondria-mediated apoptosis, can be a tumor suppressor and a potential therapeutic target in the treatment of cancer. However, there is little information about its structure and biochemical properties. HtrA3 is composed of an N-terminal domain not required for proteolytic activity, a central serine protease domain and a C-terminal PDZ domain. HtrA3S, its short natural isoform, lacks the PDZ domain which is substituted by a stretch of 7 C-terminal amino acid residues, unique for this isoform. This paper presents the crystal structure of the HtrA3 protease domain together with the PDZ domain (ΔN-HtrA3), showing that the protein forms a trimer whose protease domains are similar to those of human HtrA1 and HtrA2. The ΔN-HtrA3 PDZ domains are placed in a position intermediate between that in the flat saucer-like HtrA1 SAXS structure and the compact pyramidal HtrA2 X-ray structure. The PDZ domain interacts closely with the LB loop of the protease domain in a way not found in other human HtrAs. ΔN-HtrA3 with the PDZ removed (ΔN-HtrA3-ΔPDZ) and an N-terminally truncated HtrA3S (ΔN-HtrA3S) were fully active at a wide range of temperatures and their substrate affinity was not impaired. This indicates that the PDZ domain is dispensable for HtrA3 activity. As determined by size exclusion chromatography, ΔN-HtrA3 formed stable trimers while both ΔN-HtrA3-ΔPDZ and ΔN-HtrA3S were monomeric. This suggests that the presence of the PDZ domain, unlike in HtrA1 and HtrA2, influences HtrA3 trimer formation. The unique C-terminal sequence of ΔN-HtrA3S appeared to have little effect on activity and oligomerization. Additionally, we examined the cleavage specificity of ΔN-HtrA3. Results reported in this paper provide new insights into the structure and function of ΔN-HtrA3, which seems to have a unique combination of features among human HtrA proteases. 相似文献
130.
Duchniewicz M Zemojtel T Kolanczyk M Grossmann S Scheele JS Zwartkruis FJ 《Molecular and cellular biology》2006,26(2):643-653
Studies in tissue culture cells have demonstrated a role for the Ras-like GTPase Rap1 in the regulation of integrin-mediated cell-matrix and cadherin-mediated cell-cell contacts. To analyze the function of Rap1 in vivo, we have disrupted the Rap1A gene by homologous recombination. Mice homozygous for the deletion allele are viable and fertile. However, primary hematopoietic cells isolated from spleen or thymus have a diminished adhesive capacity on ICAM and fibronectin substrates. In addition, polarization of T cells from Rap1-/- cells after CD3 stimulation was impaired compared to that of wild-type cells. Despite this, these defects did not result in hematopoietic or cell homing abnormalities. Although it is possible that the relatively mild phenotype is a consequence of functional complementation by the Rap1B gene, our genetic studies confirm a role for Rap1A in the regulation of integrins. 相似文献