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111.
Elif Aylin Ozudogru Ergun Kaya Emrah Kirdok Saliha Issever-Ozturk 《In vitro cellular & developmental biology. Plant》2011,47(2):309-320
An efficient in vitro propagation protocol, applicable both to young and mature explants of two Thymus spp., results in genetically stable plantlets. In vitro-grown shoot tips of Thymus vulgaris L. were exposed to cytokinins (6-benzyladenine, kinetin, and thidiazuron) alone or in combination with auxins, gibberellic
acid (GA3) and/or silver nitrate in order to optimize in vitro shoot proliferation. Optimum shoot proliferation (97% regeneration rate, with 8.6 shoots produced per explant) was obtained
when semi-solid Murashige and Skoog (MS) medium was supplemented with 1 mg L−1 kinetin and 0.3 mg L−1 GA3. Rooting of the shoots was easily obtained on semi-solid MS medium that was either hormone-free or supplemented with auxins.
However, the best root apparatus (92.5% rooting rate, with 19 adventitious roots per shoot) developed on MS medium supplemented
with 0.05 mg L−1 2,4-dichlorophenoxyacetic acid. Genetic stability was confirmed in the in vitro-germinated mother plant as well as the shoots that underwent two, four, six, eight, or ten cycles of in vitro subculturing by random amplified polymorphic DNA (RAPD) analysis. When applied to the micropropagation of mature shoot tips
of T. longicaulis C. Presl subsp. longicaulis var. subisophyllus (Borbás) Jalas, the optimized in vitro propagation protocol resulted in a 97.5% shoot regeneration rate, with five shoots formed per explant, and 100% rooting.
Rooted plantlets of both species were transferred to 250-mL plastic pots and successfully acclimatized by gradually reducing
the relative humidity. 相似文献
112.
Yilmaz P Kottmann R Field D Knight R Cole JR Amaral-Zettler L Gilbert JA Karsch-Mizrachi I Johnston A Cochrane G Vaughan R Hunter C Park J Morrison N Rocca-Serra P Sterk P Arumugam M Bailey M Baumgartner L Birren BW Blaser MJ Bonazzi V Booth T Bork P Bushman FD Buttigieg PL Chain PS Charlson E Costello EK Huot-Creasy H Dawyndt P DeSantis T Fierer N Fuhrman JA Gallery RE Gevers D Gibbs RA San Gil I Gonzalez A Gordon JI Guralnick R Hankeln W Highlander S Hugenholtz P Jansson J Kau AL Kelley ST 《Nature biotechnology》2011,29(5):415-420
Here we present a standard developed by the Genomic Standards Consortium (GSC) for reporting marker gene sequences--the minimum information about a marker gene sequence (MIMARKS). We also introduce a system for describing the environment from which a biological sample originates. The 'environmental packages' apply to any genome sequence of known origin and can be used in combination with MIMARKS and other GSC checklists. Finally, to establish a unified standard for describing sequence data and to provide a single point of entry for the scientific community to access and learn about GSC checklists, we present the minimum information about any (x) sequence (MIxS). Adoption of MIxS will enhance our ability to analyze natural genetic diversity documented by massive DNA sequencing efforts from myriad ecosystems in our ever-changing biosphere. 相似文献
113.
Increasing free-energy conservation from the conversion of substrate into product is crucial for further development of many biotechnological processes. In theory, replacing the hydrolysis of disaccharides by a phosphorolytic cleavage reaction provides an opportunity to increase the ATP yield on the disaccharide. To test this concept, we first deleted the native maltose metabolism genes in Saccharomyces cerevisiae. The knockout strain showed no maltose-transport activity and a very low residual maltase activity (0.03 μmol mg protein−1 min−1). Expression of a maltose phosphorylase gene from Lactobacillus sanfranciscensis and the MAL11 maltose-transporter gene resulted in relatively slow growth (μaerobic 0.09±0.03 h−1). Co-expression of Lactococcus lactis β-phosphoglucomutase accelerated maltose utilization via this route (μaerobic 0.21±0.01 h−1, μanaerobic 0.10±0.00 h−1). Replacing maltose hydrolysis with phosphorolysis increased the anaerobic biomass yield on maltose in anaerobic maltose-limited chemostat cultures by 26%, thus demonstrating the potential of phosphorolysis to improve the free-energy conservation of disaccharide metabolism in industrial microorganisms. 相似文献
114.
Yilmaz N Vural H Yilmaz M Sutcu R Sirmali R Hicyilmaz H Delibas N 《Journal of receptor and signal transduction research》2011,31(3):214-219
Calorie restriction (CR) has attracted increased interest since CR enhances lifespan and alters age-related decline in hippocampal-dependent cognitive functions. Obesity is associated with poor neurocognitive outcome including impaired hippocampal synaptic plasticity and cognitive abilities such as learning and memory. N-Methyl-D-aspartate receptors (NMDARs) are linked to hippocampal-dependent learning and memory, which may be stabilized by CR. In the present study, we aimed to establish the effects of CR on NMDARs in CA1 region of hippocampus in obese and non-obese rats. In addition, malondialdehyde (MDA) levels were determined as a marker for lipid peroxidation (LPO) in hippocampus. Four groups were constituted as control group (C, n?=?9), obese group (OB, n?=?10), obese calorie-restricted group (OCR, n?=?9), and non-obese calorie-restricted group (NCR, n?=?10). OCR and NCR were fed with a 60% CR diet for 10 weeks. After 10 weeks of CR, the MDA levels significantly decreased in the calorie-restricted groups. Obesity caused significant decreases in NR2A and NR2B subunit expressions in the hippocampus. The hippocampal NR2A and NR2B levels significantly increased in the OCR group compared with the OB group (P?0.05). In contrast, the hippocampal NR2A and NR2B levels significantly decreased in the NCR group compared with the C group (P?0.05). Oxidative stress can be prevented by CR, and these data may provide a molecular and cellular mechanism by which CR may regulate NMDAR-mediated response against obesity-induced changes in the hippocampus. 相似文献
115.
116.
Sogut S Yonden Z Kaya H Oktar S Tutanc M Yilmaz HR Yigit A Ozcelik N Gali E 《Genetics and molecular research : GMR》2011,10(2):828-833
Oxidative stress may be contributory to the pathophysiology of the abnormalities that underlie the clinical course of sickle cell anemia. We looked for a possible genetic association between the functional polymorphism Ala-9Val in the human Mn-SOD gene and sickle cell anemia. One hundred and twenty-seven patients with sickle cell anemia and 127 healthy controls were recruited into the study. Alanine versus valine polymorphism in the signal peptide of the Mn-SOD gene was evaluated using a primer pair to amplify a 107-bp fragment followed by digestion with the restriction enzyme NgoMIV. In the sickle cell anemia patients, the frequency of Val/Val genotype was approximately 1.4-fold lower and that of Ala/Val was 1.3-fold higher compared to the controls. No significant difference in genotype frequencies was found between patients and controls (χ(2) = 4.561, d.f. = 2, P = 0.101). The Val-9 was the most common allele in patient and healthy subjects. No significant difference in allele frequencies was found between patients and controls (χ(2) = 1.496, d.f. = 1, P = 0.221). We conclude that the Mn-SOD gene polymorphism is not associated with sickle cell anemia. 相似文献
117.
The ATR-Chk1 DNA damage checkpoint pathway is a critical regulator of the cellular response to DNA damage and replication stress in human cells. The variety of environmental, chemotherapeutic, and carcinogenic agents that activate this signal transduction pathway do so primarily through the formation of bulky adducts in DNA and subsequent effects on DNA replication fork progression. Because there are many protein-protein and protein-DNA interactions proposed to be involved in activation and/or maintenance of ATR-Chk1 signaling in vivo, we systematically analyzed the association of a number of ATR-Chk1 pathway proteins with relevant checkpoint-inducing DNA structures in vitro. These DNA substrates included single-stranded DNA, branched DNA, and bulky adduct-containing DNA. We found that many checkpoint proteins show a preference for single-stranded, branched, and bulky adduct-containing DNA in comparison to undamaged, double-stranded DNA. We additionally found that the association of checkpoint proteins with bulky DNA damage relative to undamaged DNA was strongly influenced by the ionic strength of the binding reaction. Interestingly, among the checkpoint proteins analyzed the checkpoint mediator proteins Tipin and Claspin showed the greatest differential affinity for checkpoint-inducing DNA structures. We conclude that the association and accumulation of multiple checkpoint proteins with DNA structures indicative of DNA damage and replication stress likely contribute to optimal ATR-Chk1 DNA damage checkpoint responses. 相似文献
118.
119.
K Kaya 《Progress in lipid research》1992,31(1):87-108
120.