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231.
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Summary The ultrastructure ofOryza sativa L. cells in suspension was determined as cells developed, matured and senesced at 3, 10, and 17 days, respectively, after transfer to fresh medium. Although cultures of 3-day-old cells contained some senescent cells, the symptoms of cell aging were very conspicuous at 10 days and were most pronounced at 17 days. The amount of cytoplasm decreased as the number of lytic areas, myelin figures and vesicle bodies increased. Other noticeable subcellular changes observed were ultrastructural modifications of mitochondria, proplastids, amyloplasts, and nuclei. Such changes were associated with a general deterioration of the lipoprotein complex of the cell during its growth. A fibrous structure without an external membrane was observed and its reported for the first time for cells grown in suspension culture.Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable. 相似文献
233.
M. Tyrka S. Oleszczuk J. Rabiza-Swider H. Wos M. Wedzony J. Zimny A. Ponitka A. Ślusarkiewicz-Jarzina R. J. Metzger P. S. Baenziger A. J. Lukaszewski 《Molecular breeding : new strategies in plant improvement》2018,38(4):46
To create a framework for genetic dissection of hexaploid triticale, six populations of doubled haploid (DH) lines were developed from pairwise hybrids of high-yielding winter triticale cultivars. The six populations comprise between 97 and 231 genotyped DH lines each, totaling 957 DH lines. A consensus genetic map spans 4593.9 cM is composed of 1576 unique DArT markers. The maps reveal several structural rearrangements in triticale genomes. In preliminary tests of the populations and maps, markers specific to wheat segments of the engineered rye chromosome 1R (RM1B) were identified. Example QTL mapping of days to heading in cv. Krakowiak revealed loci on chromosomes 2BL and 2R responsible for extended vernalization requirement, and candidate genes were identified. The material is available to all parties interested in triticale genetics. 相似文献
234.
Jacek Piosik Kacper Wasielewski Anna Woziwodzka Wojciech Śledź Anna Gwizdek-Wiśniewska 《Central European Journal of Biology》2010,5(1):59-66
Caffeine (CAF) is capable of interacting directly with several genotoxic aromatic ligands by stacking aggregation. Formation
of such hetero-complexes may diminish pharmacological activity of these ligands, which is often related to its direct interaction
with DNA. To check these interactions we performed three independent series of spectroscopic titrations for each ligand (ethidium
bromide, EB, and propidium iodine, PI) according to the following setup: DNA with ligand, ligand with CAF and DNA-ligand mixture
with CAF. We analyzed DNA-ligand and ligand-CAF mixtures numerically using well known models: McGhee-von Hippel model for
ligand-DNA interactions and thermodynamic-statistical model of mixed association of caffeine with aromatic ligands developed
by Zdunek et al. (2000). Based on these models we calculated association constants and concentrations of mixture components using a novel
method developed here. Results are in good agreement with parameters calculated in separate experiments and demonstrate de-intercalation
of EB and PI molecules from DNA caused by CAF. 相似文献
235.
Marta Śpibida Beata Krawczyk Marcin Olszewski Józef Kur 《Journal of applied genetics》2017,58(1):133-142
PCR has become an essential tool in biological science. However, researchers often encounter problems with difficult targets, inhibitors accompanying the samples, or PCR trouble related to DNA polymerase. Therefore, PCR optimization is necessary to obtain better results. One solution is using modified DNA polymerases with desirable properties for the experiments. In this article, PCR troubleshooting, depending on the DNA polymerase used, is shown. In addition, the reasons that might justify the need for modification of DNA polymerases, type of modifications, and links between modified DNA polymerases and PCR efficiency are described. 相似文献
236.
Allergy to ragweed: clinical relevance in Turin 总被引:2,自引:0,他引:2
This study evaluates the contribution of ragweed tothe development of allergic manifestations in a groupof outpatients and the atmospheric pollenconcentration trend in the city of Turin (Italy) fromJanuary 1996 to December 1997.We examined 5680 subjects affected byrhinoconjunctivitis and/or bronchial asthma duringspring and summer or by perennial respiratory symptomswith seasonal increase. All subjects were submittedto: (a) a clinical questionnaire; (b) skin prick testswith standard inhalant allergens battery includingpollens of Gramineae, Compositae (Artemisia andAmbrosia), Parietaria, Plantago,Olea, Betula, house dust mite, cat and dogdanders, mould spore (Alternaria and Cladosporium); (c) measurement of specific IgEantibodies in serum (RAST). A weekly programmed Hirstspore-trap was used to sample airborne pollengrains. Pollen was identified and quantified at thePlant Biology Institute of Turin University.The highest concentration of ragweed pollen was 28.6 P/m3 in 1996 and 9.66 P/m3 in 1997.The number of subjects allergic to Ambrosiapollen alone was 8 (0.14% of the total), while thenumber of those allergic to Artemisia absinthiumwas 22 (0.38% of the total). The subjects allergicto both pollens of the Compositae family was 57(1%).Our results show a low prevalence of sensitization toragweed pollen, which is contrary to what we see inother Italian regions like Lombardy and Veneto. Onecause of low sensitization may be the low percentageof Ambrosia pollen in the atmosphere. 相似文献