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991.
Fluidity and composition of cell membranes during progression of Mycoplasma canadense cultures grown in a serum-free medium was assessed. The fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene at 25 degrees C of intact cells and liposomes in the exponential and stationary phases of growth was compared. A decrease in fluidity and an increase in the ratio of saturated to unsaturated fatty acids was detected in cell membranes on aging. Nevertheless, membrane density remained unaltered although the molar ratio of cholesterol to phospholipids decreased. It is proposed that the increase in lipid order is primarily due to the increase in the ratio of saturated to unsaturated membrane fatty acids, being the diminished molar ratio of cholesterol to phospholipids involved in the reduced unsaturated fatty acid uptake. 相似文献
992.
Iglesias R Ferreras JM Arias FJ Muñoz R Girbés T 《Biotechnology and bioengineering》1991,37(4):389-391
Ethanol and cycloheximide inhibited the function of the ammonium transport system in growing cultures of Saccharomyces cerevisiae var. ellipsoideus measured as methylamine uptake. The effect was reversible with ethanol and irreversible with the antibiotic. The kinetic data are consistent with a reduction of the number of active carrier molecules located in the plasma membrane. In contrast, neither ethanol nor cycloheximide affected the specific rate of fructose uptake. 相似文献
993.
A new method for the syn-dichlorination of alkenes at room temperature has been proposed by Denmark et al. The method uses diselenide (PhSeSePh) as the precatalyst, benzyltriethylammonium chloride (BnEt3NCl) as the source of chlorine, and an N-fluoropyridinium salt as the oxidant to recover the catalyst. This approach has achieved exquisite diastereocontrol on a number of alkene substrates. In this paper, we report the results of DFT calculations we performed to study the mechanism of this reaction. We were able to identify a reasonable reaction path, including the intermediate and transition-state structures. The results also indicate that PhSeCl3, rather than PhSeCl, is the active catalyst. 相似文献
994.
A 55 K SNP array-based genetic map and its utilization in QTL mapping for productive tiller number in common wheat 总被引:2,自引:0,他引:2
Jiajun Liu Wei Luo Nana Qin Puyang Ding Han Zhang Congcong Yang Yang Mu Huaping Tang Yaxi Liu Wei Li Qiantao Jiang Guoyue Chen Yuming Wei Youliang Zheng Chunji Liu Xiujin Lan Jian Ma 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(11):2439-2450
Key message
A high-density genetic map constructed with a wheat 55 K SNP array was highly consistent with the physical map of this species and it facilitated the identification of a novel major QTL for productive tiller number.Abstract
Productive tiller number (PTN) plays a key role in wheat grain yield. In this study, a recombinant inbred line population with 199 lines derived from a cross between ‘20828’ and ‘Chuannong16’ was used to construct a high-density genetic map using wheat 55 K single nucleotide polymorphism (SNP) array. The constructed genetic map contains 12,109 SNP markers spanning 3021.04 cM across the 21 wheat chromosomes. The orders of the genetic and physical positions of these markers are generally in agreement, and they also match well with those based on the 660 K SNP array from which the one used in this study was derived. The ratios of SNPs located in each of the wheat deletion bins were similar among the wheat 9 K, 55 K, 90 K, 660 K and 820 K SNP arrays. Based on the constructed maps, a novel major quantitative trait locus QPtn.sau-4B for PTN was detected across multi-environments in a 0.55 cM interval on 4B and it explained 17.23–45.46% of the phenotypic variance. Twenty common genes in the physical interval between the flanking markers were identified on chromosome 4B of ‘Chinese Spring’ and wild emmer. These results indicate that wheat 55 K SNP array could be an ideal tool in primary mapping of target genes and the identification of QPtn.sau-4B laid a foundation for the following fine mapping and cloning work.995.
The xenoestrogens biphenol‐A and nonylphenol differentially regulate metalloprotease‐mediated shedding of EGFR ligands 下载免费PDF全文
996.
Qiao Yang Xiaoling Zhang Lingzhi Li Ruonan Zhang Lijuan Feng Jun Mu 《Antonie van Leeuwenhoek》2018,111(6):995-1000
During an investigation of the biodiversity of the cultivable bacterial community associated with paralytic shellfish poisoning toxin-producing marine dinoflagellate, Alexandrium minutum a novel algal-associated bacterium, designated strain AT2-AT was isolated. 16S rRNA gene sequence similarity analysis showed that the strain is a member of the genus Ponticoccus, with high sequence similarity to Ponticoccus litoralis DSM 18986T (97.9%) and Ponticoccus lacteus JCM 30379T (96.0%). However, based on the data obtained for the physiological and biochemical characteristics, and low level of DNA–DNA relatedness analysis, the strain could be genotypically and phenotypically differentiated from two type strains of the genus Ponticoccus. Therefore, this algal-associated bacterial strain is concluded to represent a novel species of the genus Ponticoccus, for which the name Ponticoccus alexandrii sp. nov. is proposed. The type strain is AT2-AT (CCTCC AB 2017228 T = KCTC 52626 T ). 相似文献
997.
García-Nieto P. J. García-Gonzalo E. Alonso Fernández J. R. Díaz Muñiz C. 《Journal of mathematical biology》2018,76(4):817-840
Journal of Mathematical Biology - Eutrophication is a water enrichment in nutrients (mainly phosphorus) that generally leads to symptomatic changes and deterioration of water quality and all its... 相似文献
998.
Víctor G. Almendro-Vedia Carolina García Rubén Ahijado-Guzmán Diego de la Fuente-Herreruela Mónica Muñoz-Úbeda Paolo Natale Montserrat H. Viñas Rodrigo Queiroz Albuquerque Andrés Guerrero-Martínez Francisco Monroy M. Pilar Lillo Iván López-Montero 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2824-2834
Background
The fluorescent dye 10-N-nonyl acridine orange (NAO) is widely used as a mitochondrial marker. NAO was reported to have cytotoxic effects in cultured eukaryotic cells when incubated at high concentrations. Although the biochemical response of NAO-induced toxicity has been well identified, the underlying molecular mechanism has not yet been explored in detail.Methods
We use optical techniques, including fluorescence confocal microscopy and lifetime imaging microscopy (FLIM) both in model membranes built up as giant unilamellar vesicles (GUVs) and cultured cells. These experiments are complemented with computational studies to unravel the molecular mechanism that makes NAO cytotoxic.Results
We have obtained direct evidence that NAO promotes strong membrane adhesion of negatively charged vesicles. The attractive forces are derived from van der Waals interactions between anti-parallel H-dimers of NAO molecules from opposing bilayers. Semi-empirical calculations have confirmed the supramolecular scenario by which anti-parallel NAO molecules form a zipper of bonds at the contact region. The membrane remodeling effect of NAO, as well as the formation of H-dimers, was also confirmed in cultured fibroblasts, as shown by the ultrastructure alteration of the mitochondrial cristae.Conclusions
We conclude that membrane adhesion induced by NAO stacking accounts for the supramolecular basis of its cytotoxicity.General significance
Mitochondria are a potential target for cancer and gene therapies. The alteration of the mitochondrial structure by membrane remodeling agents able to form supramolecular assemblies via adhesion properties could be envisaged as a new therapeutic strategy. 相似文献999.
Fang Zheng Zhang Wenli Zhang Tao Guang Cuie Mu Wanmeng 《Applied microbiology and biotechnology》2018,102(17):7283-7292
Applied Microbiology and Biotechnology - Pentoses represent monosaccharides with five carbon atoms. They are organized into two main groups, aldopentoses and ketopentoses. There are eight... 相似文献
1000.