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1.
We have isolated the delta-globin gene of the New-World spider monkey,
Ateles geoffroyi, and compared its nucleotide sequence with those of other
primate delta- and beta-globin genes. Among primate delta-globin genes, the
rate of nonsynonymous substitutions is much less than the rate of
synonymous substitutions. This suggests that primate delta- globin genes
may remain under evolutionary conservation, perhaps because hemoglobin A2
has an as yet unknown physiological importance.
相似文献
2.
Biochemical pathways in prokaryotes can be traced backward through evolutionary time 总被引:10,自引:0,他引:10
For the first time, a credible prokaryotic phylogenetic tree is being
assembled by Woese and others using quantitative sequence analysis of
oligonucleotides in the highly conservative rRNA. This provides an
evolutionary scale against which the evolutionary steps that led to the
arrangement and regulation of contemporary biochemical pathways can be
measured. This paper presents an emerging evolutionary picture of aromatic
amino acid biosynthesis within a large superfamily assemblage of
prokaryotes that is sufficiently developed to illustrate a new perspective
that will be applicable to many other biochemical pathways.
相似文献
3.
In Drosophila pseudoobscura, the amylase (Amy) multigene family is
contained within a series of inversions, or gene arrangements, on the third
chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL)
inversions are central to the phylogeny of arrangements, and have clusters
of other arrangements derived from them. The gene arrangements belonging to
each of these three clusters have a characteristic number of Amy genes,
ranging from three in ST to two in SC to one in TL. This distribution
pattern can reflect a history of either duplications or deletions, although
the data available in the past did not permit a decision between these
alternatives. We provide unambiguous evidence that three Amy genes were
present before the divergence of the ST, SC, and TL arrangements. Thus, the
current status of the Amy multigene family is the result of deletions in
the TL and SC arrangements, which created three new pseudogenes: TL
Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences
revealed that, in the SC and ST arrangements, pseudogene evolution has been
retarded, most likely due to the homogenization effect of gene conversion.
Finally, by determining the original copy number, we have reconstructed the
evolutionary history of the Amy multigene family and linked it with the
evolution of the central gene arrangements.
相似文献
4.
The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R2 values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures. 相似文献
5.
6.
Aurélie Hurtevent Morgan Le Naour Veronique Leclerc Pascal Carato Patricia Melnyk Nathalie Hennuyer 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):524-538
Abstract A series of nitrogen heterocycles containing α–ethoxyphenylpropionic acid derivatives were designed as dual PPARα/γ agonist ligands for the treatment of type 2 diabetes (T2D) and its complications. 6-Benzoyl-benzothiazol-2-one was the most tolerant of the tested heterocycles in which incorporation of O-methyl oxime ether and trifluoroethoxy group followed by enantiomeric resolution led to the (S)-stereoisomer 44?b displaying the best in vitro pharmacological profile. Compound 44?b acted as a very potent full PPARγ agonist and a weak partial agonist on the PPARα receptor subtype. Compound 44?b showed high efficacy in an ob/ob mice model with significant decreases in serum triglyceride, glucose and insulin levels but mostly with limited body-weight gain and could be considered as a selective PPARγ modulator (SPPARγM). 相似文献
7.
The K+/H+ antiporter LeNHX2 increases salt tolerance by improving K+ homeostasis in transgenic tomato 总被引:1,自引:0,他引:1
RAÚL HUERTAS LOURDES RUBIO OLIVIER CAGNAC MARÍA JESÚS GARCÍA‐SÁNCHEZ JUAN DE DIOS ALCHÉ KEES VENEMA JOSÉ ANTONIO FERNÁNDEZ MARÍA PILAR RODRÍGUEZ‐ROSALES 《Plant, cell & environment》2013,36(12):2135-2149
The endosomal LeNHX2 ion transporter exchanges H+ with K+ and, to lesser extent, Na+. Here, we investigated the response to NaCl supply and K+ deprivation in transgenic tomato (Solanum lycopersicum L.) overexpressing LeNHX2 and show that transformed tomato plants grew better in saline conditions than untransformed controls, whereas in the absence of K+ the opposite was found. Analysis of mineral composition showed a higher K+ content in roots, shoots and xylem sap of transgenic plants and no differences in Na+ content between transgenic and untransformed plants grown either in the presence or the absence of 120 mm NaCl. Transgenic plants showed higher Na+/H+ and, above all, K+/H+ transport activity in root intracellular membrane vesicles. Under K+ limiting conditions, transgenic plants enhanced root expression of the high‐affinity K+ uptake system HAK5 compared to untransformed controls. Furthermore, tomato overexpressing LeNHX2 showed twofold higher K+ depletion rates and half cytosolic K+ activity than untransformed controls. Under NaCl stress, transgenic plants showed higher uptake velocity for K+ and lower cytosolic K+ activity than untransformed plants. These results indicate the fundamental role of K+ homeostasis in the better performance of LeNHX2 overexpressing tomato under NaCl stress. 相似文献
8.
Andrii K. Melnyk Olexandr V. Sukhoveev Lyudmyla A. Kononets Olexandr M. Khilchevsky Valery P. Kukhar 《Journal of liposome research》2016,26(1):80-86
Comparative properties of lecithin-based liposomes prepared from the mixed phospholipids of sunflower seeds, soybean and egg yolk were investigated by electron paramagnetic resonance (EPR) spectroscopy. For these investigations, stable nitroxide radicals, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 5,7-dimethyladamantane-1-carboxylate (DMAC-TEMPO), 5-doxylstearic acid (5-DSA) and 16-doxylstearic acid (16-DSA) were used as spin probes. Binding of the spin probes to the liposome membranes resulted in a substantial increase of the apparent rotational diffusion correlation times. The EPR spectra of the incorporated nitroxides underwent temperature-dependent changes. For every spin probe, values of apparent enthalpy and entropy of activation were calculated from the temperature dependence of rotational diffusion correlation times via Arrhenius equation. In case of DMAC-TEMPO, the data point to differences between the phospholipid bilayer of liposomes derived from sunflower and soy lecithin, and some similarity between the sunflower and egg yolk liposomes. Anisotropic hyperfine interaction constants of DMAC-TEMPO and 16-DSA included in the liposomes have been analyzed and attributed to different micropolarity of the surroundings of the spin probes. The kinetics of EPR signal decay of DMAC-TEMPO in the presence of 2,2′-azobis(2-amidinopropane) suggest the better stability of the sunflower liposomes to lipid peroxidation as compared to the liposomes prepared from soy lecithin. 相似文献
9.
Homocysteine metabolism in children with Down syndrome: in vitro modulation 总被引:8,自引:0,他引:8 下载免费PDF全文
Pogribna M Melnyk S Pogribny I Chango A Yi P James SJ 《American journal of human genetics》2001,69(1):88-95
The gene for cystathionine beta-synthase (CBS) is located on chromosome 21 and is overexpressed in children with Down syndrome (DS), or trisomy 21. The dual purpose of the present study was to evaluate the impact of overexpression of the CBS gene on homocysteine metabolism in children with DS and to determine whether the supplementation of trisomy 21 lymphoblasts in vitro with selected nutrients would shift the genetically induced metabolic imbalance. Plasma samples were obtained from 42 children with karyotypically confirmed full trisomy 21 and from 36 normal siblings (mean age 7.4 years). Metabolites involved in homocysteine metabolism were measured and compared to those of normal siblings used as controls. Lymphocyte DNA methylation status was determined as a functional endpoint. The results indicated that plasma levels of homocysteine, methionine, S-adenosylhomocysteine, and S-adenosylmethionine were all significantly decreased in children with DS and that their lymphocyte DNA was hypermethylated relative to that in normal siblings. Plasma levels of cystathionine and cysteine were significantly increased, consistent with an increase in CBS activity. Plasma glutathione levels were significantly reduced in the children with DS and may reflect an increase in oxidative stress due to the overexpression of the superoxide dismutase gene, also located on chromosome 21. The addition of methionine, folinic acid, methyl-B(12), thymidine, or dimethylglycine to the cultured trisomy 21 lymphoblastoid cells improved the metabolic profile in vitro. The increased activity of CBS in children with DS significantly alters homocysteine metabolism such that the folate-dependent resynthesis of methionine is compromised. The decreased availability of homocysteine promotes the well-established "folate trap," creating a functional folate deficiency that may contribute to the metabolic pathology of this complex genetic disorder. 相似文献
10.
Olivier C Hot D Huot L Ollivier N El-Mahdi O Gouyette C Huynh-Dinh T Gras-Masse H Lemoine Y Melnyk O 《Bioconjugate chemistry》2003,14(2):430-439
We describe in this paper the preparation and characterization of semicarbazide glass slides and their use for the fabrication of microarrays using site-specific alpha-oxo semicarbazone ligation. The functional density and homogeneity of the semicarbazide glass slides were optimized by analyzing the reactivity of the layer toward a synthetic glyoxylyl fluorescent probe. Oligonucleotide microarrays were prepared by site-specific immobilization of glyoxylyl oligodeoxynucleotides. The slides were directly used in the hybridization assays using fluorescence detection and displayed a significant gain in sensibility as compared to the aldehyde glass slide/amino oligodeoxynucleotide chemistry. Semicarbazide slides were also used for the immobilization of a biotinylated peptide alpha-oxo aldehyde. The peptide microarrays allowed model interaction studies with streptavidin or an anti-biotin antibody. 相似文献