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31.
R. M. Hauptmann G. della-Cioppa A. G. Smith G. M. Kishore J. M. Widholm 《Molecular & general genetics : MGG》1988,211(2):357-363
Summary A Daucus carota cell line selected as resistant to N-(phosphonomethyl)-glycine (glyphosate) was found to have increased levels of 5-enolpyruvylshikimic acid-3-phosphate synthase (EPSPS) activity of 5.5 times over wild-type carrot and an EPSPS protein level increase of 8.7 times as confirmed by Western hybridization analysis. Southern blot hybridization using a petunia EPSPS probe showed increases in the number of copies of EPSPS genes in the glyphosate-resistant line which correlated with the higher levels of the EPSPS enzyme. The mechanism of resistance to glyphosate is therefore due to amplification of the EPSPS gene. To examine the stability of the amplified genes, cloned lines selected as doubly resistant to Dl-5-methyltryptophan (5MT) and azetidine-2-carboxylate (A2C) were fused with the amplified EPSPS glyphosate-resistant cell line. Somatic hybrids expressed resistances to 5MT in a semidominant fashion while A2C and glyphosate resistance was expressed as dominant, or semi-dominant traits, in a line-specific manner. The hybrid lines possessed additive chromosome numbers of the parental lines used and no double minute chromosomes were observed. The glyphosate-resistant parental line and most somatic hybrids retained the amplified levels of EPSPS in the absence of selection pressure over a 3-year period. 相似文献
32.
We report an extended whole-mount in situ hybridization procedure for Drosophila embryos. By using probes labelled with digoxigenin, fluorescein and biotin, respectively, this protocol allows the detection
in three colours of RNAs derived from three different genes. Hybridized probes are detected by consecutive staining with appropriate
alkaline phosphatase conjugates using different chromogenic substrate combinations, and serial removal of the antibody conjugates
by low pH washes.
Received: 7 May 1996/Accepted: 7 July 1996 相似文献
33.
The nucleotide sequence of poliovirus type 3 leon 12 a1b: comparison with poliovirus type 1. 总被引:46,自引:8,他引:38 下载免费PDF全文
G Stanway A J Cann R Hauptmann P Hughes L D Clarke R C Mountford P D Minor G C Schild J W Almond 《Nucleic acids research》1983,11(16):5629-5643
The complete nucleotide sequence of the genome of the Sabin vaccine strain of poliovirus type 3 (P3/Leon 12 a1 b) has been determined from cDNA cloned in E. coli. The genome comprises a 5' non-coding region of 742 nucleotides, a large open reading frame of 6618 nucleotides (89% of the sequence) and a 3' non-coding region of 72 nucleotides. There is 77.4% base-sequence homology and 89.6% predicted amino-acid homology between types 1 and 3. Conservation of all glutamine-glycine and tyrosine-glycine cleavage sites suggests a mechanism of polyprotein processing similar to that established for poliovirus type 1. 相似文献
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35.
In contrast to rabbit blood plasma, in guinea pig and rat blood plasma activation of fibrinolysis by streptokinase is achieved after addition of human plasminogen or human plasma only. A simple experimental procedure for testing application forms of streptokinase in rats is described. Fibrinolysis in vivo is more effective after subsequent administration of human plasma and streptokinase in rats than after administration of a mixture of human plasma and streptokinase (activator). 相似文献
36.
spiel ohne grenzen/pou2 is required during establishment of the zebrafish midbrain-hindbrain boundary organizer. 总被引:3,自引:0,他引:3
37.
S Clémenceau J F Foncin J Y Muller L Halle G Hauptmann J Seger C Salmon 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1986,303(5):149-154
The hypothesis of a linkage between Alzheimer's disease (AD) (presenile dementia) and the complement components C2, C4, Bf linked to the Major Histocompatibility Complex has been investigated in a large family originating from Calabria, in which AD is transmitted as an autosomal dominant monogenic mendelian trait. The analysis of complotypes of 33 members of a pedigree, from which 10 individuals are affected, allowed to demonstrate that there wasn't any linkage between AD and those markers. Furthermore, no complete or partial deficiency in the C2, C4, Bf components has been observed in affected patients. 相似文献
38.
Nickel D Busch M Mayer D Hagemann B Knoll V Stenger S 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(8):4001-4007
Low oxygen tension is a metabolic hallmark of chronic infection. To investigate the influence of hypoxia on macrophage biology, we analyzed the interaction between the intracellular pathogen Mycobacterium tuberculosis and primary human macrophages. Although the metabolic activity of extracellular M. tuberculosis was reduced at oxygen levels between 0.5 and 10%, the bacilli remained viable throughout the 4 d of culture. Phagocytosis of virulent M. tuberculosis and the pathogen-induced release of inflammatory cytokines by macrophages were not affected by oxygen levels as low as 1%. However, we detected the upregulation of an antimicrobial effector pathway mediated by the vitamin D receptor and human β defensin 2. This finding was functionally relevant, because intracellular mycobacterial growth was inhibited by 58 ± 8% at 1% O(2). We conclude that a hypoxic microenvironment, which is characteristic of infected tissue, supports the efficacy of antimicrobial immunity, in part by the upregulation of the antimicrobial peptide human β defensin 2. 相似文献
39.
Mardones L Zúñiga FA Villagrán M Sotomayor K Mendoza P Escobar D González M Ormazabal V Maldonado M Oñate G Angulo C Concha II Reyes AM Cárcamo JG Barra V Vera JC Rivas CI 《Free radical biology & medicine》2012,52(9):1874-1887
Although there is in vivo evidence suggesting a role for glutathione in the metabolism and tissue distribution of vitamin C, no connection with the vitamin C transport systems has been reported. We show here that disruption of glutathione metabolism with buthionine-(S,R)-sulfoximine (BSO) produced a sustained blockade of ascorbic acid transport in rat hepatocytes and rat hepatoma cells. Rat hepatocytes expressed the Na(+)-coupled ascorbic acid transporter-1 (SVCT1), while hepatoma cells expressed the transporters SVCT1 and SVCT2. BSO-treated rat hepatoma cells showed a two order of magnitude decrease in SVCT1 and SVCT2 mRNA levels, undetectable SVCT1 and SVCT2 protein expression, and lacked the capacity to transport ascorbic acid, effects that were fully reversible on glutathione repletion. Interestingly, although SVCT1 mRNA levels remained unchanged in rat hepatocytes made glutathione deficient by in vivo BSO treatment, SVCT1 protein was absent from the plasma membrane and the cells lacked the capacity to transport ascorbic acid. The specificity of the BSO treatment was indicated by the finding that transport of oxidized vitamin C (dehydroascorbic acid) and glucose transporter expression were unaffected by BSO treatment. Moreover, glutathione depletion failed to affect ascorbic acid transport, and SVCT1 and SVCT2 expression in human hepatoma cells. Therefore, our data indicate an essential role for glutathione in controlling vitamin C metabolism in rat hepatocytes and rat hepatoma cells, two cell types capable of synthesizing ascorbic acid, by regulating the expression and subcellular localization of the transporters involved in the acquisition of ascorbic acid from extracellular sources, an effect not observed in human cells incapable of synthesizing ascorbic acid. 相似文献
40.