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81.
Bt rice expressing Cry1Ab does not stimulate an outbreak of its non-target herbivore, Nilaparvata lugens 总被引:1,自引:0,他引:1
Chen Y Tian JC Wang W Fang Q Akhtar ZR Peng YF Cui H Guo YY Song QS Ye GY 《Transgenic research》2012,21(2):279-291
In this study, the non-target effects of Bt rice “KMD2” expressing a Cry1Ab protein on the performance of the brown planthopper (BPH), Nilaparvata lugens, over multiple generations were evaluated under laboratory and field conditions. In the laboratory, BPH was reared to observe
the impact of the Bt rice as compared to its parental non-Bt cultivar Xiushui 11, while the population dynamics and oviposition performance of BPH were investigated in the field. The
survival of BPH nymphs fed Bt and non-Bt rice did not differ significantly. The nymph developmental duration of BPH was significantly delayed by the Bt rice by comparison with the non-Bt rice for the 1st and 2nd but not the 4th generation. Most importantly, the fecundity of BPH on the Bt rice was significantly decreased in every generation when compared with the non-Bt rice. In the field investigations, the population density of BPH nymphs was significantly lower in the Bt rice field. However, the temporal pattern of population dynamics of BPH adults was similar between the Bt and non-Bt rice, presumably due to migratory interference of the adults. In the Bt rice field, the percentage of tillers with eggs and the number of eggs per tiller were also significantly lower from tillering
to mature stage. Additionally, Cry1Ab protein could not be detected in guts from single BPH adults. In general, our results
suggest that the Bt rice “KMD2” could not stimulate an outbreak of BPH. 相似文献
82.
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84.
Celia CarrilloAziz Hichami Pierre Andreoletti Mustapha Cherkaoui-Malki María del Mar CaviaSouleymane Abdoul-Azize Sara R. Alonso-Torre Naim Akhtar Khan 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2012,1821(4):618-626
Though most of the studies have focused on the effects of free fatty acids on T-cell activation, fatty acids incorporated into plasma membrane phospholipids may also affect cell signaling via diacylglycerol (DAG), generally produced by phospholipid hydrolysis. In the present study, we have synthesized a DAG-containing oleic acid and studied its implication in the modulation of calcium signaling in human Jurkat T-cells. 1-palmitoyl-2-oleoyl-sn-glycerol (POG) induced a dose-dependent increase in [Ca2+]i. This effect was due to the presence of oleic acid at the sn-2 position as no differences were observed between POG and 1-stearoly-2-oleoyl-sn-glycerol (SOG). However, the substitution of oleic acid with arachidonic acid at the sn-2 position of the DAG moiety exerted a different response on the increases in [Ca2+]i in these cells. POG-evoked increases in [Ca2+]i were not due to its metabolites. Furthermore, POG-induced increases in [Ca2+]i were due to the opening of TRPC3/TRPC6 channels as silencing of TRPC3 and TRPC6 genes by shRNA abolished calcium entry. Moreover, disruption of lipid rafts with methyl-β-cyclodextrin completely abolished POG-evoked increases in [Ca2+]i. In conclusion, our results demonstrate that oleic acid can influence T-lymphocyte functions, in the conjugated form of DAG, via opening TRPC3/6 channels. 相似文献
85.
Fang Q Huang CH Ye GY Yao HW Cheng JA Akhtar ZR 《Journal of economic entomology》2008,101(4):1415-1420
The susceptibilities of larvae of two rice stem borers, namely, Chilo suppressalis (Walker) (Lepidoptera: Crambidae) and Sesamia inferens (Walker) (Lepidoptera: Nocutidae) to fipronil and its metabolites were investigated, and then the activities of microsomal O-demethylase, and glutathione transferase (GST) in two species were measured. The metabolism of fipronil in both stem borers was determined in vivo and in vitro. The LD50 value of fipronil to S. inferens was 118.5-fold higher than that of C. suppressalis. The bioassay results offipronil metabolites showed that the toxicities of sulfone and sulfide were higher than fipronil for both species, and the differential toxicity between sulfone and fipronil was remarkable. Alternatively, the activities of microsomal O-demethylase and GST of C. suppressalis were 1.35- and 2.06-fold higher than S. inferens, respectively. The in vivo and in vitro studies on metabolism of fipronil showed that all of fipronil, sulfone, and sulfide were detected and the content of sulfone was higher than sulfide in both stem borers. The residue of sulfone in C. suppressalis was significantly higher than that in S. inferens. These results suggest that the higher activity of mixed function oxidases may cause the higher capacity of C. suppressalis to produce fipronil-sulfone, which is more toxic than fipronil leading to the higher susceptibility of this species. 相似文献
86.
Background
In August 2006 a major epidemic of bluetongue virus serotype 8 (BTV8) started off in North-West Europe. In the course of 2007 it became evident that BTV8 had survived the winter in North-West Europe, re-emerged and spread exponentially. Recently, the European Union decided to start vaccination against BTV8. In order to improve the understanding of the epidemiological situation, it was necessary to execute a cross-sectional serological study at the end of the BT vector season. Cattle were the target species for cross-sectional serological studies in Europe at the end of 2006 and 2007. However, there was no information on the BTV8-seroprevalence in sheep and goats. 相似文献87.
Andrea Veit M. Kalim Akhtar Taeko Mizutani Patrik R. Jones 《Microbial biotechnology》2008,1(5):382-394
NAD(P)H:H2 pathways are theoretically predicted to reach equilibrium at very low partial headspace H2 pressure. An evaluation of the directionality of such near‐equilibrium pathways in vivo, using a defined experimental system, is therefore important in order to determine its potential for application. Many anaerobic microorganisms have evolved NAD(P)H:H2 pathways; however, they are either not genetically tractable, and/or contain multiple H2 synthesis/consumption pathways linked with other more thermodynamically favourable substrates, such as pyruvate. We therefore constructed a synthetic ferredoxin‐dependent NAD(P)H:H2 pathway model system in Escherichia coli BL21(DE3) and experimentally evaluated the thermodynamic limitations of nucleotide pyridine‐dependent H2 synthesis under closed batch conditions. NADPH‐dependent H2 accumulation was observed with a maximum partial H2 pressure equivalent to a biochemically effective intracellular NADPH/NADP+ ratio of 13:1. The molar yield of the NADPH:H2 pathway was restricted by thermodynamic limitations as it was strongly dependent on the headspace : liquid ratio of the culture vessels. When the substrate specificity was extended to NADH, only the reverse pathway directionality, H2 consumption, was observed above a partial H2 pressure of 40 Pa. Substitution of NADH with NADPH or other intermediates, as the main electron acceptor/donor of glucose catabolism and precursor of H2, is more likely to be applicable for H2 production. 相似文献
88.
Haruyoshi Yamaza Kou Matsuo Ieyoshi Kobayashi Hiroko Wada Tamotsu Kiyoshima Merina Akhtar Yukiko Ishibashi Takako Sakai Akifumi Akamine Hidetaka Sakai 《Journal of molecular histology》2001,33(8):437-441
The detailed in situ expression pattern of the Set-α gene has been studied. Previously we showed that Set-α is a differentially expressed gene in the embryonic mouse mandible at day 10.5 (E10.5) gestational age. Cells expressing Set-α were widely distributed in both the epithelial and underlying ectomesenchymal cells at E10.5. At E12, they were slightly aggregated in an area where tooth germ of the lower first molar is estimated to be formed. At E13.5, Set-α was strongly expressed in the tooth germ. At the cap stage, Set-α was expressed in the enamel organ and dental papilla. At the bell stage, Set-α was distinctly expressed in the inner enamel epithelial and dental papilla cells facing the inner enamel epithelial layer, which were intended to differentiate into ameloblasts and odontoblasts, respectively. Interestingly, Set-α was also expressed in several embryonic craniofacial tissues derived from the ectoderm. This study is the first report that Set-α is distinctly expressed in the developing tooth germ, and suggests that Set-α plays an important role in both the initiation and the growth of the tooth germ, as well as in the differentiation of ameloblasts and odontoblasts. 相似文献
89.
L N Manganas S Akhtar D E Antonucci C R Campomanes J O Dolly J S Trimmer 《The Journal of biological chemistry》2001,276(52):49427-49434
Episodic ataxia type 1 (EA-1) is a neurological disorder arising from mutations in the Kv1.1 potassium channel alpha-subunit. EA-1 patients exhibit substantial phenotypic variability resulting from at least 14 distinct EA-1 point mutations. We found that EA-1 missense mutations generate mutant Kv1.1 subunits with folding and intracellular trafficking properties indistinguishable from wild-type Kv1.1. However, the single identified EA-1 nonsense mutation exhibits intracellular aggregation and detergent insolubility. This phenotype can be transferred to co-assembled Kv1 alpha- and Kv beta-subunits associated with Kv1.1 in neurons. These results suggest that as in many neurodegenerative disorders, intracellular aggregation of misfolded Kv1.1-containing channels may contribute to the pathophysiology of EA-1. 相似文献
90.
The effects of omission of Ca2+ and Mg2+ from the incubation medium on three aspects of insulin action in isolated fat cells have been investigated. In the (Ca2+ + Mg2+)-free incubation medium incorporation of L-[14C]leucine into fat cell protein was reduced in the absence of insulin. Insulin stimulated L-[14C]-leucine incorporation only in the presence of added CaCl2 or MgCl2. Incubation of the cells in the (Ca2+ + Mg2+)-free medium reduced but did not abolish the ability of adrenaline to stimulate lipolysis or the ability of insulin to inhibit the adrenaline-stimulated lipolysis. Specific binding of 125I-labelled insulin to the fat cells was reduced in the absence of Ca2+ and Mg2+ but was not abolished, even in the presence of EDTA. Ca2+ was routinely the most effective divalent cation in supporting these aspects of insulin action, but similar responses were obtained with Mg2+, Sr2+ and Ba2+.Since insulin still binds to the cells under conditions in which some of the cellular effects of the hormone are abolished, it is suggested that divalent cations may have a role, either direct or indirect, in the processes linking the insulin-insulin receptor complex to certain effector systems in the cells. It is tentatively suggested that this action occurs at the level of the fat cell plasma membrane. 相似文献