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The endogenous small subunit of the ribulose-1,5-bisphosphate carboxylase gene rbcS and the light-harvesting chlorophyll a/b-binding protein gene (LHCP) of pea are expressed in a light-inducible manner and are active mainly in green chloroplast-containing tissue. Chimeric genes under control of the 5'-flanking sequences of the rbcS ss3.6 or LHCP AB80 genes from pea were used to study the factors relating to the issue-specific and lightinducible expression of these nuclear-encoded genes in transgenic tobacco plants. The results show that plastid development plays a crucial role in the activation of expression of these chimeric genes. Particular members of each of the above gene families respond differently to tissue-specific and environmental factors. Furthermore, the light-inducible expression directed by the 5'-flanking sequence of ss3.6 rbcSgene is not exclusively mediated by phytochrome, but probably is controlledin large part by another photoreceptor. 相似文献
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Tumor DNA structure in plant cells transformed by A. tumefaciens 总被引:25,自引:0,他引:25
P Zambryski M Holsters K Kruger A Depicker J Schell M Van Montagu H M Goodman 《Science (New York, N.Y.)》1980,209(4463):1385-1391
Crown gall tumors are induced in plants by infection with the soil bacterium Agrobacterium tumefaciens. Because the tumor induction involves transfer of a portion of the tumor-inducing (Ti) plasmid DNA from the bacterium to the plant cells, this system is of interest for the study of genetic exchange as well as tumor induction. The boundaries of the transferred DNA (T-DNA) have been cloned from transformed plant cells of tobacco. Detailed mapping with restriction enzymes and nucleotide sequence analysis of two independent clones were used to study the molecular structure of the ends of the T-DNA. One clone contains the two ends of the T-DNA joined together; the other contains one end of the T-DNA joined to repetitive plant DNA sequences. These studies provide direct evidence that the T-DNA can be integrated into the plant genome. In addition, the data suggest that in the plant, T-DNA can be tandemly repeated. Sequence analysis of the junction of crown gall clone 1 reveals several direct repeats as well as an inverted repeat; these structures may be involved in the transfer of the DNA from Agrobacterium to plant cells. 相似文献
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Bright Spots, Structure, and Magmatism in Southern Tibet from INDEPTH Seismic Reflection Profiling 总被引:8,自引:0,他引:8
LD Brown W Zhao KD Nelson M Hauck D Alsdorf A Ross M Cogan M Clark X Liu J Che 《Science (New York, N.Y.)》1996,274(5293):1688-1690
INDEPTH seismic reflection profiling shows that the decollement beneath which Indian lithosphere underthrusts the Himalaya extends at least 225 kilometers north of the Himalayan deformation front to a depth of approximately 50 kilometers. Prominent reflections appear at depths of 15 to 18 kilometers near where the decollement reflector apparently terminates. These reflections extend north of the Zangbo suture to the Damxung graben of the Tibet Plateau. Some of these reflections have locally anomalous amplitudes (bright spots) and coincident negative polarities implying that they are produced by fluids in the crust. The presence of geothermal activity and high heat flow in the regions of these reflections and the tectonic setting suggest that the bright spots mark granitic magmas derived by partial melting of the tectonically thickened crust. 相似文献
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Extract Myophosphorylase deficiency (glycogen storage disease Type V) has been diagnosed in Charolais calves in New Zealand. It is manifested as exercise intolerance and recumbency, usually at several weeks of age, due to an inability to mobilise glucose, as glucose phosphate, from glycogen. Affected calves may rise and walk after a rest to again become affected on further exercise. There is rhabdomyolysis and after repeated or severe attacks the calf may remain recumbent and need to be euthanised. The mutant phosphorylase gene has been described. We have established a PCR-RFLP test based on a published method, and have confirmed the diagnosis in affected calves and heterozygous status of sires, dams and other related individuals belonging to an extended family. In addition, several other non-related heterozygotes have been identified in that and another herd. There appears to have been importations of the gene from both England and America. 相似文献
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AC Johnstone KD McSporran JE Kenny IL Anderson GR MacPherson RD Jolly 《New Zealand veterinary journal》2013,61(6):404-408
AIM: To describe a disease of muscle in Charolais calves and confirm the putative diagnosis of inherited myophosphorylase deficiency. METHODS: Variously stained paraffin sections of muscle prepared from affected calves were used to describe the lesions. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) test was developed and applied to affected calves, their sires, dams and other individuals. RESULTS: The lesions were those of rhabdomyolysis of skeletal muscles and sub-sarcolemmal spaces in normal fibres. The PCR-RFLP test confirmed the expected mutation for phosphorylase deficiency of Charolais cattle in two affected calves. In addition, sires, dams and other closely-related individuals of four affected calves tested as heterozygous for the mutation. Other apparently unrelated animals also tested as heterozygous. CONCLUSIONS: The diagnosis of myophosphorylase deficiency was confirmed. The PCR-RFLP test is suitable for use in controlling this recessively-inherited disorder as it can diagnose heterozygous individuals that are otherwise clinically normal. 相似文献
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Visible quantum cutting in LiGdF4:Eu3+ through downconversion 总被引:1,自引:0,他引:1
For mercury-free fluorescent lamps and plasma display panels, alternative luminescent materials are required for the efficient conversion of vacuum ultraviolet radiation to visible light. Quantum cutting involving the emission of two visible photons for each vacuum ultraviolet photon absorbed is demonstrated in Eu3+-doped LiGdF4 with the concept of downconversion. Upon excitation of Gd3+ with a high-energy photon, two visible photons can be emitted by Eu3+ through an efficient two-step energy transfer from Gd3+ to Eu3+, with a quantum efficiency that approaches 200 percent. 相似文献