Regular Production of Transgenic Wheat Mediated by Agrobacterium tumefaciens   总被引：4，自引：1，他引：4  

YE Xing-guo  Shirley Sato  XU Hui-jun  DU Li-Pu  Tom Clemente 《中国农业科学(英文版)》2002,1(3):239-244

Wheat is the number one crop both in acreage and total yield in the world. Therefore, it is very important to improve wheat by gene engineering techniques even though it belongs to the plants insensitive to gene transformation, especially to Agrobacterium-mediated transformation. Wheat immature embryos of 1.0-1.5mm in size, C58c1 of Agrobacterium strain harboring pPTN249, pPTN270, pPTN254, and pSIS-GFP respectively (all the vectors contain the aphA selectable gene driven by enhanced 35S promoter and a target gene controlled by ubi promoter or E35S promoter), AB medium for Agrobacterium activate culture, WCC medium for co-culture, were used in this study. The embryos with 4 days of pre-culture were transferred onto selection medium with 10mg/L geneticin, 50mg/L ticarcillin, 50mg/L vancomycin, and 50mg/L cefotaxine after 30 minutes of infection and 2 days of co-cultivation with Agrobacterium. Followed callus production,shoot regeneration on selection medium, 114 resistant plantlets were obtained from 10 transformation experiments of four genotypes. By nptⅡ ELISA (nptⅡ enzyme assay), PCR, Southern blot and leaf bleach,29 positive plants were identified from two genotypes of Bobwhite and Yanglmai 10, with an average transformation efficiency of 0.82 %. The result tested by Southern blot also showed that the transgenic plants with single- copy integration of target gene took 65.52% among total positive plants. The ELISA value of transgenic plant was also related to the copies of alien DNA integrating into wheat chromosomes, the transgenic plants with single copy integration giving higher ELISA value than the ones with 2 or 3 copies integration.  相似文献   

Discovery of a Jupiter/Saturn analog with gravitational microlensing     

Gaudi BS  Bennett DP  Udalski A  Gould A  Christie GW  Maoz D  Dong S  McCormick J  Szymanski MK  Tristram PJ  Nikolaev S  Paczynski B  Kubiak M  Pietrzynski G  Soszynski I  Szewczyk O  Ulaczyk K  Wyrzykowski L;OGLE Collaboration  Depoy DL  Han C  Kaspi S  Lee CU  Mallia F  Natusch T  Pogge RW  Park BG;MuFUN Collaboration  Abe F  Bond IA  Botzler CS  Fukui A  Hearnshaw JB  Itow Y  Kamiya K  Korpela AV  Kilmartin PM  Lin W  Masuda K  Matsubara Y  Motomura M  Muraki Y  Nakamura S  Okumura T  Ohnishi K  Rattenbury NJ  Sako T  Saito T  Sato S 《Science (New York, N.Y.)》2008,319(5865):927-930

Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.  相似文献   

Magnetoencephalography and epilepsy research   总被引：6，自引：0，他引：6  

D F Rose  P D Smith  S Sato 《Science (New York, N.Y.)》1987,238(4825):329-335

Magnetoencephalography is the detection of the magnetic field distribution across the surface of the head, which is generated by a neuronal discharge within the brain. Magnetoencephalography is used in clinical epilepsy to localize the epileptogenic region prior to its surgical removal. A discussion of the instrumentation based on the superconducting quantum interference device that is used for detecting the magnetic field distribution, the analytical techniques, current research, and future directions of magnetoencephalography in epilepsy research is presented.  相似文献   

Molecular Growth Requirements of Single Mammalian Cells     

Sato G  Fisher HW  Puck TT 《Science (New York, N.Y.)》1957,126(3280):461-464

The molecular nutritional requirements exhibited by mammalian cells can vary with the following conditions: whether the cells are plated singly or in massive inoculum; whether a clonal strain or a mixture of different genotypes is employed; whether the macromolecular fraction of serum used as a supplement was previously exposed to prolonged dialysis or other procedures which may release bound micromolecules. In addition, the nature of the medium in which the cells were previously grown, the time permitted for incubation of the cells in the test medium, and the presence of substances or conditions which may specifically introduce the need for certain molecules to preserve balance can strongly influence nutritional requirements. This great versatility may reflect the ability of the mammalian cell to assume different metabolic states characteristic of specific types of differentiation. Under certain conditions, growth of single HeLa cells of the S3 clonal strain requires the presence of cholesterol at a level of 0.5 to 1 microgram per milliliter.  相似文献   

Cross talk between interferon-gamma and -alpha/beta signaling components in caveolar membrane domains     

Takaoka A  Mitani Y  Suemori H  Sato M  Yokochi T  Noguchi S  Tanaka N  Taniguchi T 《Science (New York, N.Y.)》2000,288(5475):2357-2360

  相似文献   

Regulation of mammalian tooth cusp patterning by ectodin     

Kassai Y  Munne P  Hotta Y  Penttilä E  Kavanagh K  Ohbayashi N  Takada S  Thesleff I  Jernvall J  Itoh N 《Science (New York, N.Y.)》2005,309(5743):2067-2070

Mammalian tooth crowns have precise functional requirements but cannot be substantially remodeled after eruption. In developing teeth, epithelial signaling centers, the enamel knots, form at future cusp positions and are the first signs of cusp patterns that distinguish species. We report that ectodin, a secreted bone morphogenetic protein (BMP) inhibitor, is expressed as a "negative" image of mouse enamel knots. Furthermore, we show that ectodin-deficient mice have enlarged enamel knots, highly altered cusp patterns, and extra teeth. Unlike in normal teeth, excess BMP accelerates patterning in ectodin-deficient teeth. We propose that ectodin is critical for robust spatial delineation of enamel knots and cusps.  相似文献   

A gain-of-function mutation in a cytokinin receptor triggers spontaneous root nodule organogenesis     

Tirichine L  Sandal N  Madsen LH  Radutoiu S  Albrektsen AS  Sato S  Asamizu E  Tabata S  Stougaard J 《Science (New York, N.Y.)》2007,315(5808):104-107

Legume root nodules originate from differentiated cortical cells that reenter the cell cycle and form organ primordia. We show that perception of the phytohormone cytokinin is a key element in this switch. Mutation of a Lotus japonicus cytokinin receptor gene leads to spontaneous development of root nodules in the absence of rhizobia or rhizobial signal molecules. The mutant histidine kinase receptor has cytokinin-independent activity and activates an Escherichia coli two-component phosphorelay system in vivo. Mutant analysis shows that cytokinin signaling is required for cell divisions that initiate nodule development and defines an autoregulated process where cytokinin induction of nodule stem cells is controlled by shoots.  相似文献   

A rubberlike stretchable active matrix using elastic conductors     

Sekitani T  Noguchi Y  Hata K  Fukushima T  Aida T  Someya T 《Science (New York, N.Y.)》2008,321(5895):1468-1472

By using an ionic liquid of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, we uniformly dispersed single-walled carbon nanotubes (SWNTs) as chemically stable dopants in a vinylidene fluoride-hexafluoropropylene copolymer matrix to form a composite film. We found that the SWNT content can be increased up to 20 weight percent without reducing the mechanical flexibility or softness of the copolymer. The SWNT composite film was coated with dimethyl-siloxane-based rubber, which exhibited a conductivity of 57 siemens per centimeter and a stretchability of 134%. Further, the elastic conductor was integrated with printed organic transistors to fabricate a rubberlike active matrix with an effective area of 20 by 20 square centimeters. The active matrix sheet can be uniaxially and biaxially stretched by 70% without mechanical or electrical damage. The elastic conductor allows for the construction of electronic integrated circuits, which can be mounted anywhere, including arbitrary curved surfaces and movable parts, such as the joints of a robot's arm.  相似文献   

Adrenergic excitation of cutaneous pain receptors induced by peripheral nerve injury   总被引：25，自引：0，他引：25  

J Sato  E R Perl 《Science (New York, N.Y.)》1991,251(5001):1608-1610

The mechanisms by which peripheral nerve injuries sometimes lead to causalgia, aberrant burning pain peripheral to the site of nerve damage, are uncertain, although the sympathetic nervous system is known to be involved. Whether such syndromes could be the result of the development of responsiveness by some cutaneous pain receptors (C-fiber nociceptors) to sympathetic efferent activity as a consequence of the nerve injury was tested in an animal model. After nerve damage but not in its absence, sympathetic stimulation and norepinephrine were excitatory for a subset of skin C-fiber nociceptors and enhanced the responsiveness of these nociceptors to tissue-damaging stimulation. These effects were demonstratable within days after nerve lesions, occurred at the cutaneous receptive terminal region, were manifest in sensory fibers that had not degenerated after the injury, and were mediated by alpha 2-adrenergic-like receptors.  相似文献   

Robust RNAi-based resistance to mixed infection of three viruses in soybean plants expressing separate short hairpins from a single transgene     

Zhang X  Sato S  Ye X  Dorrance AE  Morris TJ  Clemente TE  Qu F 《Phytopathology》2011,101(11):1264-1269

Transgenic plants expressing double-stranded RNA (dsRNA) of virus origin have been previously shown to confer resistance to virus infections through the highly conserved RNA-targeting process termed RNA silencing or RNA interference (RNAi). In this study we applied this strategy to soybean plants and achieved robust resistance to multiple viruses with a single dsRNA-expressing transgene. Unlike previous reports that relied on the expression of one long inverted repeat (IR) combining sequences of several viruses, our improved strategy utilized a transgene designed to express several shorter IRs. Each of these short IRs contains highly conserved sequences of one virus, forming dsRNA of less than 150 bp. These short dsRNA stems were interspersed with single-stranded sequences to prevent homologous recombination during the transgene assembly process. Three such short IRs with sequences of unrelated soybean-infecting viruses (Alfalfa mosaic virus, Bean pod mottle virus, and Soybean mosaic virus) were assembled into a single transgene under control of the 35S promoter and terminator of Cauliflower mosaic virus. Three independent transgenic lines were obtained and all of them exhibited strong systemic resistance to the simultaneous infection of the three viruses. These results demonstrate the effectiveness of this very straight forward strategy for engineering RNAi-based virus resistance in a major crop plant. More importantly, our strategy of construct assembly makes it easy to incorporate additional short IRs in the transgene, thus expanding the spectrum of virus resistance. Finally, this strategy could be easily adapted to control virus problems of other crop plants.  相似文献