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981.
双价外壳蛋白基因植物表达载体的构建及马铃薯转基因植株的鉴定 总被引:10,自引:0,他引:10
在克隆了马铃薯X病毒(PVX)、马铃薯Y 病毒(PVY)和马铃薯卷叶病毒(PLRV)的外壳蛋白基因的基础上,构建同时包含PVX和PVY 与PVY 和PLRV 两个外壳蛋白基因植物表达框架的表达载体,通过农杆菌(Agrobacterium tumefaciens)介导转化烟草(Nicotianatabacum )和生产上常用的几个马铃薯(Solanum tuberosum )优良品种:“Favorita”、“虎头”、“克4”。经PCR检测证明外源基因已整合到植物的染色体上,得到批量转基因植株。在转PVX+PVY 外壳蛋白基因的烟草上接种PVX (5 μg/m L)、PVY(20 μg/m L)病毒,得到有一定抗性的植株 相似文献
982.
High percentages of micro-calli and micro-derived embryos were produced from isolated asparagus microspores at late uninucleate stage on MS liquid medium supplemented with 1.0 mg l–1 2,4-D and 0.5 mg l–1 BA. Two types of calli, namely compact callus (CC) and loose callus (LC), were found. Plantlets were regenerated via organogenesis, when these calli were transferred onto MS solid medium supplemented with 1.0 mg l–1 BA and 0.2 mg l–1 IBA 6 weeks. Embryos were produced from liquid cultured microspores, or from solid cultured micro-calli. The frequencies of haploid plant production from organogenesis and embryogenesis were compared. Effects of plant growth regulators on callus production, plantlet regeneration, and haploid plant production were tested. The combination of BA 1.0 mg l–1 and IBA 0.2 mg l–1 resulted the highest precentage of haploid plant production (7.7% from CC, 4.3% from LC).Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- IBA
3-indolybutyric acid
- BA
6-binzyladinine
- NAA
naphtalene acetic acid
- MS
Murashige and Skoog 相似文献
983.
984.
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986.
987.
Barnett YA Eger K Eriksson S Folkers G Hansen PE Hofbauer R Komitowsky D Milon A Munch-Petersen B;European Thymidine Kinase Study Group 《Biotechnology advances》1994,12(4):663-668
A precondition for the chemotherapeutic treatment of a variety of virally-induced human diseases and malignant conditions is a highly selective interaction of the drug molecule to be used with it's biological target. To ensure the development of novel, effective drugs, it is essential that the biological target is well characterised with regard to it's structure and activity. Such characterisation relies upon adequate amounts of pure target being available. One of the most important enzymatic importers for antimetabolites is the enzyme thymidine kinase. In this article an in vitro protein expression system is described which facilitates the production of milligram amounts of pure and biologically active thymidine kinase, from a number of important biological sources. Results have shown that the in vitro produced enzyme has the exact biochemical propeties of the in vivo enzyme. Thus the in vitro protein expression system is an ideal vechicle to facilitate an in depth investigation of the enzyme's biological properties. 相似文献
988.
Lev G. Goldfarb Paul Brown Larisa Cervenakova D. Carleton Gajdusek 《Molecular neurobiology》1994,8(2-3):89-97
Genetic study of over 200 cases of Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), fatal familial insomnia (FFI), and kuru have brought a reliable body of evidence that the familial forms of CJD and all known cases of GSS and FFI are linked to germline mutations in the coding region of the PRNP gene on chromosome 20, either point substitutions or expansion of the number of repeat units. No pathogenic mutations have so far been found in sporadic or infectious forms of CJD, although there are features of genetic predisposition in iatrogenic CJD and kuru. In FFI and familial CJD, clinically and pathologically distinct syndromes that are both linked to the 178Asp→Asn substitution, phenotypic expression is dependent on a polymorphism at codon 129. Synthetic peptides homologous to several regions of PrP spontaneously form insoluble amyloid fibrils with unique morphological characteristics and polymerization tendencies. Peptides homologous to mutated regions of PrP exhibit enhanced fibrilogenic properties and, if mixed with the wild-type peptide, produce even more abundant and larger fibrous aggregates. A similar process in vivo may lead to amyloid accumulation and disease, and transmission of “baby fibrils” may induce disease in other hosts. 相似文献
989.
PrP accumulation in the brains of mice infected with scrapie takes several different forms: amyloid plaques, widespread accumulation
in neuropile, and perineuronal deposits. PrP is also sometimes detected within microglia and in or around astrocytes. There
are dramatic and reproducible differences between scrapie strains in the relative prominence of these changes and their distribution
in the brain. Depending on the scrapie strain, PrP pathology is targeted precisely to particular brain areas, often showing
a clear association with identifiable groups of neurons. These results suggest that PrP changes are primarily associated with
neurons, and that different scrapie strains recognize and selectively replicate in different populations of neurons. Immunostaining
at the ultrastructural level demonstrates an association of PrP with neurite plasmalemma, around amyloid plaques, and in areas
of widespread neuropile and perineuronal accumulation. It is probable that PrP is encoded by theSinc gene, which controls the incubation period of scrapie in mice. Studies using the intraocular infection route show that theSinc gene controls the onset rather than the rate of replication, suggesting that PrP may be involved in cell-to-cell spread of
infection. The accumulation of PrP at the surface of neurons is consistent with such a role. 相似文献
990.
Shukuro Araki Shigehiro Yi Tatsufumi Murakami Susumu Watanabe Shinichi Ikegawa Kiyoshi Takahashi Ken-ichi Yamarnura 《Molecular neurobiology》1994,8(1):15-23
To analyze the pathologic processes of amyloid deposition in type I familial amyloidotic polyneuropathy (FAP), mice were made
transgenic by introducing the human mutant transthyretin (TTR) gene(MT-hMet 30). An inbred strain of mouse, C57 BL/6, was
chosen. Transgenic mice were killed using ether anesthesia at 3-mo intervals up to 24 mo after birth. In these transgenic
mice, amyloid deposition started in the gastrointestinal tract, cardiovascular system, and kidneys and extended to various
other organs and tissues with advancing age. The pattern of amyloid deposition was similar to that observed in human autopsy
cases of FAP, except for its absence in the choroid plexus and in the peripheral and autonomic nervous systems.
We extracted the amyloid fibrils from kidneys of these mice with a human mutant TTR gene and analyzed them immunochemically
and electronmicroscopically. Deposited amyloid was shown to be composed of human mutant TTR and mouse serum amyloid P component.
Amyloid fibril from transgenic mice was morphologically and immunohistochemically similar to that of human FAP.
The most striking pathologic feature of the transgenic mice was the absence of amyloid deposition in the peripheral and autonomic
nervous tissues. Thus, other intrinsic factors may be involved in amyloid deposition in the nervous tissues of human FAP. 相似文献