Fishes, the biggest and most diverse community in vertebrates are good experimental models for studies of cell and developmental biology by many favorable characteristics. Nuclear transplantation in fish has been th...Fishes, the biggest and most diverse community in vertebrates are good experimental models for studies of cell and developmental biology by many favorable characteristics. Nuclear transplantation in fish has been thoroughly studied in China since 1960s. Fish nuclei of embryonic cells from different genera were transplanted into enucleated eggs generating nucleo-cytoplasmic hybrids of adults. Most importantly, nuclei of cultured goldfish kidney cells had been reprogrammed in enucleated eggs to support embryogenesis and ontogenesis of a fertile fish. This was the first case of cloned fish with somatic cells. Based on the technique of microinjection, recombinant MThGH gene has been transferred into fish eggs and the first batch of transgenic fish were Produced in 1984. The behavior of foreign gene was characterized and the onset of the foreign gene replication occurred between the blastula to gastrula stages and random integration mainly occurred at later stages of embryogenesis. This eventually led to the transgenic mosaicism. The MThGH-transferred common carp enhanced growth rate by 2-4 times in the founder juveniles and doubled the body weight in the adults. The transgenic common carp were more efficient in utilizing dietary protein than the controls. An 'all-fish' gene construct CAgcGH has been made by splicing the common carp β-actin gene (CA) promoter onto the grass carp growth hormone gene (goGH) coding sequence. The CAgcGH-transferred Yellow River Carp have also shown significantly fast-growth trait. Combination of techniques of fish cell culture, gene transformation with cultured cells and nuclear transplantation should be able to generate ho- mogeneous strain of valuable transgenic fish to fulfil human requirement in 21st century展开更多
Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand f...Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.展开更多
Salinity stress is one of the most serious factors limiting the distribution and productivity of crops and forest trees. The detrimental effects of salt on plants are a consequence of both a water deficit resulting in...Salinity stress is one of the most serious factors limiting the distribution and productivity of crops and forest trees. The detrimental effects of salt on plants are a consequence of both a water deficit resulting in osmotic stress and the effects of excess sodium ions on critical biochemical process. A novel approach to improve salt tolerance has been established by using the technology of plant genetic transformation and using loblolly pine (Pinus taeda L.) as a model plant. Mature zygotic embryos of loblolly pine were infected with Agrobacterium tumefaciens strain LBA 4404 harbouring the plasmid pBIGM which carrying the mannitol-1-phosphate dehydrogenase (Mt1D) and glucitol-6-phosphate dehydrogenase (GutD). Organogenic transgenic calli and transgenic regenerated plantlets were produced on selection medium containing 15mg/L kanamycin and confirmed by Southern blot analysis of genomic DNA. Salt tolerance assays demonstrated that the salt tolerance of transgenic calli and regenerated plantlets were increased. These results suggested that an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine has been developed and this could be useful for the future studies on engineering breeding of conifers.展开更多
文摘Fishes, the biggest and most diverse community in vertebrates are good experimental models for studies of cell and developmental biology by many favorable characteristics. Nuclear transplantation in fish has been thoroughly studied in China since 1960s. Fish nuclei of embryonic cells from different genera were transplanted into enucleated eggs generating nucleo-cytoplasmic hybrids of adults. Most importantly, nuclei of cultured goldfish kidney cells had been reprogrammed in enucleated eggs to support embryogenesis and ontogenesis of a fertile fish. This was the first case of cloned fish with somatic cells. Based on the technique of microinjection, recombinant MThGH gene has been transferred into fish eggs and the first batch of transgenic fish were Produced in 1984. The behavior of foreign gene was characterized and the onset of the foreign gene replication occurred between the blastula to gastrula stages and random integration mainly occurred at later stages of embryogenesis. This eventually led to the transgenic mosaicism. The MThGH-transferred common carp enhanced growth rate by 2-4 times in the founder juveniles and doubled the body weight in the adults. The transgenic common carp were more efficient in utilizing dietary protein than the controls. An 'all-fish' gene construct CAgcGH has been made by splicing the common carp β-actin gene (CA) promoter onto the grass carp growth hormone gene (goGH) coding sequence. The CAgcGH-transferred Yellow River Carp have also shown significantly fast-growth trait. Combination of techniques of fish cell culture, gene transformation with cultured cells and nuclear transplantation should be able to generate ho- mogeneous strain of valuable transgenic fish to fulfil human requirement in 21st century
文摘Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.
文摘Salinity stress is one of the most serious factors limiting the distribution and productivity of crops and forest trees. The detrimental effects of salt on plants are a consequence of both a water deficit resulting in osmotic stress and the effects of excess sodium ions on critical biochemical process. A novel approach to improve salt tolerance has been established by using the technology of plant genetic transformation and using loblolly pine (Pinus taeda L.) as a model plant. Mature zygotic embryos of loblolly pine were infected with Agrobacterium tumefaciens strain LBA 4404 harbouring the plasmid pBIGM which carrying the mannitol-1-phosphate dehydrogenase (Mt1D) and glucitol-6-phosphate dehydrogenase (GutD). Organogenic transgenic calli and transgenic regenerated plantlets were produced on selection medium containing 15mg/L kanamycin and confirmed by Southern blot analysis of genomic DNA. Salt tolerance assays demonstrated that the salt tolerance of transgenic calli and regenerated plantlets were increased. These results suggested that an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine has been developed and this could be useful for the future studies on engineering breeding of conifers.
