A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, w...A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, we constructed a new system that combined tetracycline- inducible elements with TA29 promoter, a tapetum-specific promoter of tobacco. The system was tested in transient GUS assay system by electroporation (gene gun) transformation of tobacco ( Nicotiana tabacum L. cv. Winsconsin 38) anther. In the absence of tetracycline as the inducer, no GUS activity was detected. However, strong GUS expression was observed in tapetum. tissue upon tetracycline induction, and little GUS activity was found outside the tapetum. Our results suggested that gene expression can be restricted to a specific tissue at the given time under the control of this new system, and this system would be a very useful tool for both basic plant biology research and biotechnological applications.展开更多
Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the comple...Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.展开更多
文摘A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, we constructed a new system that combined tetracycline- inducible elements with TA29 promoter, a tapetum-specific promoter of tobacco. The system was tested in transient GUS assay system by electroporation (gene gun) transformation of tobacco ( Nicotiana tabacum L. cv. Winsconsin 38) anther. In the absence of tetracycline as the inducer, no GUS activity was detected. However, strong GUS expression was observed in tapetum. tissue upon tetracycline induction, and little GUS activity was found outside the tapetum. Our results suggested that gene expression can be restricted to a specific tissue at the given time under the control of this new system, and this system would be a very useful tool for both basic plant biology research and biotechnological applications.
文摘Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.
