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Gene Modification (gene + modification)

Distribution by Scientific Domains

Life Sciences	60%

Selected Abstracts

Methods on erg9 gene deletion in Schizosaccharomyces pombe

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009
Bing Cheng
Abstract Gene modification to key enzymes in biosynthesis pathway becomes familiar technology which can increase efficiency of industrial strains. In the current study, we established a desirable deletion approach based on homologous recombination. It was simple and available for spn5 gene deletion. Also, four kinds of erg9 gene deletion cassettes were constructed in similar manner. The lengths of flanking sequences for homologous integration were from 59 bp to more than 1 Kb, and three selective markers (G418, Zeocin and LEU2) were employed in these cassettes. However, ,erg9 mutant was not obtained in this work. The possible reason is that erg9 gene is an essential gene and a single copy in its chromosome. Deficiency of erg9 gene resulted in nonviability to the cells. In addition, LEU2 marker caused unspecific integration and the difficulty of screening mutants is increased during deletion procedures. This work provides important evidence to modify industrial strains by using deletion technologies. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Transgenic mice expressing tamoxifen-inducible Cre for somatic gene modification in renal epithelial cells

GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 5 2006
Irma S. Lantinga-van Leeuwen
Abstract Gene inactivation often leads to an embryonic-lethal phenotype. In focal diseases like renal cell carcinomas and polycystic kidney disease, somatic gene inactivation in subsets of cells is likely to occur at later stages. We generated a transgenic mouse line with an inducible form of Cre recombinase for conditional gene modifications in kidney epithelial cells. To this end a 1.4-kb promoter fragment of the kidney-specific cadherin gene (KspCad) was cloned upstream of a tamoxifen-inducible Cre recombinase (CreERT2) encoding sequence. Expression and activity of Cre was evaluated using reverse transcriptase polymerase chain reaction (RT-PCR) analysis and by crossbreeding to Z/EG reporter mice. One KspCad-CreERT2 line showed kidney-specific Cre expression and mediated recombination upon tamoxifen treatment in Z/EG reporter mice. No reporter gene expression was detected in untreated animals or in extrarenal tissues upon treatment. Within the kidneys, enhanced green fluorescent protein (EGFP) fluorescence was observed in epithelial cells in several nephronic segments. In addition, the system successfully recombined a floxed Pkd1 gene. genesis 44:225,232, 2006. © 2006 Wiley-Liss, Inc. [source]

Temporal control of gene recombination in astrocytes by transgenic expression of the tamoxifen-inducible DNA recombinase variant CreERT2

GLIA, Issue 1 2006
Petra G. Hirrlinger
Abstract Inducible gene modification using the Cre/loxP system provides a valuable tool for the analysis of gene function in the active animal. GFAP-Cre transgenic mice have been developed to achieve gene recombination in astrocytes, the most abundant cells of the central nervous system, with pivotal roles during brain function and pathology. Unfortunately, these mice displayed neuronal recombination as well, since the GFAP promoter is also active in embryonic radial glia, which possess a substantial neurogenic potential. To enable the temporal control of gene deletions in astrocytes only, we generated a transgenic mouse with expression of CreERT2, a fusion protein of the DNA recombinase Cre and a mutated ligand-binding domain of the estrogen receptor, under the control of the human GFAP promoter. In offspring originating from crossbreedings of GFAP-CreERT2-transgenic mice with various Cre-sensitive reporter mice, consecutive intraperitoneal injections of tamoxifen induced genomic recombination selectively in astrocytes of almost all brain regions. In Bergmann glia, which represent the main astroglial cell population of the cerebellum, virtually all cells showed successful gene recombination. When adult mice received cortical stab wound lesions, simultaneously given tamoxifen induced substantial recombination in reactive glia adjacent to the site of injury. These transgenic GFAP-CreERT2 mice will allow the functional analysis of loxP-modified genes in astroglia of the postnatal and adult brain. © 2006 Wiley-Liss, Inc. [source]

Oncolytic virotherapy for cancer treatment: challenges and solutions

THE JOURNAL OF GENE MEDICINE, Issue 11 2005
J. J. Davis
Abstract Advances in gene modification and viral therapy have led to the development of a variety of vectors in several viral families that are capable of replication specifically in tumor cells. Because of the nature of viral delivery, infection, and replication, this technology, oncolytic virotherapy, may prove valuable for treating cancer patients, especially those with inoperable tumors. Current limitations exist, however, for oncolytic virotherapy. They include the body's B and T cell responses, innate inflammatory reactions, host range, safety risks involved in using modified viruses as treatments, and the requirement that most currently available oncolytic viruses require local administration. Another important constraint is that genetically enhanced vectors may or may not adhere to their replication restrictions in long-term applications. Several solutions and strategies already exist, however, to minimize or circumvent many of these limitations, supporting viral oncolytic therapy as a viable option and powerful tool in the fight against cancer. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Angiogenic gene modification of skeletal muscle cells to compensate for ageing-induced decline in bioengineered functional muscle tissue

BJU INTERNATIONAL, Issue 7 2008
Dawn M. Delo
OBJECTIVE To explore the effects of ageing on the viability of bioengineered striated muscle tissue in vivo, and if this viability can be enhanced by concurrent neovascularization, as its utility for the treatment of stress urinary incontinence (SUI) might be reduced if muscle cells are derived from old patients. MATERIALS AND METHODS Myoblasts were obtained and expanded in culture from young (2 weeks), mature (3 months) and old (24 months) mice, and were engineered to express vascular endothelial growth factor (VEGF) to stimulate neovascularization. Myoblasts were injected subcutaneously into male nude mice and after 2 and 4 weeks, the engineered muscle tissues were harvested. RESULTS Bioengineered muscle tissues were formed in all groups, but the engineered muscles formed by myoblasts from old mice were smaller and less contractile. However, the bioengineered muscles expressing VEGF had a greater mass and better contractility in all age groups. CONCLUSION This pilot study showed that there was an age-related decline in the size and function of bioengineered muscle; however, there was an improvement in volume and function when the muscle cells were expressing VEGF. [source]