Wyniki wyszukiwania - Biblioteka Nauki

1

Primordial germ cells ( PGCs) as a tool for creating transgenic chickens

100%

Chojnacka-Puchta L. , Kasperczyk K. , Plucienniczak G. , Sawicka D. , Bednarczyk M.

Polish Journal of Veterinary Sciences

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2012

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tom 15

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nr 1

EN

The transgenic chicken has great potential as a bioreactor for the production of valuable pharmaceutical proteins, notably in the oviduct/egg. Whereas conventional transgenic approaches have significant limitations in this species, an alternative approach employing primordial germ cells (PGCs), the progenitor cells to ova and spermatozoa, has now been successfully applied to the insertion of exogenous genes into birds. Recent developments in manipulating avian embryos make it possible to produce germline chimeras derived from transferred PGCs. In this review we describe the migration pathway of chicken PGCs during early development. We then summarize different methods for the isolation of PGCs and the diversity of techniques used to introduce genes into these cells. Finally, we describe an in vitro assay for testing tissue-specific vectors designed to express heterologous proteins in transgenic chickens.

2

The transgenes are expressed with different level in plants

100%

Yin Z. , Malepszy S.

Biotechnologia

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2003

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nr 2

3

Obtainment of transgenic porcine fibroblast cell lines for the purpose of xenotransplantation

84%

Hryhorowicz M. , Nowak A. , Grzeskowiak B. , Zeyland J. , Slomski R. , Lipinski D.

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2015

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tom 96

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nr 1

4

Nonviral transfection of human umbilical cord blood dendritic cells is feasible, but the yield of dentritic cells with transgene expression limits the application of this method in cancer immunotherapy

84%

Markowicz S. , Niedzielska J. , Kruszewski M. , Oldak T. , Gajkowska A. , Machaj E. K. , Skurzak H. , Pojda Z.

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tom 53

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nr 1

EN

Dendritic cells (DC) generated from human umbilical cord blood might replace patients' DC in attempts to elicit tumor-specific immune response in cancer patients. We studied the efficiency of transfection of human cord blood DC with plasmid DNA carrying the enhanced version of green fluorescent protein (EGFP) as a reporter gene, to test if nonviral gene transfer would be a method to load DC with protein antigens for immunotherapy purposes. Cord blood mononuclear cells were cultured in serum-free medium in the presence of granulocyte-monocyte colony stimulating factor (GM-CSF), stem cell factor (SCF) and Flt-3 ligand (FL), to generate DC from their precursors, and thereafter transfected by electroporation. Maturation of DC was induced by stimulation with GM-CSF, SCF, FL and phorbol myristate acetate (PMA). Transfected DC strongly expressed EGFP, but transfection efficiency of DC, defined as HLA-DR+ cells lacking lineage-specific markers, did not exceed 2.5%. Expression of the reporter gene was also demonstrated in the DC generated from transfected, purified CD34+ cord blood cells, by stimulation with GM-CSF, SCF, FL, and tumor necrosis factor α (TNF-α). Transfection of CD34+ cells was very efficient, but proliferation of the transfected cells was much reduced as compared to the untransfected cells. Therefore, the yield of transgene-expressing DC was relatively low. In conclusion, nonviral transfection of cord blood DC proved feasible, but considering the requirements for immunotherapy in cancer patients, transfection of differentiated DC or generation of DC from transfected hematopoietic stem cells provide only a limited number of DC expressing the transgene.

5

Agrobacterium-mediated transformation of Bangladeshi Indica rices

84%

Al-Forkan M. , Power J. B. , Anthony P. , Lowe K. C. , Davey M. R.

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2004

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tom 09

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nr 2

EN

Morphologically normal, fertile transgenic plants were obtained by co-culturing embryogenic calli of the Bangladeshi Indica rice cultivars BR26 and Binni with Agrobacterium tumefaciens strain LBA4404 carrying the super binary vector pTOK233. Acetosyringone (100 μM) in the medium during coculture (25-28°C) and selection on hygromycin B (50 mg 1-1) were essential for efficient transformation. Stable integration and expression of β-glucuronidase, neomycin phosphotransferase and hygromycin phosphotransferase genes in regenerated plants were confirmed by histochemical and fluorometric assays, ELISA and Southern analysis. Two to 3 copies of T-DNA were integrated into regenerated plants; transgene expression did not correlate with gene copy number. Mendelian segregation of transgenes occurred in T1 seed progeny.

6

Expression pattern of the pre-prothaumatin II gene under the control of the CaMV 35S promoter in transgenic cucumber [Cucumis sativus L.] flower buds and fruits

67%

Szwacka M. , Siedlecka E. , Zawirska-Wojtasiak R. , Wisniewski L. , Malepszy S.

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nr 1

9-16

EN

Thaumatin II is an extremely sweet-tasting protein produced by fruits of the West African shrub Thaumatococcus daniellii Benth, so it can be used in biotechnology to improve the tastes of various plant products. This study is concerned with the spatial and temporal aspects of expression of the 35S-pre-prothaumatin II chimeric gene in flower buds and fruits of transgenic cucumber (Cucumis sativus L.) line 225. The activity of the 35S promoter in organs of line 225 was compared with its activity in 2 other transgenic lines. The accumulation of recombinant thaumatin varied spatially in flower bud tissues of transgenic lines. We found that these differences in the spatial accumulation of transgenic protein concerned the ovary of female buds and the perianth of male buds. In contrast to flower parts, recombinant thaumatin was found in nearly all parts of the young fruit from the transgenic plants. The pre-prothaumatln II gene expression was detected at a very early developmental stage in male buds, and its pattern was rather conserved as the buds aged. The expression of the transgene was also detected in vascular tissues of examined organs but was undetectable in pollen grains, in agreement with the generally held view that the CaMV 35S promoter is virtually silent in pollen. Immunocytochemical analyses of sections of control organs revealed endogenous homolog(s) of thaumatin when using polyclonal antisera, but not when using monoclonal antibodies for recombinant thaumatin detection in transgenic cucumber.

7

Transgenic technology as it applies to animal agriculture

67%

Kopchick J. J. , Jura J. , Mukerji P. , Kelder B.

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nr 2

8

Use of HIV as a gene transfer vector

51%

Pluta K. , Kacprzak M. M.

Acta Biochimica Polonica

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2009

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tom 56

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nr 4

531-595

EN

Despite the extensive research efforts over the past 25 years that have focused on HIV, there is still no cure for AIDS. However, tremendous progress in the understanding of the structure and biology of the HIV virus led to the development of safe and potent HIV-based transgene delivery vectors. These genetic vehicles are referred to as lentiviral vectors. They appear to be better suited for particular applications, such as transgene delivery into stem cells, compared to other viral- and non-viral vectors. This is because Lentivirus-based vectors can efficiently infect nondividing and slowly dividing cells. In the present review article, the current state of understanding of HIV-1 is discussed and the main characteristics that had an impact on vector design are outlined. A historical view on the vector concept is presented to facilitate discussion of recent results in vector engineering in a broader context. Subsequently, a state of the art overview concerning vector construction and vector production is given. This review also touches upon the subject of lentiviral vector safety and related topics that can be helpful in addressing this issue are discussed. Finally, examples of Lentivirus-based gene delivery systems and their applications are presented, with emphasis on animal transgenesis and human gene therapy.