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Use of multi-gene downregulation to study cell wall degradation during fruit ripeningSimons, Howard January 1998 (has links)
No description available.
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Studies on methods for the genetic manipulation of barley (Hordeum vulgare L.)Nobre, Jose Manso Preto January 1996 (has links)
No description available.
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Studies on the mouse X-linked mutant linedBlair, Helen J. January 2000 (has links)
No description available.
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Development of Transgenic Livestock with Reduced Myostatin Expression Using RNA InterferenceTessanne, Kimberly J. 2009 December 1900 (has links)
RNA interference (RNAi) is a means of regulating gene expression by targeting
mRNA in a sequence-specific manner for degradation or translational inhibition. Short
hairpin RNAs (shRNAs) and short interfering RNAs (siRNAs) have been extensively
employed for manipulating gene expression in a wide range of species. The goal for this
research was to produce transgenic livestock in which myostatin, a negative regulator of
muscle growth, has been targeted for silencing by RNAi. This would demonstrate the
utility of RNAi for reducing gene expression in large animal species. To successfully
target the myostatin gene for reduction, siRNAs were designed to target the both the
bovine and caprine myostatin mRNA sequence. These were then tested for effectiveness
in vitro using both an HEK 293T cell line expressing caprine myostatin as well as adult
bovine muscle cells. The most effective siRNA, GDF8-1026, was cloned into a lentiviral
plasmid and used to transduce bovine fetal fibroblasts for somatic cell nuclear transfer
cloning as well as perivitelline injection of in vitro produced bovine embryos. To date,
seven pregnancies have been established using these two methods.
Concern over the possibility of off-target effects associated with the expression
of shRNAs in vivo prompted investigation into tissue-specific expression. Therefore,
investigation into the use of a muscle-specific promoter to drive transgene expression
was pursued. The bovine myogenin promoter and muscle creatine kinase (MCK)
promoter were cloned into a lentiviral plasmid and evaluated in bovine fetal muscle cells
and mouse C2C12 cells in vitro for their ability to drive GFP expression. Both promoters
demonstrated an increase in GFP intensity at day nine of differentiation when compared
to the nontransduced control.
The retroviral basis of lentiviral plasmids has raised concern over the possible
development of replication competent lentivirus (RCL). Therefore, analysis of tissues
from recipients of lentivirus-treated embryos was performed to detect possible RCL.
Tissues and blood serum were tested for RCL using p24 ELISA as well as qRT-PCR for
the VSV-G gene. To date all tissues tested so far shown no evidence for RCL using these
analyses. Analysis of offspring transgenic for an shRNA targeting myostatin will allow
confirmation of RNAi as a useful tool for manipulating gene expression in large animal
species.
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Molecular characterization of the insertional mouse mutant yellow submarine, Ysb /Lee, Yin-ting. January 2002 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 94-107).
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Identification of novel immunogenic HLA-DR-restricted peptides from tumour-associated antigensRojas, JoseÌ-Manuel January 2003 (has links)
CD4+ T cells playa central role in antitumour immunity; not only do they provide help for the development of CTL recognising tumour antigens but they can also enhance antitumour responses via indirect cytotoxic mechanisms at the tumour site. Since CD4+ T cells recognise the antigen in the form of pep tides presented on MHC class II molecules, attention has been focused in the recent years on the identification of these peptides derived from tumour antigens. Therefore the aim of this study was to identify novel immunogenic peptides derived from tumour antigens where presentation was restricted to human MHC class II HLA-DRI and/or HLADR4 molecules. The adopted strategy consisted in predicting peptides from the tumour antigens p53, gplOO and bcr-abl(b3a2) using computer-assisted algorithms, and immunisation of HLA-DRI transgenic mice with these peptides in order to assess their immunogenicity. Immunogenic peptides in transgenic mice were then tested in human in in vitro T cell sensitisation assays. To determine peptide immunogenicity in mice, a method was optimised using the reported I-Ak-restricted peptides HEL46-61 and HEL1l 9-132. This model was then successfully established in HLA-DRI transgenic mice with the model peptide HA307- 319. Proliferative responses and IFN-y production were observed when the splenocytes of HLA-DRI transgenic mice were re-presented in vitro with the HA307-319 peptide used in immunisation. Dendritic cells (DC) were shown to be better antigen presenting cells (APC) than syngeneic splenocytes in proliferation assays; thus DC were subsequently used as APC in the all experiments. Further characterisation of DC, generated from bone marrow precursors by culture with GM-CSF, demonstrated that day 8 non-adherent cells matured with LPS were optimal for antigen presentation in this experimental setting. Immunisation of HLA-DRI transgenic mice with predicted peptides from p53, gplOO and bcr-abI(b3a2) resulted in HLA-DRlrestricted responses for two novel p53 peptides (p5363-77 and p53108-122) and two bcrabl peptides (bcr-abIGFK11 and bcr-abIATG1 8). Responses were also observed to two novel gp 100 peptides (gp 1 00194-208 and gp 100566-580). This study demonstrated that HLA-DR-restricted responses to novel peptides can be obtained in HLA-DRI transgenic mice. Furthermore, proliferative responses to p5363-77 in a HLA-DRI + donor, to gpl00566-580 in another HLA-DRl+ donor. and to p53108-122 in two HLA- -1- Abstract DR4+ donors demonstrated that these peptides were also immunogenic in human assays. Collectively, these results indicated that peptide immunisation of HLA-DRI transgenic mice could facilitate the identification of novel immunogenic HLA-DRrestricted pep tides from tumour antigens, that allow us to understand further the role of CD4+ in antitumour immunity and improve cancer immunotherapeutic strategies.
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Characterization of two novel bacillus phytases and their foreseeable applications in transgenic plantsTye, Angela Judith., 戴安琪. January 2002 (has links)
published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy
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Studies on the tissue specificity of the glucose-dependent insulinotropic polypeptide promoter by a transgenic mouse model楊重文, Yeung, Chung-man. January 1997 (has links)
published_or_final_version / Zoology / Master / Master of Philosophy
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Molecular characterization of the insertional mouse mutant yellow submarine, Ysb李彥霆, Lee, Yin-ting. January 2002 (has links)
published_or_final_version / Biochemistry / Master / Master of Philosophy
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Transgenic mouse model of human chondrodysplasia蘇志良, So, Chi-leung. January 1997 (has links)
published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy
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