by Wai Ching Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 154-159). / Abstracts in English and Chinese. / Statement --- p.ii / Acknowledgements --- p.iii / Abstract --- p.v / 摘要 --- p.vii / List of Abbreviations --- p.viii / Table of contents --- p.x / List of Tables --- p.xiv / List of Figures --- p.xv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature review --- p.4 / Chapter 2.1 --- Plant lectins --- p.4 / Chapter 2.1.1 --- Introduction --- p.4 / Chapter 2.1.2 --- Definition and subdivision of plant lectins --- p.4 / Chapter 2.2 --- Monocot mannose-binding lectins --- p.6 / Chapter 2.2.1 --- Occurrence and carbohydrate binding specificity --- p.6 / Chapter 2.2.2 --- Molecular structure and amino acid sequence --- p.7 / Chapter 2.2.3 --- "Molecular cloning, biosynthesis and post-translational modification" --- p.10 / Chapter 2.2.4 --- Mannose-binding lectins of Family Liliaceae --- p.11 / Chapter 2.2.4.1 --- Tulipa gesneriana lectins (TGL) --- p.12 / Chapter 2.2.4.2 --- Aloe arborescens lectins (AAL) --- p.13 / Chapter 2.2.4.3 --- Polygonatum multiflorum agglutinin (PMA) and lectin-related protein --- p.14 / Chapter 2.3 --- Polygonatum odoratum lectins (POL) --- p.15 / Chapter 2.3.1 --- Isolation and purification of POL from Yu Chu --- p.15 / Chapter 2.3.2 --- Agglutinating activity and anti-viral activities of POL --- p.17 / Chapter 2.3.3 --- Bacterial expression of POL in Escherichia coli --- p.18 / Chapter 2.4 --- Plant-based production of recombinant proteins --- p.20 / Chapter 2.4.1 --- Advantages of using plants as expression system --- p.20 / Chapter 2.4.2 --- Plant-derived recombinant proteins --- p.22 / Chapter 2.5 --- Expression of heterologous proteins in rice --- p.24 / Chapter 2.5.1 --- The facts of rice --- p.24 / Chapter 2.5.2 --- Rice storage proteins --- p.25 / Chapter 2.5.2 --- Expression of lysine-rich protein (LRP)/glutelin fusion proteinin rice seeds --- p.28 / Chapter 2.5.3 --- Expression of Galanthus nivalis agglutinin in rice --- p.29 / Chapter 2.6 --- Protein trafficking in plants --- p.30 / Chapter 2.6.1 --- Golgi-dependent pathways --- p.30 / Chapter 2.6.2 --- Golgi-independent pathway --- p.32 / Chapter 2.6.3 --- Expression of protein targeting determinants in tobacco plants and suspension cells --- p.33 / Chapter Chapter 3 --- Materials and Methods --- p.35 / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Chemcials --- p.35 / Chapter 3.3 --- Bacterial strains --- p.35 / Chapter 3.4 --- Cloning of POL cDNA --- p.36 / Chapter 3.4.1 --- Plant materials --- p.36 / Chapter 3.4.2 --- RNA extraction --- p.36 / Chapter 3.4.3 --- RT-PCR amplification of POL cDNA --- p.36 / Chapter 3.4.4 --- 5'RACE and 3'RACE --- p.38 / Chapter 3.4.5 --- Sequencing of POL cDNA --- p.39 / Chapter 3.5 --- Analysis of POL protein --- p.40 / Chapter 3.5.1 --- Protein extraction and Tricine-SDS PAGE --- p.40 / Chapter 3.5.2 --- Western blot analysis --- p.41 / Chapter 3.6 --- Chimeric gene construction --- p.42 / Chapter 3.6.1 --- Construction of the Cauliflower mosaic virus (CaMV)35S promoter/POL constructs --- p.44 / Chapter 3.6.2 --- Construction of the glutelin-1 promoter/POL constructs --- p.48 / Chapter 3.6.3 --- Sequence fidelity of chimeric genes --- p.55 / Chapter 3.7 --- Expression of transgenes in rice --- p.55 / Chapter 3.7.1 --- Plant materials --- p.55 / Chapter 3.7.2 --- Agrobacterium transformation --- p.55 / Chapter 3.7.3 --- Callus induction --- p.56 / Chapter 3.7.4 --- Agrobacterium culture and rice transformation --- p.56 / Chapter 3.7.5 --- Selection and regeneration of rice callus --- p.56 / Chapter 3.7.6 --- Isolation of genomic DNA --- p.58 / Chapter 3.7.7 --- Southern blot analysis --- p.58 / Chapter 3.7.8 --- Extraction of leaf total RNA --- p.59 / Chapter 3.7.9 --- Extraction of seed total RNA --- p.59 / Chapter 3.7.10 --- Northern blot analysis --- p.60 / Chapter 3.7.11 --- Protein extraction and Tricine SDS-PAGE --- p.60 / Chapter 3.7.12 --- Western blot analysis --- p.61 / Chapter 3.8 --- Cytopathic effect (CPE) reduction assay --- p.61 / Chapter 3.8.1 --- Protein extraction --- p.61 / Chapter 3.8.2 --- CPE reduction assay --- p.62 / Chapter 3.9 --- Confocal immunofluorescence --- p.63 / Chapter 3.9.1 --- Preparation of sections --- p.63 / Chapter 3.9.2 --- Labelling of fluorescence probes --- p.63 / Chapter 3.9.3 --- Image collection --- p.64 / Chapter Chapter 4 --- Results --- p.65 / Chapter 4.1 --- Cloning of POL cDNA from Yu Chu --- p.65 / Chapter 4.1.1 --- RNA extraction and partial POL cDNA amplification --- p.65 / Chapter 4.1.2 --- 5'RACE and 3'RACE --- p.67 / Chapter 4.1.3 --- Sequencing of POL cDNA --- p.68 / Chapter 4.1.4 --- Sequences comparison of POL and Liliaceae lectins --- p.75 / Chapter 4.2 --- Occurence of POL protein in Yu Chu plant --- p.77 / Chapter 4.3 --- Constitutional expression of POL in rice --- p.79 / Chapter 4.3.1 --- Construction of Cauliflower mosaic virus 35S promoter constructs --- p.80 / Chapter 4.3.2 --- Southern blot analysis --- p.82 / Chapter 4.3.3 --- Northern blot analysis --- p.84 / Chapter 4.3.4 --- Western blot analysis --- p.85 / Chapter 4.3.5 --- Western blot analysis of 35S/POL T1 plant --- p.87 / Chapter 4.4 --- Seed-specific expression of POL in rice --- p.88 / Chapter 4.4.1 --- Construction of the glutelin-1 promoter constructs --- p.89 / Chapter 4.4.2 --- Southern blot analysis --- p.92 / Chapter 4.4.3 --- Northern blot analysis --- p.96 / Chapter 4.4.4 --- Western blot analysis --- p.101 / Chapter 4.4.5 --- Western blot analysis of POL-BP-8O and POL-α-TIP T1 transgenic plants --- p.117 / Chapter 4.5 --- Cytopathic effect (CPE) reduction assay --- p.122 / Chapter 4.6 --- Confocal immunofluorescence studies --- p.125 / Chapter Chapter 5 --- Discussion --- p.134 / Chapter 5.1 --- Cloning of POL cDNA --- p.134 / Chapter 5.2 --- Analysis of constitutional expression of POL in rice --- p.136 / Chapter 5.3 --- Analysis of seed-specific expression of POL in rice --- p.138 / Chapter 5.4 --- Localization of POL in POL-BP-8O and POL-α-TIP transgenic rice seeds --- p.146 / Chapter 5.5 --- Cytopathic effect (CPE) reduction assay --- p.148 / Chapter 5.6 --- Future prospects --- p.151 / Chapter Chapter 6 --- Conclusion --- p.153

Microglial activation and behavioral abnormalities occur before neuronal loss in experimental murine prion disease; the behavioral changes coincide with a reduction in synaptic plasticity. Because synaptic plasticity depends on an intact perineuronal net (PN), a specialized extracellular matrix that surrounds parvalbumin (PV)-positive GABAergic (gamma-aminobutyric acid [GABA]) inhibitory interneurons, we investigated the temporal relationships between microglial activation and loss of PN and PV-positive neurons in ME7 murine prion disease. Anesthetized C57Bl/6J mice received bilateral intracerebral microinjections of ME7-infected or normal brain homogenate into the dorsal hippocampus. Microglial activation, PrP accumulation, the number of PV-positive interneurons, and Wisteria floribunda agglutinin-positive neurons (i.e. those with an intact PN) were assessed in the ventral CA1 and subiculum at 4, 8, 12, 16, and 20 weeks postinjection. Hippocampal areas and total neuron numbers in the ventral CA1 and subiculum were also determined. Loss of PN coincided with early microglial activation and with a reduction in synaptic plasticity. No significant loss of PV-positive interneurons was observed. Our findings suggest that the substrate of the earliest synaptic and behavioral abnormalities in murine prion disease may be inflammatory microglia-mediated degradation of the PN.