Liu Suk Ching. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 123-128.

by Yu Wai Fu, Jason. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 112-120). / ACKNOWLEDGMENTS --- p.i / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iii / Chapter CHAPTER 1 --- INTORDUCTION --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Historical Overview --- p.3 / Chapter 1.2.1 --- Insulin-Like Growth Factors I and II --- p.3 / Chapter 1.2.2 --- IGF Receptors --- p.5 / Chapter 1.2.3 --- IGF Binding Proteins --- p.7 / Chapter 1.3 --- Origin and Production of IGFs --- p.7 / Chapter 1.3.1 --- The Hypothalamo-Pituitary-GH-IGF-I Axis --- p.7 / Chapter 1.3.2 --- Factors Regulating IGF production --- p.9 / Chapter 1.3.3 --- Expression of IGFs in the Central Nervous System --- p.11 / Chapter 1.4 --- Actions of IGFs --- p.12 / Chapter 1.4.1 --- Insulin-like Metabolic Effects --- p.12 / Chapter 1.4.2 --- Mitogenic Effects --- p.13 / Chapter 1.4.3 --- Effects on Differentiation --- p.13 / Chapter 1.4.4 --- IGFs in Reproductive System --- p.14 / Chapter 1.4.5 --- IGF Actions in the Central Nervous System --- p.14 / Chapter 1.5 --- Transgenic and Knockout Animal Models for IGFs --- p.15 / Chapter 1.6 --- Molecular Biology of IGFs --- p.17 / Chapter 1.6.1 --- Structure of the IGF Genes --- p.17 / Chapter 1.6.2 --- Expression of IGF Genes --- p.21 / Chapter 1.6.3 --- Regulation of IGF Gene Expression --- p.23 / Chapter 1.7 --- IGF Receptors --- p.24 / Chapter 1.7.1 --- IGF-I Receptor --- p.24 / Chapter 1.7.2 --- IGF-II Receptor --- p.26 / Chapter 1.8 --- IGFBPs --- p.26 / Chapter 1.9 --- Teleost IGFs --- p.28 / Chapter 1.9.1 --- The GH-IGF-Axis in Teleost --- p.28 / Chapter 1.9.2 --- Osmoregulation and Other Biological Actions of IGFin Teleost --- p.29 / Chapter 1.9.3 --- Molecular Biology of IGFs in Teleost --- p.30 / Chapter 1.9.4 --- IGFBPs and IGF Receptors in Teleost --- p.31 / Chapter 1.10 --- Rationale and Aim of the Present Study --- p.32 / Chapter CHAPTER 2 --- SEARCH OF IGF-I PROMOTER BY GENOMIC DNA POLYMERASE CHAIN REACTION --- p.34 / Chapter 2.1 --- Introduction --- p.34 / Chapter 2.2 --- Materials --- p.35 / Chapter 2.3 --- Methods --- p.39 / Chapter 2.3.1 --- Preparation of Genomic DNA from Carp Testis --- p.39 / Chapter 2.3.2 --- Restriction Enzyme Digestion of Genomic DNA --- p.40 / Chapter 2.3.3 --- Polymerase Chain Reaction --- p.40 / Chapter 2.3.3.1 --- Ligation of the Cassette to Digested Genomic DNA --- p.40 / Chapter 2.3.3.2 --- Amplification by PCR --- p.40 / Chapter 2.3.4 --- Agarose Gel Electrophoresis --- p.42 / Chapter 2.3.5 --- Gene Clean Using Sephaglas´ёØ BandPrep Kit (Pharamica) --- p.42 / Chapter 2.3.6 --- Cloning of PCR Products --- p.43 / Chapter 2.3.7 --- Transformation of Competent Cell (Heat Shock Method) --- p.43 / Chapter 2.3.8 --- Small Scale Alkaline Preparation of Plasmid DNA --- p.44 / Chapter 2.3.9 --- Restriction Enzyme Digestion to Release the Insert --- p.45 / Chapter 2.3.10 --- Large Scale Plasmid Preparation of the Positive Clone --- p.45 / Chapter 2.3.11 --- DNA Sequencing of the Positive Clone Using the T7 DNA Polymerase Sequencing Kit (Pharmacia) --- p.46 / Chapter 2.4 --- Results and Discussion --- p.49 / Chapter CHAPTER 3 --- ISOLATION OF GENOMIC CLONES CARRYING THE IGF-I GENE --- p.55 / Chapter 3.1 --- Introduction --- p.55 / Chapter 3.2 --- Materials --- p.56 / Chapter 3.3 --- Methods --- p.58 / Chapter 3.3.1 --- Preparation of the Plating Host Cells --- p.58 / Chapter 3.3.2 --- Phage Titering --- p.58 / Chapter 3.3.3 --- Primary Screening of Common Carp Genomic Library --- p.59 / Chapter 3.3.4 --- Preparation of Radioactive Nucleic Acid Probes --- p.60 / Chapter 3.3.5 --- Purification of the Positive Clones --- p.60 / Chapter 3.3.6 --- Purification of DNA from Lambda Phage Using Sephaglas´ёØ PhagePrep Kit (Pharmacia) --- p.61 / Chapter 3.3.7 --- Restriction Enzyme Digestion Release of Inserts --- p.62 / Chapter 3.3.8 --- Capillary Transfer of DNA to Nylon Membrane Under Alkaline Condition --- p.62 / Chapter 3.3.9 --- Southern Analysis of the 10 Positive Clones --- p.63 / Chapter 3.3.10 --- Restriction Mapping of the Clone P1 --- p.64 / Chapter 3.3.11 --- Subcloning of the Fragments of the Clone PI into Plasmid Vector --- p.64 / Chapter 3.3.12 --- IGF-I Specific PCR --- p.64 / Chapter 3.3.13 --- Amplification of Introns from the Clone P1 Using PCR --- p.67 / Chapter 3.4 --- Results and Discussion --- p.70 / Chapter CHAPTER 4 --- RNA ASSAY USING REVERSE TRANSCRIPTION- POLYMERASE CHAIN REACTION --- p.83 / Chapter 4.1 --- Introduction --- p.83 / Chapter 4.2 --- Materials --- p.85 / Chapter 4.3 --- Methods --- p.86 / Chapter 4.3.1 --- Administration of Hormones --- p.86 / Chapter 4.3.1.1 --- Injection Time Course1 --- p.86 / Chapter 4.3.1.2 --- Injection Time Course2 --- p.86 / Chapter 4.3.2 --- Total RNA Extraction --- p.87 / Chapter 4.3.2.1 --- Rapid RNA Isolation --- p.87 / Chapter 4.3.3 --- Electrophoresis of RNA in Agarose Gel Containing Formaldehyde --- p.88 / Chapter 4.3.4 --- Rapid Isolation of PolyA+ mRNA from Total RNA --- p.89 / Chapter 4.3.5 --- IGF-I Specific RT-PCR --- p.90 / Chapter 4.4 --- Results and Discussion --- p.92 / Chapter CHAPTER 5 --- SEARCH FOR IGF-II GENE USING GENOMIC SOUTHERN BLOT ANALYSIS --- p.101 / Chapter 5.1 --- Introduction --- p.101 / Chapter 5.2 --- Materials --- p.103 / Chapter 5.3 --- Methods --- p.104 / Chapter 5.3.1 --- Preparation of Genomic DNA from Carp Testis --- p.104 / Chapter 5.3.2 --- Restriction Enzyme Digestion of Genomic DNA --- p.104 / Chapter 5.3.3 --- Southern Blotting of the Digested Genomic DNA --- p.104 / Chapter 5.3.4 --- Preparation of the Trout IGF-II Specific Probe --- p.104 / Chapter 5.3.5 --- Genomic Southern Hybridization --- p.105 / Chapter 5.4 --- Results and Discussion --- p.106 / Chapter CHAPTER 6 --- GENERAL DISCUSSION AND CONCLUSION --- p.109 / REFERENCES --- p.112

The auxin-resistant diageotropica (dgt) mutant of tomato (Lycopersicon esculentum Mill.) has a pleiotropic phenotype including a lack of lateral roots and reduced gravitropic response, apical dominance, vascular development, and fruit growth. The dgt mutation reduces the auxin sensitivity of only a subset of auxin responses while levels, metabolism, and transport of auxin appear normal, suggesting that the Dgt gene encodes a component in an auxin-signaling pathway. This dissertation reports isolation and characterization of the Dgt gene. Delineation of three microsyntenic regions in the Arabidopsis genome containing genes homeologous to genetic markers near the Dgt gene allowed isolation of additional ESTs from the corresponding tomato region, significantly reducing the mapping distance to the dgt locus. Further analysis determined that the Dgt gene encodes a cyclophilin (LeCYP1), a previously unidentified component of auxin signaling. Each known dgt allele contains a unique mutation in the coding sequence of LeCyp1. In addition, the wild-type Dgt gene can complement dgt mutant plants. Cyclophilins characteristically have peptidylprolyl cis-trans isomerase (PPIase) activity, but it is unclear whether that activity is necessary for all of their biological functions. Each allelic dgt mutation reduces or nullifies PPIase activity of LeCYP1 fusion proteins in vitro. Immunoblot analysis indicates that all three dgt mutations are null mutations. Phylogenetic comparisons of tomato and Arabidopsis cytosolic-type cyclophilins could not identify any single Arabidopsis member as orthologous to LeCYP1/DGT. Five T-DNA insertion mutants were analyzed to determine if mutations in Arabidopsis cytosolic-type cyclophilins phenocopy the pleiotropic dgt phenotype. Overall seedling growth and morphology appear normal in the mutants, however, their gravitropic response is slow. The lack of exact phenocopy may be due to the redundant nature of Cyp genes in Arabidopsis, which has over twice as many Cyp genes as tomato. In tomato, the cyclophilin inhibitor cyclosporin A (CsA) inhibits auxin-induced adventitious root initiation and expression of two early auxin response genes, LeIAA10 and 11, that are also affected by the dgt mutation. Taken together, these results suggest that the cyclophilin encoded by the Dgt gene plays an important role in auxin signal transduction. / Graduation date: 2004

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 98-115).

No description available.

This study has succeeded in identifying, cloning and sequencing three genes previously unknown in R. sphaeroides, che W, che R and che Y2. These genes are homologous to genes recently discovered in Rhizobium meliloti and also show a lesser homology to genes in other organisms including the well characterised enteric chemotaxis genes. A comparative analysis of the deduced proteins has been made to determine structural and functional similarities between the R. sphaeroides genes and their homologues in R. meliloti and in E. coli. Considerable conservation of functionally important amino acid residues was revealed. In vivo complementation was done using the R. sphaeroides Che W protein to complement Che W^- strain of E. coli. The R. sphaeroides protein complemented the E. coli strain empirically proving similarity of function of the protein between these widely divergent genera. Homologous recombination using transposon-interrupted genes and internal gene fragments was attempted and met with limited success because R. sphaeroides proved permissive to the suicide vectors used. The most significant result of this study has been not in the similarities revealed between the chemotaxis systems of R. sphaeroides and the enterics, but in the differences discovered. It is now known that R. sphaeroides possesses two Che Y proteins, Che Y and Che Y2, and that whereas the R. sphaeroides Che Y2 protein is closely related to the E. coli Che Y protein, the R. sphaeroides Che Y protein shows considerable evolutionary divergence from it's enteric homologue. The significance of a second copy of Che Y protein suggests that these two response regulators act independently at the motor/switch complex and that they represent the final elements of two functionally distinct chemotactic sensory transduction pathways. This dual pathway system is not present in the enteric bacteria (a member of the γ-group of proteobacteria) but, we propose, may be present in a large group of environmentally important bacteria, the α-group of proteobacteria. Caulobacter, Agrobacterium, Rhizobium and Azospirillum species (α-group proteobacteria) all show behavioural similarities, and there are genetic clues to suggest that these organisms possess a dual chemotactic sensory transduction similar to the one we have found in R. sphaeroides. Apart from being fundamentally important, the dual sensory pathway hypothesis explains the wild-type behaviour of R. sphaeroides, as well as the difficulty in obtaining behavioural mutant phenotypes using methods developed during the investigation of E. coli.

No description available.

Thesis (M.S.) in Animal Sciences--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 59-62).

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 92-109) Also available in print.

Thesis (M.Phil.)--University of Hong Kong, 1998. / Includes bibliographical references. Also available in print.