No description available.

Goldfish (Carassius auratus) (40-80g) were injected with dopamine into the forebrain to study the possible involvement of this amine in central temperature regulation in these fish. Dopamine caused a decrease in selected temperature after injection into the rostral nucleus preopticus periventricularis (NPP). This effect was dependent on the dose of dopamine administered. Doses of 25, 50, 100 and 250 ng were used, injected in a volume of 0.2μ1. Injections in regions adjacent to the NPP elicited hypothermic effects only at the higher dosages. These effects were not consistent. Injections in caudal regions of the NPP elicited no effect. The effects of dopamine were blocked by haloperidol, a selective antagonist of dopamine. It is suggested that dopamine acts on central thermoregulatory neurons, present in the rostral NPP, in the mediation of thermoregulatory behavior. Further, it is suggested that this action is mediated via dopaminergic receptors.

Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°c, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In both species of fish, lower acclimation temperatures and increased time spent at low temperatures caused a preference for lower temperatures in the gradient.

No description available.

No description available.

No description available.

No description available.

Ko Nga Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 98-131). / Abstracts in English and Chinese. / Abstract (in English) --- p.ii / Abstract (in Chinese) --- p.v / Acknowledgements --- p.vii / Table of Contents --- p.ix / List of Figures --- p.xiv / List of Tables --- p.xvii / Symbols and Abbreviations --- p.xviii / Scientific Names --- p.xxi / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Gonadotropins --- p.1 / Chapter 1.1.1 --- Structure --- p.1 / Chapter 1.1.2 --- Function --- p.3 / Chapter 1.1.3 --- Regulation --- p.5 / Chapter 1.1.3.1 --- Hypothalamic regulators (GnRH) --- p.5 / Chapter 1.1.3.2 --- Endocrine regulators from gonads (steroids) --- p.7 / Chapter 1.1.3.3 --- Paracrine regulators (activin) --- p.9 / Chapter 1.1.4 --- Promoter analysis --- p.9 / Chapter 1.2 --- Activin Family of Growth Factors --- p.12 / Chapter 1.2.1 --- Activin --- p.12 / Chapter 1.2.1.1 --- Structure --- p.12 / Chapter 1.2.1.2 --- Function --- p.13 / Chapter 1.2.1.3 --- Signaling --- p.15 / Chapter 1.2.2 --- Follistatin --- p.16 / Chapter 1.2.2.1 --- Structure --- p.16 / Chapter 1.2.2.2 --- Function --- p.17 / Chapter 1.3 --- Objectives --- p.18 / Chapter Chapter 2 --- Establishment and Characterization of Stable LβT2 Cell Lines Containing and Expressing SEAP Driven by the Goldfish FSHβ Promoter / Chapter 2.1 --- Introduction --- p.29 / Chapter 2.2 --- Materials and Methods --- p.31 / Chapter 2.2.1 --- Construction of expression plasmid --- p.31 / Chapter 2.2.2 --- Cell culture --- p.32 / Chapter 2.2.3 --- Cotransfection of LβT2 cells --- p.32 / Chapter 2.2.4 --- G418 selection of transfected LpT2 cells --- p.33 / Chapter 2.2.5 --- SEAP reporter gene assay --- p.33 / Chapter 2.2.6 --- Cloning of pSEAP/gfFSHβ promoter and pBK- CMV-transfected LβT2 cells by limited dilution --- p.34 / Chapter 2.2.7 --- Extraction of genomic DNA --- p.34 / Chapter 2.2.8 --- Isolation of total RNA --- p.35 / Chapter 2.2.9 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.35 / Chapter 2.3 --- Results --- p.36 / Chapter 2.3.1 --- Optimization of G418 concentration for selection --- p.36 / Chapter 2.3.2 --- Expression of SEAP reporter gene by pSEAP/gfFSHβ promoter and pBK-CMV-transfected LβT2 cells --- p.37 / Chapter 2.3.3 --- Establishment of LβT2 cell lines that contain a functional gfFSHp promoter --- p.37 / Chapter 2.3.4 --- Characterization of LβT2#23 that contains a functional gfFSHβ promoter --- p.38 / Chapter 2.4 --- Discussion --- p.39 / Chapter Chapter 3 --- Hormonal Regulation of Goldfish Follicle-Stimulating Hormone β (FSHβ) Promoter Activity in LpT2#23 Cells / Chapter 3.1 --- Introduction --- p.52 / Chapter 3.2 --- Materials and Methods --- p.54 / Chapter 3.2.1 --- Cell culture --- p.55 / Chapter 3.2.2 --- Drug treatment --- p.56 / Chapter 3.2.3 --- SEAP reporter gene assay --- p.56 / Chapter 3.2.4 --- Isolation of total RNA --- p.57 / Chapter 3.2.5 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.57 / Chapter 3.2.6 --- Data analysis --- p.58 / Chapter 3.3 --- Results --- p.59 / Chapter 3.3.1 --- Effects of goldfish activin on FSHβ promoter --- p.59 / Chapter 3.3.2 --- Blockade of activin effects by follistatin --- p.59 / Chapter 3.3.3 --- Effects of different hormones and steroids on FSHβ promoter --- p.60 / Chapter 3.4 --- Discussion --- p.61 / Chapter Chapter 4 --- Promoter Analysis for the Activin Responsive Element (ARE) in the Goldfish Follicle-Stimulating Hormone β (FSHβ) Gene / Chapter 4.1 --- Introduction --- p.71 / Chapter 4.2 --- Materials and Methods --- p.74 / Chapter 4.2.1 --- Generation of SEAP reporter plasmids containing the gfFSHβ promoter of different lengths --- p.74 / Chapter 4.2.2 --- PCR screening and restriction analysis --- p.75 / Chapter 4.2.3 --- Midiprep --- p.76 / Chapter 4.2.4 --- Cell culture --- p.77 / Chapter 4.2.5 --- Transfection of the pSEAP/gfFSHβ promoter constructs into LβT2 cells --- p.77 / Chapter 4.2.6 --- Activin treatment --- p.77 / Chapter 4.2.7 --- SEAP assay --- p.78 / Chapter 4.3 --- Results --- p.78 / Chapter 4.3.1 --- Subcloning of the gfFSHβ promoter of decreasing length into SEAP reporter vector --- p.78 / Chapter 4.3.2 --- Activin stimulation of the pSEAP/gfFSHβ promoter constucts in LβT2 cells --- p.79 / Chapter 4.4 --- Discussion --- p.80 / Chapter Chapter 5 --- General Discussion / Chapter 5.1 --- Overview --- p.92 / Chapter 5.2 --- Contribution of the present research --- p.95 / Chapter 5.2.1 --- Establishment of stable LβT2 cell lines containing and expressing SEAP driven by gfFSHβ promoter --- p.95 / Chapter 5.2.2 --- Hormonal regulation of the gfFSHβ promoterin LβT2#23 cells --- p.95 / Chapter 5.2.3 --- Identification of the activin responsive element (ARE) on the gfFSHβ promoter --- p.96 / Chapter 5.3 --- Future research direction --- p.96 / References --- p.98

Cheng Fu Yip Gheorghe. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 97-116). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract (in English) --- p.III / Abstract (in Chinese) --- p.V / Table of Content --- p.VII / Symbols and Abbreviations --- p.XII / Scientific Names --- p.XIV / List of Tables --- p.XV / List of Figures --- p.XVI / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Gonadotropin / Chapter 1.1.1 --- Structure --- p.2 / Chapter 1.1.2 --- Function --- p.3 / Chapter 1.1.3 --- Regulation --- p.4 / Chapter 1.1.3.1 --- Neuroendocrine and endocrine regulation of GTHs --- p.4 / Chapter 1.1.3.1.1 --- Hypothalamic neuropeptides and neurotransmitters --- p.6 / Chapter 1.1.3.1.2 --- Gonadal steroids --- p.7 / Chapter 1.1.3.2 --- Paracrine regulation of GTH --- p.8 / Chapter 1.2 --- Activin / Chapter 1.2.1 --- Structure --- p.8 / Chapter 1.2.2 --- Function --- p.9 / Chapter 1.2.3 --- Regulation of activin activity --- p.12 / Chapter 1.2.3.1 --- Intracellular blockade of activin signaling by Smad7 --- p.12 / Chapter 1.2.3.2 --- Extracellular control of activin access --- p.13 / Chapter 1.2.3.2.1 --- Inhibin --- p.13 / Chapter 1.2.3.2.2 --- Activin-binding protein --- p.14 / Chapter 1.3 --- Follistatin / Chapter 1.3.1 --- Structure --- p.14 / Chapter 1.3.2 --- Function --- p.16 / Chapter 1.3.3 --- Regulation in the pituitary --- p.19 / Chapter 1.4 --- Objectives of the Present Study --- p.20 / Chapter Chapter 2 --- Cloning and Recombinant Production of Goldfish Follistatin / Chapter 2.1 --- Introduction --- p.24 / Chapter 2.2 --- Materials and Methods / Chapter 2.2.1 --- Reagents --- p.26 / Chapter 2.2.2 --- Animal --- p.26 / Chapter 2.2.3 --- Extraction of total RNA and reverse transcription --- p.27 / Chapter 2.2.4 --- Cloning of full-length cDNA encoding goldfish follistatin --- p.27 / Chapter 2.2.5 --- Sequencing of the cDNA --- p.29 / Chapter 2.2.6 --- Distribution of follistatin mRNA in different tissues --- p.29 / Chapter 2.2.7 --- Production of rgFS --- p.30 / Chapter 2.2.8 --- RT-PCR of the rgFS-positive clones --- p.34 / Chapter 2.2.9 --- Extraction of genomic DNA from rgFS-positive clones --- p.34 / Chapter 2.2.10 --- Functional analysis of rgFS --- p.35 / Chapter 2.2.11 --- Data Analysis --- p.37 / Chapter 2.3 --- Results / Chapter 2.3.1 --- Cloning and sequence analysis of goldfish follistatin --- p.37 / Chapter 2.3.2 --- Tissue distribution of follistatin mRNA in the goldfish --- p.39 / Chapter 2.3.3 --- Production and bioassay of rgFS --- p.43 / Chapter 2.4 --- Discussion --- p.47 / Chapter Chapter 3 --- Function and Regulation of Follistatin in the Goldfish Pituitary; Evidence for an Intrinsic Activin/Follistatin Regulatory Feedback Loop / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Materials and Methods / Chapter 3.2.1 --- Reagents --- p.57 / Chapter 3.2.2 --- Animals --- p.57 / Chapter 3.2.3 --- Primary culture of dispersed pituitary cells --- p.57 / Chapter 3.2.4 --- RNA extraction and reverse transcription --- p.58 / Chapter 3.2.5 --- Ovariectomy on pituitary follistatin expression --- p.5 9 / Chapter 3.2.6 --- Seasonal expression profile of follistatin --- p.59 / Chapter 3.2.7 --- Validation of semi-quantitative RT-PCR assays --- p.61 / Chapter 3.2.8 --- Real-time PCR for assay on follistatin and β-actin expression --- p.61 / Chapter 3.2.9 --- Data analysis --- p.63 / Chapter 3.3 --- Results / Chapter 3.3.1 --- Expression of follistatin in the goldfish pituitary --- p.64 / Chapter 3.3.2 --- Validation of semi-quantitative RT-PCR assay --- p.64 / Chapter 3.3.3 --- Activin regulation of pituitary follistatin --- p.64 / Chapter 3.3.4 --- Effects of sex steroids on pituitary follistatin expression --- p.69 / Chapter 3.3.5 --- Effect of GnRH on follistatin expression in the pituitary --- p.74 / Chapter 3.3.6 --- Effect of intracellular cAMP level on pituitary follistatin expression --- p.74 / Chapter 3.3.7 --- Seasonal variation profile of goldfish pituitary follistatin --- p.78 / Chapter 3.4 --- Discussion --- p.78 / Chapter Chapter 4 --- General Discussion / Chapter 4.1 --- Overview --- p.89 / Chapter 4.2 --- Contribution of the Present Study / Chapter 4.2.1 --- Cloning of full-length goldfish follistatin cDNA --- p.91 / Chapter 4.2.2 --- Establishment of stable cell line for expression of rgFS --- p.92 / Chapter 4.2.3 --- Evidence for the presence of intrinsic feedback loop of activin in the goldfish pituitary --- p.92 / Chapter 4.2.4 --- Modulation of follistatin expression in the pituitary by sex steroids --- p.93 / Chapter 4.2.5 --- Conclusions --- p.93 / Chapter 4.3 --- Future Prospects / Chapter 4.3.1 --- Production of rgFS --- p.95 / Chapter 4.3.2 --- Regulation of activin-follistatin system in the pituitary --- p.95 / Reference --- p.96

Pang Yee Man Flora. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 111-128). / Abstracts in English and Chinese. / Abstract (in English) --- p.ii / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.v / Table of Contents --- p.vii / List of Figures --- p.xii / Symbols and Abbreviations --- p.xv / Scientific Names --- p.xvii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Vitellogenesis --- p.2 / Chapter 1.2 --- Vitellogenin --- p.3 / Chapter 1.2.1 --- Structure --- p.3 / Chapter 1.2.2 --- Vitellogenin synthesis in the liver --- p.4 / Chapter 1.3 --- Regulation of vitellogenin synthesis --- p.5 / Chapter 1.3.1 --- Estradiol --- p.5 / Chapter 1.3.1.1 --- Mechanism of action --- p.6 / Chapter 1.3.1.2 --- Estradiol-stimulated vitellogenin expression --- p.7 / Chapter 1.3.1.3 --- Memory effects --- p.9 / Chapter 1.3.2 --- Testosterone --- p.10 / Chapter 1.3.3 --- Cortisol --- p.13 / Chapter 1.3.4 --- Progesterone --- p.14 / Chapter 1.3.5 --- Growth Hormone --- p.14 / Chapter 1.3.6 --- Prolactin --- p.15 / Chapter 1.3.7 --- Thyroid hormone --- p.15 / Chapter 1.4 --- Growth factors --- p.16 / Chapter 1.4.1 --- Activin --- p.16 / Chapter 1.4.1.1 --- Structure --- p.16 / Chapter 1.4.1.2 --- Functions --- p.17 / Chapter 1.4.2 --- Epidermal growth factors (EGF) --- p.18 / Chapter 1.4.2.1 --- Structure --- p.18 / Chapter 1.4.2.2 --- Functions --- p.19 / Chapter 1.5 --- Objectives of the present study --- p.20 / Chapter Chapter 2 --- Expression of Goldfish Vitellogenin in vivo and in vitro --- p.25 / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Materials and Methods --- p.26 / Chapter 2.2.1 --- Materials --- p.26 / Chapter 2.2.2 --- Sequencing --- p.27 / Chapter 2.2.3 --- Cell culture --- p.28 / Chapter 2.2.4 --- RNA extraction --- p.29 / Chapter 2.2.5 --- Northern hybridization --- p.31 / Chapter 2.2.6 --- Slot blot hybridization --- p.32 / Chapter 2.2.7 --- Data analysis --- p.33 / Chapter 2.2.8 --- SDS-PAGE analysis --- p.33 / Chapter 2.2.9 --- in situ hybridization --- p.34 / Chapter 2.3 --- Results --- p.37 / Chapter 2.3.1 --- Validation of vitellogenin mRNA detection --- p.37 / Chapter 2.3.2 --- Basal and estradiol-stimulated vitellogenin expression and production invivo --- p.38 / Chapter 2.3.3 --- Localization of vitellogenin expression in the liver --- p.39 / Chapter 2.3.4 --- Expression of vitellogenin in vitro --- p.40 / Chapter 2.4 --- Discussion --- p.54 / Chapter Chapter 3 --- Effects of Steroids on the Expression of Goldfish Vitellogenin in vitro --- p.60 / Chapter 3.1 --- Introduction --- p.60 / Chapter 3.2 --- Materials and Methods --- p.62 / Chapter 3.2.1 --- Materials --- p.62 / Chapter 3.2.2 --- Animal --- p.62 / Chapter 3.2.3 --- Primary culture of dispersed hepatic cells --- p.62 / Chapter 3.2.4 --- Drug treatment --- p.64 / Chapter 3.2.5 --- Total RNA isolation --- p.64 / Chapter 3.2.6 --- Messenger RNA isolation --- p.65 / Chapter 3.2.7 --- Slot blot analysis --- p.66 / Chapter 3.2.8 --- Data analysis --- p.68 / Chapter 3.2.9 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.68 / Chapter 3.2.10 --- Cloning of aromatase cDNA --- p.69 / Chapter 3.2.11 --- Sequencing --- p.70 / Chapter 3.3 --- Results --- p.71 / Chapter 3.3.1 --- Effect of 17-β estradiol on vitellogenin mRNA expression --- p.71 / Chapter 3.3.2 --- Effect of testosterone on vitellogenin mRNA expression --- p.71 / Chapter 3.3.3 --- Detection of aromatase mRNA expression in the liver by RT-PCR --- p.72 / Chapter 3.3.4 --- Effect of aromatase inhibitors on testosterone-stimulated vitellogenin expression --- p.73 / Chapter 3.4 --- Discussion --- p.81 / Chapter Chapter 4 --- Effects of Epidermal Growth Factor (EGF) and Activin on the Expression of Vitellogenin in the Goldfish Hepatic Cells in vitro --- p.86 / Chapter 4.1 --- Introduction --- p.86 / Chapter 4.2 --- Materials and Methods --- p.88 / Chapter 4.2.1 --- Materials --- p.88 / Chapter 4.2.2 --- Primary culture of dispersed hepatic cells --- p.89 / Chapter 4.2.3 --- Slot blot analysis --- p.91 / Chapter 4.2.4 --- Data analysis --- p.91 / Chapter 4.3 --- Results --- p.92 / Chapter 4.3.1 --- Effect of activin on vitellogenin mRNA expression --- p.92 / Chapter 4.3.2 --- Effect of EGF and TGF-α on vitellogenin mRNA expression --- p.93 / Chapter 4.4 --- Discussion --- p.99 / Chapter Chapter 5 --- General Discussion --- p.104 / Chapter 5.1 --- Overview --- p.104 / Chapter 5.2 --- Contribution of the present study --- p.106 / Chapter 5.2.1 --- Expression of goldfish vitellogenin in vivo and in vitro --- p.106 / Chapter 5.2.2 --- Effects of steroids on the expression of goldfish vitellogenin in vitro --- p.106 / Chapter 5.2.3 --- Effects of EGF and activin on the expression of vitellogenin in the goldfish hepatic cells in vitro --- p.107 / Chapter 5.3 --- Future prospects --- p.108