Includes bibliographical references (leaves 281-328) The experiments reported are investigations of the pituitary of rats stunted by undernutrition imposed between birth and 3 weeks of age.

The neurohypophysial peptide system is involved in modulating a variety of physiological, neurological, and behavioral responses in vertebrates. The principal forms of these peptides in non-mammalian tetrapods are vasotocin (VT) and mesotocin (MT). The studies described in this thesis used pharmacological, molecular, and biochemical techniques, along with phylogenetic analyses, to identify and characterize the mRNA sequences encoding the neurohypophysial peptide precursor proteins and their receptors in urodele amphibians. The cDNAs encoding preproVT and preproMT were amplified by PCR from the brains of two salamander species; the rough-skinned newt, Taricha granulosa, and the red-legged salamander, Plethodon shermani. The neurohypophysial peptides encoded by the identified Taricha cDNAs were VT and MT; the Plethodon cDNAs encoded VT and a novel MT-like peptide, [Val⁴]-MT. Phylogenetic analyses grouped both the Taricha and Plethodon preproVT and preproMT-like sequences with previously identified tetrapod preproVT-like and preproMT-like sequences, respectively. Additional analysis of the preproneurohypophysial sequences indicated that gene conversion (non-homologous crossing over of DNA sequences) appears to have occurred more frequently in mammals than in other tetrapod classes. The cDNAs encoding the VT receptor (VTR) and MT receptor (MTR) were amplified from the brain of T. granulosa by PCR. Sequence identity, and phylogenetic analysis, indicated that the Taricha MTR and VTR were most similar to MTR/OTRs and V[subscript 1a]-like VTRs, respectively. Distribution of PCR amplicons specific to the Taricha MTR and VTR matched previously reported tissue distributions of MTRs and VTRs in other vertebrates in every tissue but kidney, from which the Taricha primers were unable to amplify a cDNA product. Binding experiments of transiently expressed Taricha MTR indicated two binding states, and allowed the determination of ligand binding affinities for this receptor. Inositol phosphate accumulation assays demonstrated that the expressed Taricha MTR and VTR cDNA produced functional receptors, and allowed calculation of ligand potencies of activation and inhibition. Surprisingly, an antagonist frequently used in behavioral experiments to specifically block VTR activity, inhibited inositol phosphate accumulation in cells transfected with either the Taricha MTR or VTR. In conclusion, these studies report the first identified cDNA sequences encoding the preproVT, preproMT, MTR, and V[subscript 1a]-like VTR proteins from urodele amphibians. / Graduation date: 2005

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Marc E. Freeman, Florida State University, Program in Neuroscience. Title and description from dissertation home page (viewed June 8, 2005). Document formatted into pages; contains xi, 172 pages. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Although exocytosis is the major mechanism by which cells secrete products into their environment, little is known about the mechanism of this fundamental process. Previous studies on the regulation of luteinizing hormone (LH) exocytosis have used intact cells exclusively. It is not possible, however, to determine the precise requirements for exocytosis in intact cells since the cytosol is not directly accessible. Permeabilization of the plasma membrane allows experimental manipulation of the intracellular milieu while preserving the exocytic apparatus. The diameter of the atoxin pores (2-3 nm) allowed the exchange of small molecules such as ATP while larger cytosolic proteins such as lactate dehydrogenase were retained. Because of the slow exchange of small molecules through a-toxin pores a protocol was developed which combines prolonged pre-equilibration of the permeabilized cells at 0°C before stimulation with strong Ca²⁺ buffering. Under these conditions an increase in the [Ca²⁺]free stimulated a 15-20 fold increase in LH exocytosis (EC₅₀ pCa 5.5). After 12-15 minutes the rate of exocytosis declined and the cells became refractory to Ca²⁺. At resting [Ca²⁺]free (pea 7), cAMP stimulated a rapid, 2 - 3 fold, increase in LH exocytosis. cAMP caused a modest enhancement of Ca²⁺-stimulated LH exocytosis by causing a left shift in the EC₅₀ for Ca²⁺ from pCa 5.6 to pCa 5.9. Activation of protein kinase C (PKC) with phorbol 12-myristate 13-acetate (PMA) synergistically enhanced cAMP-stimulated LH exocytosis, an effect which was further augmented by increasing the [Ca²⁺]free· Gonadotrophin-releasing hormone (GnRH) was found to stimulate cAMP production in intact pituitary cells. Since previous studies have shown that GnRH activates PKC and stimulates a rise in cytosolic [Ca²⁺]free, these results suggest that a synergistic interaction of the cAMP, PKC and Ca²⁺ second messenger systems is of importance in the mechanism of GnRH-stimulated LH exocytosis. When permeabilized cells were equilibrated for prolonged periods in the absence of MgATP, Ca²⁺-stimulated LH exocytosis declined. The time course of the decline closely followed the leakage of intracellular ¹⁴C-ATP. Addition of MgATP rapidly restored full Ca²⁺-stimulated LH exocytosis. Ca²⁺-, cAMP-, and PMA-stimulated LH exocytosis were all dependent on millimolar MgATP concentrations (EC₅₀ 1 .5-3 mM). It has been postulated that PKC is a mediator of Ca²⁺- stimulated exocytosis. Several findings in the present study argue against this hypothesis. Firstly, PMA and Ca²⁺ had additive effects on LH exocytosis at all [Ca²⁺]free· Secondly, PMA was able to stimulate further LH release from cells made refractory to high [Ca²⁺]free· Thirdly, the PKC inhibitor staurosporine did not inhibit Ca²⁺-stimulated LH exocytosis under conditions in which it inhibited PMAstimulated exocytosis. Fourthly, in cells desensitized to PMA by prolonged exposure to a high PMA concentrations, Ca²⁺-stimulated LH exocytosis was not inhibited. And finally, Ba²⁺+ was able to stimulate LH exocytosis to a maximal extent similar to Ca²⁺ despite the fact that Ba²⁺+ is an extremely poor activator of PKC. Since Ba²⁺+ is also a poor activator of calmodulin, this latter result implies that calmodulin does not mediate the effect of Ca²⁺. In agreement with this, the calmodulin inhibitor calmidazolium did not inhibit Ca²⁺-stimulated LH exocytosis. Since GTP-binding proteins have been implicated in regulated exocytosis in other cell systems, the effects of guanine nucleotides on LH exocytosis were examined. At resting cytosolic [Ca²⁺]free (pea 7), the GTP analogues GTPyS and GMPPNP stimulated LH exocytosis with similar potencies (EC₅₀ 20-50 μM). Additional experiments indicated that the effects of these GTP analogues could not be explained by activation of either PKC alone or cAMP-dependent protein kinase alone. In the presence of both PMA and cAMP, GMPPNP did not stimulate a further increase in the rate of LH exocytosis, suggesting that the stimulatory actions of guanine nucleotides may be mediated by the combined activation of PKC and generation of cAMP, as a result of activation of signal-transducing G proteins. In contrast, pretreatment of cells with GTPyS at low [Ca²⁺]free markedly inhibited subsequent responses to Ca²⁺, cAMP, PMA, and cAMP plus PMA. This inhibitory effect required lower GTPyS concentrations than the stimulatory effect (IC₅₀ 1-10 μM), and was not observed with GMPPNP. These findings indicate the involvement of a distinct guanine nucleotide-binding protein in exocytosis at a site distal to second messenger generation.

No description available.

Preliminary analyses of three kinds of promoter activity showed that a-actin gene promoter was chosen to initiate the hormone transcription for the first consideration. We have fused the cDNAs encoding the intact somatolactins in frame to a zebrafish a-actin gene promoter to generate transgenic zebrafish lines co-injected with a GFP protein driven by the same promoter. The transgenic zebrafish were selected from GFP expression and confirmed by genomic PCR and Southern blot analysis, then maintained as transgenic founders. Measurement of the transgenes' expressions and the expressions of marker genes in different pathways by using real-time PCR provided a general understanding of SLs' actions. The data obtained indicated that the over-expressing of SLalpha and SLbeta in vivo significantly enhance the transcriptions of the insulin-like growth factors, IGF1 (5.46-fold and 6.77-fold), IGF2a (4.38-fold and 4.35-fold) and IGF2b (2.83-fold and 3.94-fold), but down-regulated IGF3 (a novel member found specifically in gonad) in larvae. However, the stimulation by administration of recombinant proteins (SLalpha and SLbeta) only showed a slight induction of the mRNA levels of IGFs (IGF1, IGF2a and IGF2b) on ZFL cells in vitro. / Somatolactin (SL) is a novel member of pituitary polypeptide hormone found only in fish; it shares significant structural homology with prolactin and growth hormone. Since somatolactin receptor (SLR) was first defined as GHR1 and orthologous to the growth hormone receptor GHR2, SL and GH may share similar actions in growth and development. Recently, two SLs have been identified as SLalpha and SLbeta with similar structures, freshwater fish have these two isoforms found in the same species and only one isoform (SLalpha) is found in marine species. The two isoforms of SL may have different functions and physiological actions. To investigate the roles of SLs on vertebrate development and embryogenesis, we generated transgenic fish models with "all zebrafish" elements in origin to study the physiological functions of SLs in zebrafish. / The ectopic expression of somatolactins also results in up-regulating gene expression of insulin, leptin, sterol regulatory element binding protein 1 (SREBP1) and fatty acid synthase (FAS), as well as the expression of vitellogenin and melanocyte-stimulating hormone (MSH) levels while causing reduction of catalase (CAT) and glutathione S-transferase (GST) levels in larvae. The results here represent the similar function between SLalpha and SLbeta and reveal more details in fish of the endocrinology system involvement in growth development, glucose synthesis, lipid metabolism, reproduction, pigmentation and antioxidant defense system through the actions of SLs. / Three different gene promoters of zebrafish have been isolated to initiate the ectopic expression of somatolactins in vivo, which including a constitutional beta-actin gene promoter, a liver specific transferrin gene promoter and a zinc ion inducible metallothionein (MT) gene promoter. The promoter activities were tested in fish cell-line by using luciferase reporter assay. In MT gene promoter, two alleles of a zebrafish metallothionein II gene (zMT-II) promoter (zMT-IIA and zMT-IIB) containing 10 MREs in the 5'-flanking region (1,514 bp) were identified in zebrafish. These putative MREs were confirmed via electrophoretic mobility shift assay (EMSA) to have binding activities from the cellular and nuclear extracts of a zebrafish cell line, ZFL. Transient gene expression studies using zebrafish liver (ZFL) cell lines also confirmed that the most distal cluster of MREs contributed to the maximal induction of zMT-IIA activity by Zn2+ and the Zn 2+ induction was dose-dependent. EMSA also identified transcription factor(s) of two different sizes from the cytoplasmic and nuclear extracts of the ZFL cells that were able to bind with the MREs, but no increase in MRE binding was detected in the extracts of these cells after Zn2+ or Cd2+ treatment, compared with untreated control cells. The mechanisms of MT gene transcription induction via metal ions are discussed herein. / Wan, Guohui. / Adviser: Chan King Ming. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 139-163). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1940. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 180-182).

by Yeung Sze Mang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 123-133). / Abstracts in English and Chinese. / ACKNOWLEDGMENTS --- p.i / ABSTRACT --- p.ii / 槪論 --- p.iii / ABBREVIATIONS --- p.iv / AMINO ACIDS SHORTHAND --- p.vi / TABLE OF CONTENTS --- p.vii-x / Chapter CHAPTER 1 --- LITERATURE REVIEW / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Structural Analysis of SL --- p.1 / Chapter 1.3 --- Location of SL-producing cells and Expression of SL --- p.5 / Chapter 1.4 --- Possible Functions of SL --- p.9 / Chapter 1.4.1 --- Adaptation to various backgrounds and Intensities of Illuminations --- p.9 / Chapter 1.4.2 --- Control of Reproduction and Maturation --- p.10 / Chapter 1.4.3 --- Responses to Stress --- p.12 / Chapter 1.4.4 --- Regulation of P034- and Ca2+ Metabolism --- p.12 / Chapter 1.4.5 --- Acid - Base Balance --- p.14 / Chapter 1.4.6 --- Regulation of Energy Metabolism --- p.15 / Chapter 1.4.7 --- Regulation of Fat Metabolism --- p.15 / Chapter 1.5 --- Regulation of SL Gene Expression --- p.19 / Chapter 1.5.1 --- Pit-1 Related Gene Regulation --- p.19 / Chapter 1.5.2 --- Regulation of Hormone Secretion --- p.21 / Chapter 1.5.2.1 --- Hypothalamic Factors --- p.21 / Chapter 1.5.2.2 --- Steroids --- p.23 / Chapter 1.6 --- Aims of Thesis --- p.23 / Chapter 1.6.1 --- Identification of SLII from Goldfish (Carassius auratus) --- p.23 / Chapter 1.6.2 --- Aims --- p.27 / Chapter CHAPTER 2 --- PCR ANALYSIS OF GFSLII GENE AND ITS EXPRESSION IN GOLDFISH TISSUE / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.2 --- Materials and Methods --- p.31 / Chapter 2.2.1 --- Materials --- p.31 / Chapter 2.2.2 --- Methods --- p.33 / Chapter 2.2.2.1 --- Subcloning and DNA Sequencing of the Goldfish SLII Amplified by PCR --- p.33 / Chapter 2.2.2.1.1 --- PCR Cloning of Goldfish SLII Gene --- p.33 / Chapter 2.2.2.1.2 --- Restriction Enzyme Digestion of the PCR Clones --- p.33 / Chapter 2.2.2.1.3 --- Subcloning of the Digested Fragments --- p.33 / Chapter 2.2.2.1.4 --- DNA Sequencing of the Subcloned Fragments --- p.34 / Chapter 2.2.2.2 --- Tissue Distribution Studies Using RNA Assay --- p.35 / Chapter 2.2.2.2.1 --- Tissue Preparation --- p.35 / Chapter 2.2.2.2.2 --- Total RNA Extraction --- p.35 / Chapter 2.2.2.2.3 --- Electrophoresis of RNA in Formadehyde Agarose Gel --- p.36 / Chapter 2.2.2.2.4 --- First Strand cDNA Synthesis --- p.37 / Chapter 2.2.2.2.5 --- Goldfish SLII Specific PCR --- p.37 / Chapter 2.2.2.2.6 --- PCR to Test DNA Contamination --- p.38 / Chapter 2.3 --- Results --- p.39 / Chapter 2.3.1 --- Subcloning and DNA Sequencing of the Goldfish SLII Amplified by PCR --- p.39 / Chapter 2.3.2 --- Tissue Distribution Studies Using RNA Assay --- p.40 / Chapter 2.4 --- Discussion --- p.45 / Chapter 2.4.1 --- Subcloning and DNA Sequencing of the Goldfish SLII Amplified by PCR --- p.45 / Chapter 2.4.2 --- Tissue Distribution Studies Using RNA Assay --- p.46 / Chapter CHAPTER 3 --- ANALYSIS OF GOLDFISH SLII GENE / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- Materials and Methods --- p.49 / Chapter 3.2.1 --- Materials --- p.49 / Chapter 3.2.2 --- Methods --- p.54 / Chapter 3.2.2.1 --- Screening of Goldfish Genomic Library --- p.54 / Chapter 3.2.2.1.1 --- Preparation of the Plating Host --- p.54 / Chapter 3.2.2.1.2 --- Preparation of the Probe --- p.54 / Chapter 3.2.2.1.3 --- Primary Screening of Goldfish Genomic Library --- p.55 / Chapter 3.2.2.1.4 --- Isolation of the Positive Clones --- p.56 / Chapter 3.2.2.1.5 --- Phage Titering --- p.56 / Chapter 3.2.2.1.6 --- Purification of the Positive Clones --- p.57 / Chapter 3.2.2.1.7 --- Phage DNA Preparation --- p.57 / Chapter 3.2.2.1.8 --- Find out the Target Gene Size of the Positive Clones --- p.58 / Chapter 3.2.2.1.9 --- Cloning of the PCR Fragments into pUC18 Vector --- p.59 / Chapter 3.2.2.1.10 --- Checking the Cloned Insert Size --- p.60 / Chapter 3.2.2.1.11 --- Restriction Enzyme Digestion to Release the Inserts --- p.61 / Chapter 3.2.2.1.12 --- Mini prep of the Positive Clones for Further Investigations --- p.61 / Chapter 3.2.2.1.13 --- DNA Sequencing of the Positive Clones --- p.61 / Chapter 3.2.2.1.14 --- Restriction Enzyme Mapping of the Positive Clones --- p.62 / Chapter 3.2.2.1.15 --- Subcloning of Clone 2A and5A / Chapter 3.2.2.1.16 --- Determination of the Promoter Region of Clone 2A Using Universal Genome Walker Kit --- p.63 / Chapter 3.2.2.2 --- Southern Blot Analysis of Goldfish and Catfish Genomic DNA --- p.66 / Chapter 3.2.2.2.1 --- Genomic DNA Preparation from Goldfish and Catfish Tissues --- p.66 / Chapter 3.2.2.2.2 --- Restriction Enzyme Digestion of the Genomic DNA --- p.67 / Chapter 3.2.2.2.3 --- Alkaline Transfer of the Digested Genomic DNA --- p.67 / Chapter 3.2.2.2.4 --- Hybridization of the Digested Genomic DNA --- p.67 / Chapter 3.3 --- Results --- p.69 / Chapter 3.3.1 --- Screening of the Goldfish Genomic Library --- p.69 / Chapter 3.3.2 --- Mapping the Target Genes --- p.69 / Chapter 3.3.3 --- DNA Sequencing of the 2 Positive Clones --- p.69 / Chapter 3.3.4 --- Southern Blot Analysis of Goldfish and Catfish Genomic DNA --- p.81 / Chapter 3.4 --- Discussion --- p.83 / Chapter CHAPTER 4 --- EXPRESSION OF RECOMBINANT GOLDFISH SOMATOLACTIN IN ESCHERICHIA COLI (E. COLI) / Chapter 4.1 --- Introduction --- p.87 / Chapter 4.2 --- Materials and Methods --- p.89 / Chapter 4.2.1 --- Materials --- p.89 / Chapter 4.2.2 --- Methods --- p.96 / Chapter 4.2.2.1 --- Transformation of the Recombinant Protein Carrying Plasmid into E. coli. (BL21) --- p.96 / Chapter 4.2.2.2 --- Small Scale Expression of Recombinant Goldfish SLII Protein --- p.96 / Chapter 4.2.2.3 --- Large Scale Expression of Recombinant Goldfish SLII Protein --- p.97 / Chapter 4.2.2.4 --- Preparation of the Recombinant Protein for Purification --- p.99 / Chapter 4.2.2.5 --- Protein Purification Using Novagen His-Bind Resin Kit --- p.99 / Chapter 4.2.2.6 --- Production of Polyclonal Antibody in Rabbits --- p.100 / Chapter 4.2.2.7 --- Enzyme Linked Immunosorbant Assay (ELISA) --- p.101 / Chapter 4.2.2.8 --- Western Blot Analysis of the Recombinant Hormones --- p.103 / Chapter 4.3 --- Results --- p.105 / Chapter 4.3.1 --- Expression of the Recombinant Goldfish SLII --- p.105 / Chapter 4.3.2 --- Purification of the Recombinant Goldfish SLII --- p.105 / Chapter 4.3.3 --- ELISA Analysis --- p.105 / Chapter 4.3.4 --- Western Blot Analysis --- p.110 / Chapter 4.4 --- Discussion --- p.113 / Chapter 4.4.1 --- Expression of the Recombinant Goldfish SLII --- p.113 / Chapter 4.4.2 --- Purification of the Recombinant Goldfish SLII --- p.114 / Chapter 4.4.3 --- Analysis of the Recombinant Goldfish SLII --- p.114 / Chapter CHAPTER 5 --- GENERAL DISCUSSION AND CONCLUSIONS --- p.116 / REFERENCES --- p.123

published_or_final_version / Zoology / Master / Master of Philosophy