Freshwater lake ecosystems often exhibit strong oxygen, and temperature gradients across which many zooplankton species live. Daphnia sp. vary in their ability to up-regulate hemoglobin in response to low oxygen environments. However; the role that hemoglobin up-regulation plays in diel vertical migration, and how it might mediate coexistence of Daphnia within lakes is still unclear. Using an oligotrophic lake in Ontario, I studied three distinct phenotypes of Daphnia pulicaria, which differed in the ability to up-regulate hemoglobin (classified as red, pink, and pale). Twenty-four hour surveys were conducted during the fall of 2012 and samples were drawn at 1m intervals to monitor changes in diel vertical migration. At each 1m interval Daphnia were color indexed, photographed, and preserved for genetic analysis using cellulose acetate electrophoresis. Red and pink Daphnia showed little change in distribution over the water column through time, suggesting individuals experienced little vertical migration. Pale individuals showed strong changes in vertical distribution through time suggesting vertical migration. The phenotypes are strongly correlated with multi-locus genotypes, suggesting genetic differences in migration behavior. Mesocosm experiments were used to manipulate migration over heterogeneous environments to test the hypothesis that vertical migration impacts genetic and phenotypic diversity in Daphnia pulicaria. The first mesocosm experiment contained two treatment groups; a migrating and non-migrating treatment containing the three phenotypes. The migrating treatment permitted unrestricted movement throughout the water column, and the non-migrating treatment restricted Daphnia to discrete 1m intervals. The second mesocosm experiment comprised two non-migrating treatments; red non-migrating and pale non-migrating. Results from the first set of mesocosm experiments indicate decreased genetic and phenotypic diversity in the migrating treatment. Shifts in hemoglobin up-regulation between pales and reds in the second mesocosm experiments suggest hemoglobin up-regulation is plastic, whereby pale, pink, and red individuals have the ability to up and down regulate hemoglobin. The differences in Daphnia migration patterns and the plastic response in hemoglobin up-regulation permits migrating genotypes to withstand low oxygen conditions. Overall implications of this study suggest that migration over a strong environmental gradient plays a key role in fostering phenotypic plasticity and genetic diversity in organisms living in heterogeneous environments. / Thesis (Master, Biology) -- Queen's University, 2014-04-08 12:07:42.757

No description available.

Hemoglobins (Hbs) are heme-containing proteins belonging to the globin superfamily that are ubiquitous in most living organisms including prokaryotes and eukaryotes. In addition to the first legHbs found in leguminous plants, there are another three classes of phytoglobins (Pgbs) identified in various plant species including dicots and monocots. The ability of heme groups to bind gaseous ligands such as oxygen, carbon monoxide and nitric oxide (NO) places Pgbs as multifunctional players in various processes during plant growth and development under normal or stress conditions. The objective of this project is to investigate how transcriptional manipulation of ZmPgb1.1 and ZmPgb1.2 influences somatic embryogenesis in maize (Zea mays). Suppression of either of the two genes is sufficient to induce programmed cell death (PCD) through a pathway initiated by accumulation of nitric oxide (NO) and zinc (Zn2+), and mediated by production of reactive oxygen species (ROS). The effect of the death program on the fate of the developing embryos is dependent upon the localization patterns of the two Pgbs. During somatic embryogenesis, ZmPgb1.2 transcripts are restricted to a few cells anchoring the embryos to the subtending embryogenic tissue, while ZmPgb1.1 transcripts extend to several embryonic domains. Suppression of ZmPgb1.2 induces PCD in the anchoring cells allowing the embryos to develop further, while suppression of ZmPgb1.1 results in massive PCD leading to embryo abortion. Cells suppressing the Pgb genes are also depleted of endogenous auxin (indole-3-acetic acid, IAA) localization established by polar auxin transport (PAT), thus suggesting a possible involvement of this plant hormone in the observed processes. Collectively, it appears that the cell specific expression of Pgbs has the capability to determine the developmental fate of embryogenic tissue during maize somatic embryogenesis through their effect on PCD. This novel regulation has implications for development and differentiation in other species.

Syre transporteras från lungorna, via blodet bundet till erytrocyternas hemoglobin, till kroppens alla celler. En hemoglobinkoncentration i blodet under referensintervallet definieras som anemi och påverkar hela kroppen och försämrar den fysiska prestationsförmågan. Järnbristanemi är en anemi med otillräcklig järntillförsel till benmärgen på grund av tomma järnförråd (absolut järnbrist) eller försvårat järnutnyttjande (funktionell järnbrist). Analysparametern HYPO på analysinstrumentet Advia 2120 (Siemens) mäter andelen hypokroma erytrocyter (erytrocyter med lågt hemoglobininnehåll) och anses vara en av de bästa parametrarna för att påvisa funktionell järnbrist. Analysparametern Hypo-He på analysinstrumentet XN-1000 (Sysmex) är en forskningsparameter för samma ändamål. Syftet med detta arbete var att jämföra markörer för funktionellt järnstatus och utvärdera om analysen HYPO på Advia 2120 kan ersättas med Hypo-He på XN-1000. Fyrtiofyra patientprover, på vilka HYPO var beställt, analyserades, först på XN-1000 och därefter på Advia 2120. En linjär regressionmodell gjordes för att beskriva korrelationen mellan analyserna HYPO och Hypo-He. Imprecisionen för analysen Hypo-He beräknades genom inom-serie- och total-serie-imprecision. Korrelationen mellan analyserna var måttligt stark (r = 0,7185 (absoluta värden) och r = 0,8081 (logaritmerade värden)), dock med många analysresultat inom det lägre området. Variationskoefficienten för Hypo-He beräknades till mellan 0 % - 9,5 %. För att kunna avgöra om Hypo-He kan ersätta HYPO som indikator på funktionell järnbrist krävs kompletterande studier på välkaraktäriserade patientprover med varierande analysvärden inkluderande värden för HYPO på mer än 10 %.

To mimic the properties of haemoglobin (Hb) and myoglobin (Mb) it has been found necessary to synthesise a five-coordinate ferrous porphyrin with a protecting structure over the sixth coordination site at iron. This thesis describes approaches to the synthesis of such a compound where the protecting structure is the "capped" moiety and where the base which occupies the fifth coordination site is held in position by two covalent linkages to the porphyrin. The preparation of the target molecule involved the synthesis of a new "capped" porphyrin and a series of difuncticnalised pyridines. These were then successfully coupled under high dilution conditions to give the "capped/strapped" porphyrin. Metallation and reduction completed the synthesis. The behaviour of the ferrous complex in the presence of dioxygen was investigated. High stability toward irreversible oxidation was found. In the presence of oxygen the ferrous complex had a half-life in excess of 40h at room temperature.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 92-98).

Thesis (M.S.)--Florida State University, 2005. / Advisor: Timothy Logan, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Feb. 1, 2006). Document formatted into pages; contains viii, 37 pages. Includes bibliographical references.

Thesis (M.S.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: David J. Singel. Includes bibliographical references (leaves 55-56).

Orientador: Patrícia Soares Santiago / Banca: Regildo Márcio Gonçalves da Silva / Banca: Célia Sulzbacher Caruso / Resumo: As hemoglobinas constituem um grupo de proteínas que desempenham um papel vital nos organismos. Suas propriedades intrínsecas, assim como a sua relação estrutura-atividade, envolvem fenômenos tais como a cooperatividade e afinidade por ligantes específicos, como o oxigênio, que estão associados a uma variedade de processos que viabilizam a vida. As hemoproteínas, em especial as hemoglobinas de anelídeos têm sido objeto de estudo de diferentes grupos de pesquisa, devido a sua alta estabilidade oligomérica, resistência à oxidação, alta cooperatividade e afinidade por ligantes específicos, apresentando um alto potencial em aplicações biotecnológicas como, por exemplo, substituto sanguíneo. Estudos sobre a caracterização estrutural e a determinação da estabilidade de hemoproteínas na presença de surfactantes, por meio de várias técnicas como absorção ótica, emissão de fluorescência, CD (Dicroísmo Circular) e espalhamento de luz podem trazer informações sobre esta classe de proteínas, principalmente sobre o mecanismo de oxidação, dissociação e desnaturação. Desta forma, no presente projeto de pesquisa objetivou realizar a caraterização biofísica da hemoglobina extraída de Amynthas gracilis (HbAg) na presença de surfactantes iônicos (SDS e CTAC) nos valores de pH 5,0 e 7,0. Os resultados nos mostram que ambos os surfactantes são capazes de interagir fortemente com a HbAg, sendo que o pH do meio influência diretamente na intensidade da interação proteína-surfactante. O SDS em pH 5,0... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hemoglobins are a group of proteins that play a vital role in organisms. Their intrinsic properties, as well as their structure-activity relationship, involve phenomena such as cooperativity and affinity for specific ligands, such as oxygen, which are associated with a variety of processes that make life possible. Hemoproteins, especially hemoglobins of annelids have been studied by different research groups, due to their high oligomeric stability, resistance to oxidation, high cooperativity and affinity for specific ligands, presenting a high potential in biotechnological applications, for example, a blood substitute. Studies on the structural characterization and determination of hemoprotein stability in the presence of surfactants by optical absorption, fluorescence emission, CD and light scattering can bring information about this class of proteins, mainly on the mechanism of dissociation and denaturation. Thus, in the present master's project the main objective was to perform biophysics characterization studies, with the hemoglobin extracted from the annelid of Amynthas gracilis (HbAg) in the presence of ionic surfactants (SDS and CTAC) at pH values 5,0 and 7,0. The results show that both surfactants are capable of interacting strongly with HbAg, and the pH of the medium directly influences the intensity of the protein-surfactant interaction. SDS at pH 5.0 strongly interacts with HbAg forming precipitates of protein-surfactant complex, can be observed with low concentrations of SDS (0.01 - 0.2 mmolL -1). While for CTAC a strong interaction between surfactant and HbAg occurs at pH 7.0 in a concentration range of 0.01-0.07 mmolL-1. The formation of aggregates in these systems probably occurs as a function of the isoelectric point (pI) of HbAg being acid (6.0 ± 3), as well as that of other extracellular Hb, as a result of a strong electrostatic interaction. This study showed that SDS and CTAC promote... / Mestre

The HbS gene had a limited number of origins during history, and these can be defined by the haplotype (a set of DNA polymorphisms inherited together) of the associated β-globin gene. Five major haplotypes have been identified, and associated with different ethnic groups. These are the Arab Indian haplotype, the Benin haplotype, the Cameroonian haplotype, the Central African Republic (CAR) or Bantu haplotype, and the Senegal haplotype. The polymorphisms defining these haplotypes are associated with fetal hemoglobin, the major modifier of sickle cell disease phenotype and severity. The Arab Indian haplotype, in particular, is associated with unusually high HbF levels (20%), and a significantly less severe clinical presentation. We found a novel (C>T) SNP -68 bp 5' to HBD in this region, expressed in patients with the Arab Indian haplotype, but not sickle cell disease patients expressing other β-globin cluster haplotypes. There is evidence that this -68 (C>T) polymorphism may play a functional role in the hemoglobin expression of these patients, and its effect on globin levels and disease severity is the long-term interest of this study. A previous reporter assay in K562 cells determined that the -68 SNP was associated with decreased δ-globin gene expression. This study aims to clone the HBD region of a patient positive for this SNP into a lentiviral firefly luciferase reporter vector, for use in more physiologically accurate CD34+ erythropoietic progenitor cells. If the mutations in these β-globin gene haplotypes, such as the HBD mutation described in this study, are responsible for the protective effects seen in patients, perhaps some of these genetic locations can serve as targets for therapeutics in sickle cell disease or other blood disorders.