sh.sePublikasjoner
Endre søk
Begrens søket
3456789 251 - 300 of 824
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • harvard-anglia-ruskin-university
  • apa-old-doi-prefix.csl
  • sodertorns-hogskola-harvard.csl
  • sodertorns-hogskola-oxford.csl
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 251.
    Grivas, Spiros
    et al.
    Södertörns högskola, Avdelning Naturvetenskap. Karolinska Institute / SLU.
    Schuisky, P
    SLU.
    Synthesis of imidazonaphthyridines and -quinolines1998Inngår i: Heterocycles, ISSN 0385-5414, E-ISSN 1881-0942, Vol. 48, nr 8, s. 1575-1580Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four 2-amino-3-methylimidazo[4,5-b][1,x]naphthyridines, x = 5-8 (6-9) have been obtained from aromatic aldehydes (11-14) and 2-amino-1-methyl-2-imidazolin-5-one (15) in one step. The N-1 - and N-3 -methyl isomers of 2-aminoimidazo-[4,5-b]quinoline (5 and 10) were prepared from 2-nitrobenzaldehyde via the isolated E-isomers of imidazolin-5-one (17) and imidazolin-4-one (20).

  • 252.
    Grube, Martin
    et al.
    Graz university, Austria.
    Gutmann, B.
    Graz university, Austria.
    Arup, Ulf
    Graz university, Austria.
    Rios, A. de los
    Graz university, Austria.
    Mattsson, Jan-Eric
    Uppsala university.
    Wedin, Mats
    Natural History Museum, London.
    An exceptional group I intron-like insertion in SSU rDNA of lichen mycobionts1999Inngår i: Current Genetics, ISSN 0172-8083, E-ISSN 1432-0983, Vol. 35, s. 536-541Artikkel i tidsskrift (Fagfellevurdert)
  • 253. Guduru, Shiva Krishna Reddy
    et al.
    Chamakuri, Srinivas
    Chandrasekar, Gayathri
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik.
    Kitambi, Satish Srinivas
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    Arya, Prabhat
    Tetrahydroquinoline-Derived Macrocyclic Toolbox: The Discovery of Antiangiogenesis Agents in Zebrafish Assay2013Inngår i: ACS Medicinal Chemistry Letters, ISSN 1948-5875, E-ISSN 1948-5875, Vol. 4, nr 7, s. 666-670Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel approach to incorporate the macrocyclic rings onto the privileged substructure, i.e. tetrahydroquinoline scaffold, is developed. The presence of an amino acid-derived moiety in the macrocyclic skeleton provides an opportunity to modulate the nature of the chiral side chain. Further, evaluation in a zebrafish screen identified three active small molecules (2.5b, 3.2d, and 4.2) as antiangiogenesis agents at 2.5 mu M.

  • 254.
    Gulin, Sofia
    et al.
    Södertörns högskola, Avdelning Naturvetenskap.
    Kussak, A
    Jansson, P E
    Widmalm, G
    Structural studies of S-7, another exocellular polysaccharide containing 2-deoxy-arabino-hexuronic acid2001Inngår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 331, nr 3, s. 285-290Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The exocellular polysaccharide S-7, a heteropolysaccharide from Azotobacter indicus var, myxogenes has been studied using methylation analysis, Smith degradation, partial acid hydrolysis, NMR spectroscopy and mass spectrometry as the principal methods. It is concluded that the repeating unit has the following structure: -->4)-beta -D-Glcp-(1 -->4)-alpha -L-Rhap-(1 -->3)-beta -D-2-deoxy-arabino-HexpA-(1 --> 6 up arrow 1 beta -D-Glcp-(1 -->6)-beta -D-Glcp The absolute configuration of the deoxyhexuronic acid was deduced from H-1 NMR chemical shifts and is most likely D. Approximately two O-acetyl groups per repeating unit are present, one of which is presumably on the Rha residue. The structure bears great resemblance to another polysaccharide, recently studied, produced by Sphingomonas paucimobilis I-886.

  • 255.
    Gullström, Martin
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Dahl, Martin
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Lindén, Olof
    Vorhies, Francis
    Forsberg, Sara
    Stockholm University, Sweden .
    Ismail, Rashid O.
    Stockholm University, Sweden; University of Dar es Salaam, Tanzania.
    Björk, Mats
    Stockholm University, Sweden.
    Coastal blue carbon stocks in Tanzania and Mozambique: Support for climate adaptation and mitigation actions2021Rapport (Annet vitenskapelig)
  • 256. Gupta, M P
    et al.
    Solis, P N
    Calderon, A I
    Guionneau-Sinclair, Francoise
    Södertörns högskola, Institutionen för livsvetenskaper.
    Correa, M
    Galdames, C
    Guerra, C
    Espinosa, A
    Alvenda, G I
    Robles, G
    Ocampo, R
    Medical ethnobotany of the Teribes of Bocas del Toro, Panama2005Inngår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 96, nr 3, s. 389-401Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ethnomedical uses of 108 medicinal plant species, belonging to 52 families, 89 genera, used by the Teribe Amerindians of Bocas del Toro Province in Panama. along with their socio-cultural practices are reported here. The methods of administration of the herbal remedies, the plant parts used, their families and local names are also documented. The recorded medicinal plants were used mainly for fever, various type of pain and inflammation. The potential value of 26 plants and their traditional uses was elucidated through literature search.

  • 257. Güntert, P
    et al.
    Berndt, Kurt D
    Eidgenössische Technische Hochschule-Hönggerberg, Zürich, Switzerland.
    Wüthrich, K
    The Program Asno for Computer-Supported Collection of Noe Upper Distance Constraints as Input for Protein-Structure Determination1993Inngår i: Journal of Biomolecular NMR, ISSN 0925-2738, E-ISSN 1573-5001, Vol. 3, nr 5, s. 601-606Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new program, ASNO ('ASsign NOes'), for computer-supported NOE cross-peak assignments is described. ASNO is used for structure refinement in several rounds of NOESY cross-peak assignments and 3D structure calculations, where the preliminary structures are used as a reference to resolve ambiguities in NOE assignments which are otherwise based on the chemical shifts available from the sequence-specific resonance assignments. The practical use of ASNO for proteins is illustrated with the structure determination of Dendrotoxin K from Dendroaspis polylepis polylepis.

  • 258. Haas, S A
    et al.
    Hild, M
    Wright, Anthony P H
    Södertörns högskola, Avdelning Naturvetenskap. Karolinska Institutet.
    Hain, T
    Talibi, D
    Vingron, M
    Genome-scale design of PCR primers and long oligomers for DNA microarrays2003Inngår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 31, nr 19, s. 5576-5581Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    During the last years, the demand for custom-made cDNA chips/arrays as well as whole genome chips is increasing rapidly. The efficient selection of gene-specific primers/oligomers is of the utmost importance for the successful production of such chips. We developed GenomePRIDE, a highly flexible and scalable software for designing primers/oligomers for large-scale projects. The program is able to generate either long oligomers (40-70 bases), or PCR primers for the amplification of gene-specific DNA fragments of user-defined length. Additionally, primers can be designed in-frame in order to facilitate large-scale cloning into expression vectors. Furthermore, GenomePRIDE can be adapted to specific applications such as the generation of genomic amplicon arrays or the design of fragments specific for alternative splice isoforms. We tested the performance of GenomePRIDE on the entire genomes of Listeria monocytogenes (1584 gene-specific PCRs, 48 long oligomers) as well as of eukaryotes such as Schizosaccharomyces pombe (5006 gene-specific PCRs), and Drosophila melanogaster (21306 gene-specific PCRs). With its computing speed of 1000 primer pairs per hour and a PCR amplification success of 99%, GenomePRIDE represents an extremely cost- and time-effective program.

  • 259.
    Hallgren, Stefan
    Södertörns högskola, Institutionen för livsvetenskaper, Biologi. Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap.
    Brain aromatase in the guppy, Poecilia reticulata: distribution, control and role in behaviour2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Download (jpg)
    presentationsbild
  • 260.
    Hallgren, Stefan
    Södertörns högskola, Institutionen för livsvetenskaper.
    Neuroestrogen and male reproductive behaviour in the guppy2006Licentiatavhandling, monografi (Annet vitenskapelig)
  • 261.
    Hallgren, Stefan
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper.
    Kitambi, Satish Srinivas
    Karolinska Institutet.
    Cloning, sequencing and In situ localisation of guppy brain aromatase, cyp19bManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Oestrogens are biosynthesised by cytochrome p450-aromatase (Cyp19). Brain oestrogens serve several important functions of which nerve protection, cell proliferation, nerve development and behaviour control are a few. Teleost brain aromatase activity is exceptionally high (between 100-1000 times) compared to mammals and birds. We have successfully cloned and sequenced a 950 bp long partial fragment of the guppy CYP19B gene (PrCyp19b) derived from adult brain mRNA. Sequence alignment of translated amino acid sequence shows PrCYP19b having high sequence similarity to teleost brain aromatase. Anatomical distribution of PrCYP19b expression in adult guppy brains was studied using in situ-hybridisation with an antisense riboprobe synthesised from the cloned PrCYP19b gene. Expression of brain aromatase appeared at ventricular surfaces of the ventral telencephalic zones and the pre-optic area, in the hypothalamus, the pituitary gland, optic tectum and the cerebellum. This pattern is similar to previously reported distribution of brain aromatase in other teleosts. Measurement of brain aromatase activity in telencephalon, mesencephalon/diencephalon and rhombencephalon revealed female guppies producing the most oestrogens in mesencephalon/diencephalon, whereas males produces the most oestrogens in both telencephalon and mesencephalon/diencephalon. This indicates that brain oestrogen production is sexually dimorphic in the guppy and may serve different functions in the two genders.

  • 262.
    Hallgren, Stefan
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap. Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Olsén, K Håkan
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap. Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Effects on Guppy Brain Aromatase Activity Following Short-Term Steroid and 4-Nonylphenol Exposures2010Inngår i: Environmental Toxicology, ISSN 1520-4081, E-ISSN 1522-7278, Vol. 25, nr 3, s. 261-271Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brain estrogen production, performed by the enzyme aromatase, can be disrupted/affected in teleost fish exposed to endocrine disruptors found in polluted aquatic environments. The guppy (Poecilia reticulata) was previously studied and confirmed to suffer negative effects on reproductive behaviors following inhibition of the brain aromatase reaction. Here adult guppies (Poecilia reticulata) of both genders were subjected to known endocrine disruptors: the androgen androstenedione (A), the synthetic estrogen 17 alpha-ethinylestradiol (EE2), and the estrogenic surfactant 4-nonylphenol (NP), at high (50 mu g/L) and at environmentally relevant concentrations (10 ng/L EE2, 5 mu g/L NP, and 0.7 mu g/L A) for 2 weeks followed by measurements of brain aromatase activity (bAA). In the adult males, bAA was stimulated by A and EE2 at 50 mu g/L. Female activity was also stimulated by the higher estrogenic treatment. At environmentally relevant concentrations only the EE2 treatment affected bAA, and only in males. The alkylphenolic substance NP produced no effect in either of the experiments, not on males nor females. The results indicate that short-term steroid treatments have stimulatory effects on guppy brain aromatase even at concentrations that can be found in the environment. We thus suggest bAA of adult guppies to be a suitable bioindicator of endocrine disruptors.

  • 263.
    Hallgren, Stefan
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper.
    Olsén, K Håkan
    Södertörns högskola, Institutionen för livsvetenskaper.
    Impacts of synthetic oestrogen and antioestrogen treatments on courtship and mating behaviours in male guppies (Poecilia reticulata)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Understanding the neuroendocrinological mechanisms behind reproductive behaviour is fundamental when studying endocrine disruption. Neuroestrogen production is a key step in the activation of reproductive behaviours among vertebrates. The actions of estrogens are transmitted through estrogen receptors (ERs) in distinct brain nuclei. Here we report alterations in reproductive behaviours in guppy males following 55-day food treatments with the antiestrogen fulvestrant (ICI) and the synthetic oestrogen 17α-ethinylestradiol (EE2). Male courtship and mating attempts were severely reduced in EE2 treated males after both 27-30 and 41-55 days of treatment when paired with females. ICI treatment gave a significant reduction in the frequency of sigmoid display behaviour after 27-30 days of treatment, and an almost 2.5-fold increase in gonopodium thrusting after 41-55 days of treatment. ICI treated males also decreased their frequency in successful mating attempts in comparison to the control males. The neurological effects of ICI were confirmed by Real Time-PCR analysis for brain aromatase and ERα gene expression. ICI treatment suppressed aromatase expression to 64% and stimulated ERα gene expression by over 300%. These results indicate that oestrogen action via ERs may play an important role for the complete display of male courtship and mating behaviour in the guppy. The results also suggest that local steroids are involved in regulating brain aromatase expression and that the negative effects of EE2 on sexual behaviour are linked via endocrine disruption of gonadal function.

  • 264.
    Hallgren, Stefan
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap. Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Volkova, Kristina
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap.
    Reyhanian, Nasim
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap.
    Olsén, K Håkan
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap. Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Porsch Hällström, Inger
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap.
    Anxiogenic behaviour induced by 17α-ethynylestradiol in male guppies (Poecilia reticulata)2011Inngår i: Fish Physiology & Biochemistry, ISSN 0920-1742, E-ISSN 1573-5168, Vol. 37, nr 4, s. 911-918Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Behaviour studies are used in toxicology research as they are excellent tools to measure physiological end-points caused by exogenous chemicals. In mammals both reproductive and non-reproductive behaviours have been used for a long period of time, whereas in teleost fishes non-reproductive behaviours have received little attention compared to reproductive behaviours. Recent advances in measuring stress related behaviours in zebrafish have provided additional tools to understand behaviour toxicology in fish. One species with well documented reproductive behaviour disturbed by different toxicants is the guppy, which is better suited than zebrafish for reproductive behaviour studies and therefore might be a better model organism for comparative behaviour studies in fish toxicology. Here we report new applications for non-reproductive behaviours in guppy and test these behaviours on males treated with the endocrine disruptor 17α-ethynylestradiol at environmentally relevant concentrations. 17α-ethynylestradiol increased freezing and bottom-dwelling when fish were placed in a non-familiar aquarium, but did not significantly affect shoaling behaviour. These results are similar to the anxiogenic behaviours seen in rats treated perinatally with 17α-ethynylestradiol and add more concern to the impacts of endocrine disruptors on aquatic wildlife.

  • 265.
    Halltin Nijm, Nadja
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik.
    Biodiversitet i naturliga kolsänkor: sammansättning av sedimentlevande djur samt kollagring i kustnära habitat2022Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Havet har en nyckelroll när det kommer till de ökade koldioxidutsläppen som tär på miljön då den är en naturlig kolsänka. Kustnära habitat och vegeterade områden såsom sjögräsängar har visat sig vara mycket effektiva på att fånga upp organiskt kol som lagras i bottensedimenten. Kapaciteten till att lagra kol i kustnära habitat varierar beroende på faktorer som t ex växtbiomassa, sedimentets kornstorlek och artsammansättningen av djur som hjälper till att bryta ner kolet. Däremot har djursammansättningen forskats om i begränsad utsträckning. Därför har denna studie valt att undersöka sammansättningen av sedimentlevande djur i kustnära habitat och dess relation till kolinnehållet. Sedimentkärnor samlades från de utvalda kustnära habitaten (Ruppia spp., nateväxter, ålgräs, ickevegeterad mjukbotten samt torrvass och våtvass) för att artidentifiera djuren och för att räkna ut det sedimentära organiska kolinnehållet. Resultatet visade signifikanta skillnader mellan alla habitats artsammansättningar förutom mellan nateväxter och Ruppia spp., nateväxter och ålgräs samt mellan ickevegeterad mjukbotten och torrvass. Arter som förekom och bidrog mest till variationen mellan och inom habitaten var Oligochaeta, Hydrobia spp., Chironomidae, Hediste diversicolor och Macoma balthica. Det hittades inget positivt samband mellan artsammansättningen och kollagringen i de kustnära habitaten eftersom vassområdena hade en låg artrikedom men ett högt kolinnehåll, medan nateväxthabitatet som hade störst artrikedom innehöll ett lågt kolinnehåll. Istället kan andra faktorer ha bidragit mer till habitatens kollagringar. Däremot förekom ett högt antal av Chironomidae i vassbältena som innehöll ett högre organiskt kolinnehåll. Anledningen till detta beror troligen på deras förmåga att klara av syrefattiga miljöer som rådde i vassbältena, snarare än att de bidrog till kollagringen. Eftersom kustnära habitat är effektiva kolsänkor är det viktigt att detta fortsätter forskas om för en ökad förståelse för vilka faktorer som påverkar deras kolsänkekapacitet.

    Fulltekst (pdf)
    fulltext
  • 266. Hammarström, A
    et al.
    Berndt, Kurt D
    Karolinska Institutet.
    Sillard, R
    Adermann, K
    Otting, G
    Solution structure of a naturally-occurring zinc-peptide complex demonstrates that the N-terminal zinc-binding module of the Lasp-1 LIM domain is an independent folding unit1996Inngår i: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 35, nr 39, s. 12723-12732Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The three-dimensional solution structure of the 1:1 complex between the synthetic peptide ZF-1 and zinc was determined by H-1 NMR spectroscopy. The peptide, initially isolated from pig intestines, is identical in sequence to the 30 N-terminal amino acid residues of the human protein Lasp-1 belonging to the LIM domain protein family. The final set of 20 energy-refined NMR conformers has an average rmsd relative to the mean structure of 0.55 Angstrom for the backbone atoms of residues 3-30, Calculations without zinc atom constraints unambiguously identified Cys 5, Cys 8, His 26, and Cys 29 as the zinc-coordinating residues. LIM domains consist of two sequential zinc-binding modules and the NMR structure of the ZF-1(-)zinc complex is the first example of a structure of an isolated module. Comparison with the known structures of the N-terminal zinc-binding modules of both the second LIM domain of chicken CRP and rat GRIP with which ZF-1 shares 50% and 43% sequence identity, respectively, supports the notion that the zinc-binding modules of the LIM domain have a conserved structural motif and identifies local regions of structural diversity. The similarities include conserved zinc-coordinating residues, a rubredoxin knuckle involving Cys 5 and Cys 8, and the coordination of the zinc ion by histidine N-delta in contrast to the more usual coordination by N-epsilon observed for other zinc-finger domains, The present structure determination of the ZF-1(-)zinc complex establishes the N-terminal half of a LIM domain as an independent folding unit. The structural similarities of N- and C-terminal zinc-binding modules of the LIM domains, despite limited sequence identity, lead to the proposal of a single zinc-binding motif in LIM domains. The coordinates are available from the Brookhaven protein data bank, entry 1ZFO.

  • 267. Hamsten, C.
    et al.
    Starkhammar, M.
    Tran, T. A. T.
    Johansson, Magnus
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi. Örebro University.
    Bengtsson, U.
    Ahlen, G.
    Sallberg, M.
    Gronlund, H.
    van Hage, M.
    Identification of galactose-alpha-1,3-galactose in the gastrointestinal tract of the tick Ixode sricinus; possible relationship with red meat allergy2013Inngår i: Allergy. European Journal of Allergy and Clinical Immunology, ISSN 0105-4538, E-ISSN 1398-9995, Vol. 68, nr 4, s. 549-552Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Patients with IgE antibodies against the carbohydrate epitope galactose--1,3-galactose (-Gal) have reported severe allergic reactions after consumption of red meat. Investigations have revealed associations between IgE to -Gal and tick bites. We provide the first direct evidence that -Gal is present within ticks thus potentially explaining the relationship between tick exposure and sensitization to -Gal, with development of red meat allergy as a secondary phenomena. Serum from Swedish patients with delayed severe reactions to red meat was included in the study. A dose-dependent inhibition of IgE responses to -Gal by the tick Ixodesricinus is demonstrated. Furthermore, using cryostat-cut sections of I.ricinus, we show that both a monoclonal and a polyclonal antibody against -Gal stains the gastrointestinal tract of the tick. The same pattern is seen when staining with patient sera IgE positive to -Gal. These results confirm that the -Gal epitope is present in I.ricinus and imply host exposure to -Gal during a tick bite. This provides further evidence that tick bites are associated with IgE responses to -Gal and red meat allergy.

  • 268. Hanson, K
    et al.
    Lönn, Mikael
    Effekter av hyggesbruk och habitat-egenskaper pa den demografiska strukturen hos populationer av glesgroe Glyceria lithuanica1999Inngår i: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 93, nr 5/6, s. 249-256Artikkel i tidsskrift (Annet vitenskapelig)
  • 269. Hao, Limin
    et al.
    Aspöck, Gudrun
    Bürglin, Thomas R
    Södertörns högskola, Institutionen för livsvetenskaper. Karolinska Institute.
    The hedgehog-related gene wrt-5 is essential for hypodermal development in Caenorhabditis elegans2006Inngår i: Developmental Biology, ISSN 0012-1606, E-ISSN 1095-564X, Vol. 290, nr 2, s. 323-336Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Caenorhabditis elegans genome encodes a series of hedgehog-related genes, which are thought to have evolved and diverged from an ancestral Hh gene. They are classified into several families based on their N-terminal domains. Here, we analyze the expression and function of a member of the warthog gene family, wrt-5, that lacks the Hint/Hog domain. wrt-5 is expressed in seam cells, the pharynx, pharyngeal-intestinal valve cells, neurons, neuronal support cells, the excretory cell, and the reproductive system. WRT-5 protein is secreted into the extracelluar space during embryogenesis. Furthermore, during larval development, WRT-5 protein is secreted into the pharyngeal lumen and the pharyngeal expression changes in a cyclical manner in phase with the molting cycle. Deletion mutations in wrt-5 cause embryonic lethality, which are temperature sensitive and more severe at 15 degrees C than at 25 degrees C. Animals that hatch exhibit variable abnormal morphology, for example, bagging worms, blistering, molting defects, or Roller phenotypes. We examined hypodermal cell junctions using the AJM-1: :GFP marker in the wrt-5 mutant background and observed cell boundary abnormalities in the arrested embryos. AJM-1: :GFP protein is also misplaced in pharyngeal muscle cells in the absence of WRT-5. In conclusion, we show that wrt-5 is an essential gene that - despite its lack of a Hint domain - has multiple functions in C. elegans and is implicated in cell shape integrity.

  • 270. Hao, Limin
    et al.
    Johnsen, Robert
    Lauter, Gilbert
    Södertörns högskola, Institutionen för livsvetenskaper. Karolinska Institute.
    Baillie, David
    Bürglin, Thomas R.
    Södertörns högskola, Institutionen för livsvetenskaper. Karolinska Institute.
    Comprehensive analysis of gene expression patterns of hedgehog-related genes2006Inngår i: BMC Genomics, E-ISSN 1471-2164, Vol. 7, s. 280-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The Caenorhabditis elegans genome encodes ten proteins that share sequence similarity with the Hedgehog signaling molecule through their C-terminal autoprocessing Hint/Hog domain. These proteins contain novel N-terminal domains, and C. elegans encodes dozens of additional proteins containing only these N-terminal domains. These gene families are called warthog, groundhog, ground-like and quahog, collectively called hedgehog (hh)-related genes. Previously, the expression pattern of seventeen genes was examined, which showed that they are primarily expressed in the ectoderm. Results: With the completion of the C. elegans genome sequence in November 2002, we reexamined and identified 61 hh-related ORFs. Further, we identified 49 hh-related ORFs in C. briggsae. ORF analysis revealed that 30% of the genes still had errors in their predictions and we improved these predictions here. We performed a comprehensive expression analysis using GFP fusions of the putative intergenic regulatory sequence with one or two transgenic lines for most genes. The hh-related genes are expressed in one or a few of the following tissues: hypodermis, seam cells, excretory duct and pore cells, vulval epithelial cells, rectal epithelial cells, pharyngeal muscle or marginal cells, arcade cells, support cells of sensory organs, and neuronal cells. Using time-lapse recordings, we discovered that some hh-related genes are expressed in a cyclical fashion in phase with molting during larval development. We also generated several translational GFP fusions, but they did not show any subcellular localization. In addition, we also studied the expression patterns of two genes with similarity to Drosophila frizzled, T23D8.1 and F27E11.3A, and the ortholog of the Drosophila gene dally-like, gpn-1, which is a heparan sulfate proteoglycan. The two frizzled homologs are expressed in a few neurons in the head, and gpn-1 is expressed in the pharynx. Finally, we compare the efficacy of our GFP expression effort with EST, OST and SAGE data. Conclusion: No bona-fide Hh signaling pathway is present in C. elegans. Given that the hh-related gene products have a predicted signal peptide for secretion, it is possible that they constitute components of the extracellular matrix (ECM). They might be associated with the cuticle or be present in soluble form in the body cavity. They might interact with the Patched or the Patched-related proteins in a manner similar to the interaction of Hedgehog with its receptor Patched.

  • 271. Hao, Limin
    et al.
    Mukherjee, Krishanu
    Liegeois, Samuel
    Baillie, David
    Labouesse, Michel
    Bürglin, Thomas R.
    Södertörns högskola, Institutionen för livsvetenskaper. Karolinska institutet.
    The hedgehog-related gene qua-1 is required for molting in Caenorhabditis elegans2006Inngår i: Developmental Dynamics, ISSN 1058-8388, E-ISSN 1097-0177, Vol. 235, nr 6, s. 1469-1481Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Caenorhabditis elegans genome encodes ten proteins that share similarity with Hedgehog through the C-terminal Hint/Hog domain. While most genes are members of larger gene families, qua-1 is a single copy gene. Here we show that orthologs of qua-1 exist in many nematodes, including Brugia malayi, which shared a common ancestor with C. elegans about 300 million years ago. The QUA-1 proteins contain an N-terminal domain, the Qua domain, that is highly conserved, but whose molecular function is not known. We have studied the expression pattern of qua-1 in C. elegans using a qua-1::GFP transcriptional fusion. qua-1 is mainly expressed in hyp1 to hyp11 hypodermal cells, but not in seam cells. It is also expressed in intestinal and rectal cells, sensilla support cells, and the P cell lineage in L1. The expression of qua-1::GFP undergoes cyclical changes during development in phase with the molting cycle. It accumulates prior to molting and disappears between molts. Disruption of the qua-1 gene function through an internal deletion that causes a frame shift with premature stop in the middle of the gene results in strong lethality. The animals arrest in the early larval stages due to defects in molting. Electron microscopy reveals double cuticles due to defective ecdysis, but no obvious defects are seen in the hypodermis. Qua domain-only::GFP and full-length QUA-1::GFP fusion constructs are secreted and associated with the overlying cuticle, but only QUA-1::GFP rescues the mutant phenotype. Our results suggest that both the Hint/Hog domain and Qua domain are critically required for the function of QUA-1.

  • 272.
    Havervall, Carolina
    Södertörns högskola, Institutionen för livsvetenskaper.
    CXCL13: A Prognostic Marker in Multiple Sclerosis2010Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In the demyelinating autoimmune disease multiple sclerosis (MS) there is a great need for validated prognostic biomarkers that can give information about both prognosis and disease course. So far only clinical parameters have been shown to predict future outcome. CXCL13 is a potent B cell chemoattractant that has been suggested to be a potential biomarker candidate. The aim of this study was to investigate the usefulness of CXCL13 as a prognostic biomarker for MS.

    Clinical, paraclinical, laboratory and MRI data about a large group of MS patients and controls were collected. CXCL13 levels in cerebrospinal fluid (CSF) samples from these patients were determined by standard enzymelinked immunosorbent assay (ELISA).

    In general CXCL13 were increased in CSF in MS, especially in relapsing-remitting MS during relapses, i.e. with ongoing inflammations in the central nervous system. CXCL13 is a good candidate prognostic marker for MS, since newly diagnosed MS with high CXCL13 levels showed worsened disease course within five years. Most importantly, MS conversion occurred in higher rate in possible MS patients with high concentrations of CXCL13 in CSF, and in a shorter time point. This observation may support an early treatment decision in these patients.

    In conclusion, this study provides support for an association between CXCL13 levels in the CSF and later development of disease severity in MS.

    Fulltekst (pdf)
    Carolina Havervall_CXCL13: A Prognostic Marker in Multiple Sclerosis
  • 273.
    Hedlund, Eva-Maria
    Södertörns högskola, Institutionen för livsvetenskaper.
    Molecular mechanisms of angiogenic synergism between Fibroblast Growth Factor-2 and Platelet Derived Growth Factor-BB2006Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Fulltekst (pdf)
    FULLTEXT01
  • 274.
    Hedlund, Johanna S. U.
    Södertörns högskola, Institutionen för livsvetenskaper.
    Living with males: benefits and costs to females of resident males in Colobus vellerosus2009Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Only in primates is permanent male-female association the most widespread social structure of all. The continuous presence of resident males in the social group can have significant impacts on female fitness, both in forms of costs and benefits. In this study I investigate particular short-term benefits and costs of resident males to females in a population of ursine colobus (Colobus vellerosus). I hypothesise that for females permanent association with males result in certain benefits and certain costs, exceeding those provided or imposed by other females. The results indicate that female derive greater benefits from males than from females during intergroup encounters and in the form of vigilance since males were the main participants in intergroup encounter and were more vigilant than females. I could not confirm any type of behaviour employed by resident males that is costly to females. However, the rarity and subtleness of some costly male behaviours imply that more data is needed before making a conclusion on their absence or occurrence in this population and I purpose that herding behaviour could occur at my study site. Moreover, multi-male groups (MM-groups) showed higher rates of vigilance than single-male groups (SM-groups) and had a tendency to experiencing fewer intergroup encounters than SM-groups. I interpret the former as a result of the demanding social conditions in the MM-groups. The latter indicate that females may benefit from MM-group living through a decrease in intergroup encounters.

    Fulltekst (pdf)
    FULLTEXT01
  • 275.
    Heidmarsson, Starri
    et al.
    Uppsala universitet.
    Mattsson, Jan-Eric
    Uppsala universitet.
    Moberg, Roland
    Uppsala universitet.
    Nordin, Anders
    Uppsala universitet.
    Santesson, Rolf
    Uppsala universitet.
    Tibell, Leif
    Uppsala universitet.
    Classification of lichen photomorphs1997Inngår i: Taxon, ISSN 0040-0262, E-ISSN 1996-8175, nr 46, s. 519-520Artikkel i tidsskrift (Fagfellevurdert)
  • 276.
    Hellblom, Frida
    et al.
    Södertörns högskola, Avdelning Naturvetenskap.
    Axelsson, Lennart
    External HCO3- dehydration maintained by acid zones in the plasma membrane is an important component of the photosynthetic carbon uptake in Ruppia cirrhosa2003Inngår i: Photosynthesis Research, ISSN 0166-8595, E-ISSN 1573-5079, Vol. 77, nr 2-3, s. 173-181Artikkel i tidsskrift (Fagfellevurdert)
  • 277.
    Hellström, Gustav
    et al.
    Swedish University of Agricultural Sciences.
    Brodin, Tomas
    Swedish University of Agricultural Sciences.
    Jonsson, Micael
    Umeå University.
    Olsén, K. Håkan
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Leander, Johan
    Umeå University.
    Fahlman, Johan
    Umeå University.
    Fick, Jerker
    Umeå University.
    Klaminder, Jonatan
    Umeå University.
    Environmentally relevant concentrations of the common anxiolytic pharmaceutical oxazepam do not have acute effect on spawning behavior in mature male Atlantic salmon (Salmo salar) parr2020Inngår i: Journal of Applied Ichthyology, ISSN 0175-8659, E-ISSN 1439-0426, Vol. 36, nr 1, s. 105-112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Low concentrations of psychiatric drugs are commonly found in surface waters around the world, and their ability to alter behaviors in aquatic fauna has raised concerns about ecological effects. One critical effect that contamination can have in aquatic systems is modifications of reproductive behaviors. In this study, we hypothesized that oxazepam, a common anxiolytic drug and aquatic contaminant previously shown to induce anti-anxiety behavior in salmonids, also affects the reproductive behavior of Atlantic salmon (Salmo salar). To test this hypothesis, small sexually mature Atlantic salmon males (mature parr) were exposed to concentrations of oxazepam comparable to that of effluent water (1.9 mu g/L). After 5 days of exposure, their reproductive behavior was compared with that of unexposed control individuals. Behavior was monitored in a large-scale flume aquarium that also contained a large male and a female to mimic natural spawning conditions for Atlantic salmon. Three behaviors were quantified for the mature parr; (a) amount of courting behavior towards female, (b) proximity to female, and (c) amount of attacks received from the large male. In contrast to our hypothesis, no difference in either courting behavior, proximity to female, or received aggression could be found between exposed and control male parr. Hence, our results indicate that there is no acute effect of the highest levels of oxazepam concentration reported for urban environments on spawning behavior of mature male parr, although chronic effects could not be ruled out.

  • 278.
    Hellström, Gustav
    et al.
    SLU, Umeå.
    Prestegaard, Tore
    SLU, Uppsala .
    Dannewitz, Johan
    SLU, Uppsala.
    Olsén, Håkan
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap. Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi.
    Sperm from pheromone primed brown trout (Salmo trutta L.) produce more larvae2013Inngår i: Fish Physiology & Biochemistry, ISSN 0920-1742, E-ISSN 1573-5168, Vol. 39, nr 3, s. 471-478Artikkel i tidsskrift (Fagfellevurdert)
    Fulltekst (pdf)
    fulltext
  • 279.
    Hench, Jürgen
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    Henriksson, Johan
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Instiututet.
    Abou-Zied, Akram M
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    Lüppert, Martin
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Instiutetet.
    Dethlefsen, Johan
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    Mukherjee, Krishanu
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Intitutet.
    Tong, Yong Guang
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Intitutet.
    Tang, Lois
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    Gangishetti, Umesh
    Karolinska Institutet.
    Baillie, David L
    Simon Fraser University, Burnaby, British Columbia, Canada.
    Bürglin, Thomas R
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institutet.
    The Homeobox Genes of Caenorhabditis elegans and Insights into Their Spatio-Temporal Expression Dynamics during Embryogenesis2015Inngår i: PLOS ONE, E-ISSN 1932-6203, Vol. 10, nr 5, artikkel-id e0126947Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Homeobox genes play crucial roles for the development of multicellular eukaryotes. We have generated a revised list of all homeobox genes for Caenorhabditis elegans and provide a nomenclature for the previously unnamed ones. We show that, out of 103 homeobox genes, 70 are co-orthologous to human homeobox genes. 14 are highly divergent, lacking an obvious ortholog even in other Caenorhabditis species. One of these homeobox genes encodes 12 homeodomains, while three other highly divergent homeobox genes encode a novel type of double homeodomain, termed HOCHOB. To understand how transcription factors regulate cell fate during development, precise spatio-temporal expression data need to be obtained. Using a new imaging framework that we developed, Endrov, we have generated spatio-temporal expression profiles during embryogenesis of over 60 homeobox genes, as well as a number of other developmental control genes using GFP reporters. We used dynamic feedback during recording to automatically adjust the camera exposure time in order to increase the dynamic range beyond the limitations of the camera. We have applied the new framework to examine homeobox gene expression patterns and provide an analysis of these patterns. The methods we developed to analyze and quantify expression data are not only suitable for C. elegans, but can be applied to other model systems or even to tissue culture systems.

  • 280.
    Hench, Jürgen
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper.
    Henriksson, Johan
    Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi.
    Lüppert, Martin
    Södertörns högskola, Institutionen för livsvetenskaper.
    Bürglin, Thomas R.
    Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi.
    Spatio-temporal reference model of Caenorhabditis elegans embryogenesis with cell contact maps2009Inngår i: Developmental Biology, ISSN 0012-1606, E-ISSN 1095-564X, Vol. 333, nr 1, s. 1-13Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The nematode Caenorhabditis elegans has been used as a model for developmental biology for decades. Still, the few publicly available spatio-temporal (4D) data sets have conflicting information regarding variability of cell positions and are not well-suited for a standard 4D embryonic model, due to compression. We have recorded six uncompressed embryos, and determined their lineage and 4D coordinates, including nuclear radii, until the end of gastrulation. We find a remarkable degree of stability in the cell positions, as well as little rotational movement, which allowed us to combine the data into a single reference model of C. elegans embryogenesis. Using Voronoi decomposition we generated the list of all predicted cell contacts during early embryogenesis and calculated these contacts up to the similar to 150 cell stage, and find that about 1500 contacts last 2.5 min or longer. The cell contact map allows for comparison of multiple 4D data sets, e. g., mutants or related species, at the cellular level. A comparison of our uncompressed 4D model with a compressed embryo shows that up to 40% of the cell contacts can be different. To visualize the 4D model interactively we developed a software utility. Our model provides an anatomical resource and can serve as foundation to display 4D expression data, a basis for developmental systems biology.

  • 281.
    Henriksson, Johan
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institute.
    Hench, Jürgen
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institute.
    Tong, Yong Guang
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institute.
    Johansson, Arvid
    Johansson, David
    Bürglin, Thomas R.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik. Karolinska Institute.
    Endrov: an integrated platform for image analysis2013Inngår i: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 10, nr 6, s. 454-456Artikkel i tidsskrift (Fagfellevurdert)
  • 282.
    Henriksson, Oskar
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi. Stockholms universitet.
    Genetic connectivity of fish in the Western Indian Ocean2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    An almost unbroken fringing reef runs along the east coast of Africa, the lagoon inside the reef is the foundation of almost all artisanal fisheries. It is a low-tech fishery conducted by many people. Some areas can have up to 19 fishermen per square kilometer. High fishing pressures, coupled with declining fish stocks has led to changes in mean size and reproductive age of many exploited species. There is a vital and urgent need for scientifically based management systems, including the utilization of genetic information to guide management practices.

    This thesis aims to investigate the presence of genetic structures in the western Indian Ocean. In order to do that we first investigated the historical patterns of connectivity throughout the region (paper I). In papers II and III we focused on local scale connectivity in Kenya and Tanzania and finally in paper IV we investigate the large-scale contemporary gene flow throughout the Western Indian Ocean. In paper III we also investigate the temporal genetic variation at one site and compare it to the small-scale genetic variation along a stretch of the Kenyan coastline. Some overall conclusions that can be drawn from my body of work are: there are genetic structures present in the western Indian Ocean even though the apparent lack of physical barriers. Major oceanic currents aid evolutionary dispersal patterns. A single geographic site need not be genetically homogenous or temporally stable. Island sites are genetically more homogenous than mainland sites.

    In conclusion, there are clear and distinct genetic structures present especially in Siganus sutor, the most targeted fish for the artisanal fishery in East Africa.

  • 283.
    Henriksson, Oskar
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi. Stockholms universitet.
    Grahn, Mats
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi.
    Contrasting population genetic structure of Siganus sutor between mainland coastal and oceanic island populationsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Studies on genetic connectivity are important for the management of fisheries. In this study we used AFLP to investigate population structure of the endemic Spinefoot shoemaker, Siganus sutor, from 6 countries, Kenya, Tanzania, Comoros, Seychelles and Mauritius in the Western Indian Ocean. We collected 506 samples from 20 fish landing sites, 171 variable loci were used in the statistical analysis. Global FST was significant and showed a pattern of isolation by distance, mostly influenced by remote oceanic islands. In a previous study we have described the temporal variation of Siganus sutor to be about 1/5 of the global variation, and by applying a 1/5 of the global variation cut of value for the pair-wise comparisons we were able to account some of the pair- wise genetic variation as temporal fluctuations. A STRUCTURE analysis was also preformed that corroborates the pair-wise FST comparisons. Overall these results show that S. sutor is genetically diverse and subdivided throughout the region, but also that the current management regime might not be optimal. 

  • 284.
    Henriksson, Oskar
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi. Stockholms universitet.
    Larsson, Josefine
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Grahn, Mats
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi.
    Temporal genetic variability of landed Siganus sutor reveals a mixed stock fishery in coastal KenyaManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Artisanal fisheries in Kenya have been in decline since the 1980’s and are currently managed by gear restriction and no take zones. The fishery is a mixed species fishery but the Shoemaker spinefoot (Siganus sutor) comprise a large portion of the total catches. The sustainable use of these resources is dependent on informed assessment and management of the harvested species. In Kenya there is a lack of critical information about landings, fish stock productivity and genetic stock structure, and there is no knowledge of populations size or genetic variation of S. sutor. In this study we used the molecular marker, AFLP to investigate the genetic variation within and between sites of S. sutor landed along the 200 km coast of Kenya. We compared the spatial genetic variation among sites with the within site temporal genetic variation from a single site, adjacent to a number of spawning aggregations. Our results show that the there is genetic variation among the sites (spatial variation) and that the temporal genetic variation with in a six week period was about 1/5 of the spatial genetic variation. We believe these findings to be an important aspect to considered for both future scientific research as well as management.

  • 285.
    Henriksson, Oskar
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Mwandya, Augustine
    Sokoine University of Agriculture.
    Gullström, Martin
    Stockholm University.
    Thorberg, Marika
    Södertörns högskola, Institutionen för livsvetenskaper.
    Grahn, Mats
    Södertörns högskola, Institutionen för livsvetenskaper, Biologi.
    Genetic Identification and Population Structure of Juvenile Mullet (Mugilidae) Collected for Aquaculture in East Africa2012Inngår i: Western Indian Ocean Journal of Marine Science, ISSN 0856-860X, E-ISSN 2683-6416, Vol. 11, nr 1, s. 41-54Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is a growing demand for wild caught juvenile fish to supply the market for aquaculture. However, little is known about the genetic effects of juvenile collection from wild populations. There are a number of imminent threats to both aquaculture systems and wild fish populations. Juvenile collection from a single population can for example reduce population’s evolutionary potential as well as the disease resistance within an aquaculture pond. In this study, we investigated the local genetic structure of juvenile mullets collected from five sites around Bagamoyo (Tanzanian mainland) and Zanzibar Island, East Africa. Fish were caught in low tide using a seine net. The fish were morphologically identified, and then genetically identified using direct sequencing of the CO1 gene with cross referencing with the Barcode of Life Database (BOLD) systems.  Molecular variance analyses were used to infer genetic subdivision based on geographic sampling site as well as inferring population structure through the Bayesian assignment test implemented in STRUCTURE 2.3. Our results showed that samples morphologically identified as Mugil cephalus where in fact Valamugil buchanani and we also found evidence of an introgression genome event, where the gene flow from one species may have affected the general gene pool. The Bayesian analysis revealed a clear genetic population structure among the sampled fish; the main difference was the presence of a unique mainland cluster. Our findings may have important implications for management and conservation of mullet fishes in the region and elsewhere.

  • 286.
    Hermann, Stefan
    et al.
    Södertörns högskola, Avdelning Naturvetenskap.
    Berndt, Kurt D
    Södertörns högskola, Avdelning Naturvetenskap.
    Wright, Anthony P H
    Södertörns högskola, Avdelning Naturvetenskap.
    How transcriptional activators bind target proteins2001Inngår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 276, nr 43, s. 40127-40132Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The product of the proto-oncogene c-myc influences many cellular processes through the regulation of specific target genes. Through its transactivation domain (TAD), c-Myc protein interacts with several transcription factors, including TATA-binding protein (TBP). We present data that suggest that in contrast to some other transcriptional activators, an extended length of the c-Myc TAD is required for its binding to TBP. Our data also show that this interaction is a multistep process, in which a rapidly forming low affinity complex slowly converts to a more stable form. The initial complex formation results from ionic or polar interactions, whereas the slow conversion to a more stable form is hydrophobic in nature. Based on our results, we suggest two alternative models for activation domain/target protein interactions, which together provide a single universal paradigm for understanding activator-target factor interactions.

  • 287.
    Herron, John Paul
    Södertörns högskola, Institutionen för livsvetenskaper.
    Immunoaffinity isolation of Btk´s signalosome, a proteomic approach to identifying interacting proteins2006Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    The Signalosome is a term used to define a putative signalling complex, which assembles near the plasma membrane in response to external signals received at cell surface receptors and then migrates towards downstream effectors. It is proposed to regulate the level of intracellular Ca2+ and subsequent downstream signalling events. To date it has been defined to consist of BTK, BLNK, BCAP, VAV, PLCγ2 and PI3K1-4 in B-Cells.

    This work entailed initiating a new proteomic approach to investigate the nature and extent of Bruton’s tyrosine kinase, Btk, involvement in the signalosome – inherently, the aim was to study multiple interactions of Btk with other molecules. By transfecting host cells with a Btk gene-transfer plasmid, virus particles were produced that were used to up-regulate and analyse the expression of Btk in three haematopoietic cell lines: B-cells, Pre-B-cells and a myeloid cancer cell. The construction of a new gene-transfer vector was successfully carried out by plasmid sub-cloning and it was subsequently found to effectively transfect the host cells and produce virus particles. The recombinant virus particles were employed with success in transducing three haematopoietic cell lines and with immunopurification and subsequent gel separation protein signalosome complexes were obtained ready for analysis by mass spectrometrical fingerprinting (to be carried out as a joint effort in Mount Sinai Hospital in Toronto, Canada).

    Fulltekst (pdf)
    FULLTEXT01
  • 288.
    Hjort, Karin
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi.
    Bergström, Maria
    Adesina, Modupe F.
    Jansson, Janet K.
    Smalla, Kornelia
    Sjöling, Sara
    Södertörns högskola, Institutionen för livsvetenskaper, Miljövetenskap. Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi.
    Chitinase genes revealed and compared in bacterial isolates, DNA extracts and a metagenomic library from a phytopathogen-suppressive soil2010Inngår i: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 71, nr 2, s. 197-207Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Soil that is suppressive to disease caused by fungal pathogens is an interesting source to target for novel chitinases that might be contributing towards disease suppression. In this study, we screened for chitinase genes, in a phytopathogen-suppressive soil in three ways: (1) from a metagenomic library constructed from microbial cells extracted from soil, (2) from directly extracted DNA and (3) from bacterial isolates with antifungal and chitinase activities. Terminal restriction fragment length polymorphism (T-RFLP) of chitinase genes revealed differences in amplified chitinase genes from the metagenomic library and the directly extracted DNA, but approximately 40% of the identified chitinase terminal restriction fragments (TRFs) were found in both sources. All of the chitinase TRFs from the isolates were matched to TRFs in the directly extracted DNA and the metagenomic library. The most abundant chitinase TRF in the soil DNA and the metagenomic library corresponded to the TRF103 of the isolate Streptomyces mutomycini and/or Streptomyces clavifer. There were good matches between T-RFLP profiles of chitinase gene fragments obtained from different sources of DNA. However, there were also differences in both the chitinase and the 16S rRNA gene T-RFLP patterns depending on the source of DNA, emphasizing the lack of complete coverage of the gene diversity by any of the approaches used.

  • 289.
    Hjort, Karin
    et al.
    Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi.
    Goldberg, Alina V.
    Tsaousis, Anastasios D.
    Hirt, Robert P.
    Embley, T. Martin
    Diversity and reductive evolution of mitochondria among microbial eukaryotes2010Inngår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 365, nr 1541, s. 713-727Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    All extant eukaryotes are now considered to possess mitochondria in one form or another. Many parasites or anaerobic protists have highly reduced versions of mitochondria, which have generally lost their genome and the capacity to generate ATP through oxidative phosphorylation. These organelles have been called hydrogenosomes, when they make hydrogen, or remnant mitochondria or mitosomes when their functions were cryptic. More recently, organelles with features blurring the distinction between mitochondria, hydrogenosomes and mitosomes have been identified. These organelles have retained a mitochondrial genome and include the mitochondrial-like organelle of Blastocystis and the hydrogenosome of the anaerobic ciliate Nyctotherus. Studying eukaryotic diversity from the perspective of their mitochondrial variants has yielded important insights into eukaryote molecular cell biology and evolution. These investigations are contributing to understanding the essential functions of mitochondria, defined in the broadest sense, and the limits to which reductive evolution can proceed while maintaining a viable organelle.

  • 290.
    Hjort, Karin
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi. Uppsala University.
    Presti, Ilaria
    University of Insubria, Varese, Italy.
    Elväng, Annelie
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi.
    Marinelli, Flavia
    University of Insubria, Varese, Italy.
    Sjöling, Sara
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Biologi.
    Bacterial chitinase with phytopathogen control capacity from suppressive soil revealed by functional metagenomics2014Inngår i: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 98, nr 6, s. 2819-2828Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Plant disease caused by fungal pathogens results in vast crop damage globally. Microbial communities of soil that is suppressive to fungal crop disease provide a source for the identification of novel enzymes functioning as bioshields against plant pathogens. In this study, we targeted chitin-degrading enzymes of the uncultured bacterial community through a functional metagenomics approach, using a fosmid library of a suppressive soil metagenome. We identified a novel bacterial chitinase, Chi18H8, with antifungal activity against several important crop pathogens. Sequence analyses show that the chi18H8 gene encodes a 425-amino acid protein of 46 kDa with an N-terminal signal peptide, a catalytic domain with the conserved active site F175DGIDIDWE183, and a chitinase insertion domain. Chi18H8 was expressed (pGEX-6P-3 vector) in Escherichia coli and purified. Enzyme characterization shows that Chi18H8 has a prevalent chitobiosidase activity with a maximum activity at 35 °C at pH lower than 6, suggesting a role as exochitinase on native chitin. To our knowledge, Chi18H8 is the first chitinase isolated from a metagenome library obtained in pure form and which has the potential to be used as a candidate agent for controlling fungal crop diseases. Furthermore, Chi18H8 may also answer to the demand for novel chitin-degrading enzymes for a broad range of other industrial processes and medical purposes.

    Fulltekst (pdf)
    Hjort et al 2013
  • 291. Hjortswang, H I
    et al.
    Sundås Larsson, Annika
    Södertörns högskola, Avdelning Naturvetenskap.
    Bharathan, G
    Bozhkov, P V
    von Arnold, S
    Vahala, T
    KNOTTED1-like homeobox genes of a gymnosperm, Norway spruce, expressed during somatic embryogenesis2002Inngår i: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690, Vol. 40, nr 10, s. 837-843Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two Norway spruce (Picea abies (L.) Karst.) genes belonging to class I of the KNOTTED1-like homeobox (KNOX) genes, HBK2 and HBK3, were cloned with PCR-based methods. The expression of these and a previously characterised related gene, HBK1, in different organs and during somatic embryogenesis was studied with RTPCR. Transcripts of all three genes were detected in stems, roots and in cone buds, but not in needles. HBK1 and HBK3 are expressed throughout development in a normal cell line with embryogenic potential and in a cell line unable to form somatic embryos. HBK2 is expressed in the normal cell line, but not in the developmentally arrested cell line. This suggests that the HBK2 gene is involved in the somatic embryo development.

  • 292. Hogan, C. J.
    et al.
    Aligianni, S.
    Durand-Dubief, M.
    Persson, J.
    Will, W. R.
    Webster, J.
    Wheeler, L.
    Mathews, C. K.
    Elderkin, S.
    Oxley, D.
    Ekwall, Karl
    Södertörns högskola, Institutionen för livsvetenskaper, Molekylärbiologi. Karolinska Institutet.
    Varga-Weisz, P. D.
    Fission yeast Iec1-Ino80-mediated nucleosome eviction regulates nucleotide and phosphate metabolism2010Inngår i: Molecular and Cellular Biology, ISSN 0270-7306, E-ISSN 1098-5549, Vol. 30, nr 3, s. 657-674Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ino80 is an ATP-dependent nucleosome-remodeling enzyme involved in transcription, replication, and the DNA damage response. Here, we characterize the fission yeast Ino80 and find that it is essential for cell viability. We show that the Ino80 complex from fission yeast mediates ATP-dependent nucleosome remodeling in vitro. The purification of the Ino80-associated complex identified a highly conserved complex and the presence of a novel zinc finger protein with similarities to the mammalian transcriptional regulator Yin Yang 1 (YY1) and other members of the GLI-Krüppel family of proteins. Deletion of this Iec1 protein or the Ino80 complex subunit arp8, ies6, or ies2 causes defects in DNA damage repair, the response to replication stress, and nucleotide metabolism. We show that Iec1 is important for the correct expression of genes involved in nucleotide metabolism, including the ribonucleotide reductase subunit cdc22 and phosphate- and adenineresponsive genes. We find that Ino80 is recruited to a large number of promoter regions on phosphate starvation, including those of phosphate- and adenine-responsive genes that depend on Iec1 for correct expression. Iec1 is required for the binding of Ino80 to target genes and subsequent histone loss at the promoter and throughout the body of these genes on phosphate starvation. This suggests that the Iec1-Ino80 complex promotes transcription through nucleosome eviction.

  • 293.
    Holmberg, Lovisa
    et al.
    Södertörns högskola, Avdelning Naturvetenskap.
    Nygård, Odd
    Södertörns högskola, Avdelning Naturvetenskap.
    Release of ribosome-bound 5S rRNA upon cleavage of the phosphodiester bond between nucleotides A54 and A55 in 5S rRNA2000Inngår i: Biological chemistry (Print), ISSN 1431-6730, E-ISSN 1437-4315, Vol. 381, nr 11, s. 1041-1046Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reticulocyte lysates contain ribosome-bound and free populations of 5S RNA. The free population is sensitive to nuclease cleavage in the internal loop B, at the phosphodiester bond connecting nucleotides A54 and A55. Similar cleavage sites were detected in 5S rRNA in 60S subunits and 80S ribosomes. However, 5S rRNA in reticulocyte polysomes is insensitive to cleavage unless ribosomes are salt-washed. This suggests that a translational factor protects the backbone surrounding A54 from cleavage in polysomes. Upon nuclease treatment of mouse 60S subunits or reticulocyte lysates a small population of ribosomes released its 5S rRNA together with ribosomal protein L5. Furthermore, rRNA sequences from 5.8S, 28S and 18S rRNA were released. In 18S rRNA the sequences mainly originate from the 630 loop and stem (helix 18) in the 5' domain, whereas in 28S rRNA a majority of fragments is derived from helices 47 and 81 in domains III and V, respectively. We speculate that this type of rRNA-fragmentation may mimic a ribosome degradation pathway.

  • 294. Holmgren, A
    et al.
    Arnér, E S J
    Berndt, Kurt D
    Karolinska Institutet.
    Glutaredoxin2002Inngår i: Encyclopedia of Molecular Biology / [ed] Thomas E. Creighton, John Wiley & Sons, 2002Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 295. Holmgren, A
    et al.
    Arnér, E S J
    Berndt, Kurt D
    Karolinska Institutet.
    Thioredoxin2002Inngår i: Encyclopedia of Molecular Biology / [ed] Thomas E. Creighton, John Wiley & Sons, 2002Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 296. Holmgren, A
    et al.
    Arnér, E S J
    Berndt, Kurt D
    Karolinska Institutet.
    Thioredoxin Reductase2002Inngår i: Encyclopedia of Molecular Biology / [ed] Thomas E. Creighton, John Wiley & Sons, 2002Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 297. Hood, D W
    et al.
    Cox, A D
    Wakarchuk, W W
    Schur, M
    Schweda, Elke K H
    Södertörns högskola, Avdelning Naturvetenskap.
    Walsh, S L
    Deadman, M E
    Martin, A
    Moxon, E R
    Richards, J C
    Genetic basis for expression of the major globotetraose-containing lipopolysaccharide from H-influenzae strain Rd (RM118)2001Inngår i: Glycobiology, ISSN 0959-6658, E-ISSN 1460-2423, Vol. 11, nr 11, s. 957-967Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A genetic basis for the biosynthetic assembly of the globotetraose containing lipopolysaccharide (LPS) of Haemophilus influenzae strain RM118 (Rd) was determined by structural analysis of LPS derived from mutant strains. We have previously shown that the parent strain RM118 elaborates a population of LPS molecules made up of a series of related glycoforms differing in the degree of oligosaccharide chain extension from the distal heptose residue of a conserved phosphorylated inner-core element, L-alpha -D-Hepp-(1-->2)-L-alpha -D-Hepp-(1-->3)-[beta -D-Glcp-(1-->4)-]-L-alpha -D-Hepp-(1-->5)-alpha -Kdo. The fully extended LPS glycoform expresses the globotetraose structure, beta -D-GalpNAc-(1-->3)-alpha -D-Galp(1-->4)-beta -D-Galp-(1-->4)-beta -D-Glcp. A fingerprinting strategy was employed to establish the structure of LPS from strains mutated in putative glycosyltransferase genes compared to the parent strain. This involved glycose and linkage analysis on intact LPS samples and analysis of O-deacylated LPS samples by electrospray ionization mass spectrometry and 1D H-1-nuclear magnetic resonance spectroscopy. Four genes, lpsA, lic2A, lgtC, and lgtD, were required for sequential addition of the glycoses to the terminal inner-core heptose to give the globotetraose structure. lgtC and lgtD were shown to encode glycosyltransferases by enzymatic assays with synthetic acceptor molecules. This is the first genetic blueprint determined for H. influenzae LPS oligosaccharide biosynthesis, identifying genes Involved in the addition of each glycose residue.

  • 298. Hood, D W
    et al.
    Randle, G
    Cox, A D
    Makepeace, K
    Li, J J
    Schweda, Elke K H
    Södertörns högskola, Institutionen för kemi, biologi, geografi och miljövetenskap.
    Richards, J C
    Moxon, E R
    Biosynthesis of cryptic lipopolysaccharide glycoforms in Haemophilus influenzae involves a mechanism similar to that required for O-antigen synthesis2004Inngår i: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 186, nr 21, s. 7429-7439Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is generally thought that mucosal bacterial pathogens of the genera Haemophilus, Neisseria, and Moraxella elaborate lipopolysaccharide (LPS) that is fundamentally different from that of enteric organisms that express O-specific polysaccharide side chains. Haemophilus influenzae elaborates short-chain LPS that has a role in the pathogenesis of H. influenzae infections. We show that the synthesis of LPS in this organism can no longer be as clearly distinguished from that in other gram-negative bacteria that express an O antigen. We provide evidence that a region of the H. influenzae genome, the hmg locus, is involved in the synthesis of glycoforms in which tetrasaccharide units are added en bloc, not stepwise, to the normal core glycoforms, similar to the biosynthesis of an O-antigen.

  • 299. Hood, Derek W.
    et al.
    Deadman, Mary E.
    Engskog, Mikael K. R.
    Vitiazeva, Varvara
    Makepeace, Katherine
    Schweda, Elke K H
    Södertörns högskola, Institutionen för livsvetenskaper, Kemi.
    Moxon, Richard
    Genes required for the synthesis of heptose-containing oligosaccharide outer core extensions in Haemophilus influenzae lipopolysaccharide2010Inngår i: Microbiology, ISSN 1350-0872, E-ISSN 1465-2080, Vol. 156, s. 3421-3431Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heptose-containing oligosaccharides (OSs) are found in the outer core of the lipopolysaccharide (LPS) of a subset of non-typable Haemophilus influenzae (NTHi) strains. Candidate genes for the addition of either L-glycero-D-manno-heptose (LD-Hep) or D-glycero-D-manno-heptose (DD-Hep) and subsequent hexose sugars to these OSs have been identified from the recently completed genome sequences available for NTHi strains. losA1/losB1 and losA2/losB2 are two sets of related genes in which losA has homology to genes encoding glycosyltransferases and losB to genes encoding heptosyltransferases. Each set of genes is variably present across NTHi strains and is located in a region of the genome with an alternative gene organization between strains that contributes to LPS heterogeneity. Dependent upon the strain background, the LPS phenotype, structure and serum resistance of strains mutated in these genes were altered when compared with the relevant parent strain. Our studies confirm that losB1 and losB2 usually encode DD-heptosyl- and LD-heptosyl transferases, respectively, and that losA1 and losA2 encode glycosyltransferases that play a role in OS extensions of NTHi LPS.

  • 300. Houliston, R. Scott
    et al.
    Koga, Michiaki
    Li, Jianjun
    Jarrell, Harold C.
    Richards, James C.
    Vitiazeva, Varvara
    Schweda, Elke K. H.
    Södertörns högskola, Institutionen för livsvetenskaper.
    Yuki, Nobuhiro
    Gilbert, Michel
    A Haemophilus influenzae strain associated with fisher syndrome expresses a novel disialylated ganglioside mimic2007Inngår i: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 46, nr 27, s. 8164-8171Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The non-typeable Haemophilus influenzae strain DH1 was isolated from a 25 year old male patient with Fisher syndrome, a postinfectious autoimmune condition characterized by the presence of anti-GQ1b IgG antibodies that target and initiate damage to peripheral nerves. DH1 was found to display an alpha NeuAc(2-8)alpha NeuAc(2-3)beta Gal branch bound to the tetraheptosyl backbone core of its lipooligosaccharide (LOS). The novel sialylation pattern was found to be dependent on the activity of a bifunctional sialyltransferase, Lic3B, which catalyzes the addition of both the terminal and subterminal sialic acid residues. Patient serum IgGs bind to DH1 LOS, and the reactivity is significantly influenced by the presence of sialylated glycoforms. The display by DH1, of a surface glycan that mimics the terminal trisaccharide portion of disialosyl-containing gangliosides, provides strong evidence for its involvement in the development of Fisher syndrome.

3456789 251 - 300 of 824
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • harvard-anglia-ruskin-university
  • apa-old-doi-prefix.csl
  • sodertorns-hogskola-harvard.csl
  • sodertorns-hogskola-oxford.csl
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf