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  • 1. Agianian, Bogos
    et al.
    Lesch, Christine
    Loseva, Olga
    Dushay, Mitchell S.
    Södertörn University, School of Life Sciences. Uppsala University.
    Preliminary characterization of hemolymph coagulation in Anopheles gambiae larvae2007In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 31, no 9, p. 879-888Article in journal (Refereed)
    Abstract [en]

    Hemolymph coagulation is a first response to injury, impeding infection, and ending bleeding. Little is known about its molecular basis in insects, but clotting factors have been identified in the fruit fly Drosophila melanogaster. Here, we have begun to study coagulation in the aquatic larvae of the malaria vector mosquito Anopheles gambiae using methods developed for Drosophila. A delicate clot was seen by light microscopy, and pullout and proteomic analysis identified phenoloxidase and apolipophorin-I as major candidate clotting factors. Electron microscopic analysis confirmed clot formation and revealed it contains fine molecular sheets, most likely a result of lipophorin assembly. Phenoloxidase appears to be more critical in clot formation in Anopheles than in Drosophila. The Anopheles larval clot thus differs in formation, structure, and composition from the clot in Drosophila, confirming the need to study coagulation in different insect species to learn more about its evolution and adaptation to different lifestyles.

  • 2.
    Bidla, Gawa
    et al.
    Stockolms universitet.
    Lindgren, Malin
    Södertörn University, School of Life Sciences.
    Theopold, Ulrich
    Stockholms universitet.
    Dushay, Mitchell S.
    Södertörn University, School of Life Sciences.
    Hemolymph coagulation and phenoloxidase in Drosophila larvae2005In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 29, no 8, p. 669-679Article in journal (Refereed)
    Abstract [en]

    Hemolymph coagulation is a first response to wounding in insects. Although studies have been performed in large-bodied insects such as the moth Galleria mellonella, less is known about clotting in Drosophila melanogaster, the insect most useful for genetic and molecular analyses of innate immunity. Here we show the similarities between clots in Drosophila and Galleria by light- and electron microscopy. Phenoloxidase changes the Drosophila clot's physical properties through cross-linking and melanization, but it is not necessary for preliminary soft clot formation. Bacteria associate with the clot, but this alone does not necessarily kill them. The stage is now set for rapid advances in our understanding of insect hemolymph coagulation, its roles in immune defense and wound healing, and for a more comprehensive grasp of the insect immune system in general.

  • 3.
    Bräutigam, Lars
    et al.
    Södertörn University, School of Life Sciences, Molecular biology.
    Hillmer, Janine M.
    Södertörn University, School of Life Sciences, Molecular biology.
    Söll, Iris
    Södertörn University, School of Life Sciences, Molecular biology.
    Hauptmann, Giselbert
    Södertörn University, School of Life Sciences, Molecular biology.
    Localized Expression of Urocortin Genes in the Developing Zebrafish rain2010In: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 518, no 15, p. 2978-2995Article in journal (Refereed)
    Abstract [en]

    The corticotropin-releasing hormone (CRH) family consists of four aralogous genes, CRH and urocortins (UCNs) 1, 2, and 3. In a previous tudy, we analyzed CRH in the teleost model organism zebrafish and its ranscript distribution in the embryonic brain. Here, we describe ull-length cDNAs encoding urotensin 1 (UTS1), the teleost UCN1 rtholog, and UCN3 of zebrafish. Major expression sites of uts1 in adult ebrafish are the caudal neurosecretory system and brain. By using T-PCR analysis, we show that uts1 mRNA is also present in ovary, aternally contributed to the embryo, and expressed throughout embryonic evelopment. Expression of ucn3 mRNA was detected in a range of adult issues and during developmental stages from 24 hours post fertilization nward. Analysis of spatial transcript distributions by whole-mount in itu hybridization revealed limited forebrain expression of uts1 and cn3 during early development. Small numbers of uts1-synthesizing eurons were found in subpallium, hypothalamus, and posterior iencephalon, whereas ucn3-positive cells were restricted to elencephalon and retina. The brainstem was the main site of uts1 and cn3 synthesis in the embryonic brain. uts1 Expression was confined to he midbrain tegmentum; distinct hindbrain cell groups, including locus oeruleus and Mauthner neurons; and the spinal cord. ucn3 Expression was ocalized to the optic tectum, serotonergic raphe, and distinct hombomeric cell clusters. The prominent expression of uts1 and ucn3 in rainstem is consistent with proposed roles of CRH-related peptides in tress-induced modulation of locomotor activity through monoaminergic rainstem neuromodulatory systems. J. Comp. Neurol. 518:2978-2995, 2010.

  • 4.
    Chandrasekar, Gayathri
    et al.
    Södertörn University, School of Life Sciences.
    Lauter, Gilbert
    Södertörn University, School of Life Sciences.
    Hauptmann, Giselbert
    Södertörn University, School of Life Sciences.
    Distribution of corticotropin-releasing hormone in the developing zebrafish brain2007In: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 505, no 4, p. 337-351Article in journal (Refereed)
    Abstract [en]

    Corticotropin-releasing hormone (CRH) plays a central role in the physiological regulation of the hypothalamus-pituitary-adrenal/interrenal axis mediating endocrine, behavioral, autonomic, and immune responses to stress. Despite the wealth of knowledge about the physiological roles of CRH, the genetic mechanisms by which CRH neurons arise during development are poorly understood. As a first step toward analyzing the molecular and genetic pathways involved in CRH lineage specification, we describe the developmental distribution of CRH neurons in the embryonic zebrafish, a model organism for functional genomics and developmental biology. We searched available zebrafish expressed sequence tag (EST) databases for CRH-like sequences and identified one EST that contained the complete zebrafish CRH open reading frame (ORF). The CRH precursor sequence contained a signal peptide, the CRH peptide, and a cryptic peptide with a conserved sequence motif. RT-PCR analysis showed crh expression in a wide range of adult tissues as well as during embryonic and larval stages. By whole-mount in situ hybridization histochemistry, discrete crh-expressing cell clusters were found in different parts of the embryonic zebrafish brain, including telencephalon, preoptic region, hypothalamus, posterior tuberculum, thalamus, epiphysis, midbrain tegmentum, and rostral hindbrain and in the neural retina. The localization of crh mRNA within the preoptic region is consistent with the central role of CRH in the teleost stress response through activation of the hypothalamic-pituitary-interrenal axis. The widespread distribution of CRH-synthesizing cells outside the preoptic region suggests additional functions of CRH in the embryonic zebrafish brain.

  • 5.
    Hallgren, Stefan
    et al.
    Södertörn University College, School of Life Sciences.
    Kitambi, Satish Srinivas
    Karolinska Institutet.
    Cloning, sequencing and In situ localisation of guppy brain aromatase, cyp19bManuscript (preprint) (Other academic)
    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.

  • 6.
    Hallgren, Stefan
    et al.
    Södertörn University College, School of Life Sciences.
    Olsén, K Håkan
    Södertörn University College, School of Life Sciences.
    Impacts of synthetic oestrogen and antioestrogen treatments on courtship and mating behaviours in male guppies (Poecilia reticulata)Manuscript (preprint) (Other academic)
    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.

  • 7.
    Henriksson, Oskar
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Stockholms universitet.
    Genetic connectivity of fish in the Western Indian Ocean2013Doctoral thesis, comprehensive summary (Other academic)
    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.

  • 8.
    Henriksson, Oskar
    et al.
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Stockholms universitet.
    Larsson, Josefine
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Environmental Science.
    Grahn, Mats
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology.
    Temporal genetic variability of landed Siganus sutor reveals a mixed stock fishery in coastal KenyaManuscript (preprint) (Other academic)
    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.

  • 9.
    Jaensson, Alia
    Södertörn University, School of Life Sciences.
    Effects of glyphosate on olfactory mediated endorcine responses to female odours and reproductive behaviour in male brown trout (slamo trutta)In: Ecotoxicology, ISSN 0963-9292, E-ISSN 1573-3017Article in journal (Refereed)
  • 10.
    Jaensson, Alia
    et al.
    Södertörn University, School of Life Sciences.
    Olsén, K. Håkan
    Södertörn University, School of Life Sciences.
    Prolonged cypermthrin exposure increases sex steroid plasma hormone levels in mature male brown trout (Salmo trutta) parr in spawning groupsIn: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514Article in journal (Refereed)
  • 11.
    Lesch, Christine
    et al.
    Stockholms universitet.
    Goto, Akira
    UPR9022 du CNRS, IBMC, Strasbourg, France.
    Lindgren, Malin
    Södertörn University, School of Life Sciences.
    Bidla, Gawa
    Stockholms universitet.
    Dushay, Mitchell S.
    Södertörn University, School of Life Sciences. Uppsala University.
    Theopold, Ulrich
    Stockholms universitet.
    A role for Hemolectin in coagulation and immunity in Drosophila melanogaster2007In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 31, no 12, p. 1255-1263Article in journal (Refereed)
    Abstract [en]

    Hemolectin has been identified as a candidate clotting factor in Drosophila. We reassessed the domain structure of Hemolectin (Hml) and propose that instead of C-type lectin domains, the two discoidin domains are most likely responsible for the protein's lectin activity. We also tested Hml's role in coagulation and immunity in Drosophila. Here we describe the isolation of a new hml allele in a forward screen for coagulation mutants, and our characterization of this and two other hml alleles, one of which is a functional null. While loss of Hml had strong effects on larval hemolymph coagulation ex vivo, mutant larvae survived wounding. Drosophila thus possesses redundant hemostatic mechanisms. We also found that loss of Hml in immune-handicapped adults rendered them more sensitive to Gram(-) bacteria infection. This demonstrates an immunological role of this clotting protein and reinforces the importance of the clot in insect immunity.

  • 12.
    Lindgren, Malin
    et al.
    Södertörn University, School of Life Sciences.
    Riazi, Raha
    Stockholms universitet.
    Lesch, Christine
    Stockholms universitet.
    Willielinsson, Christine
    Stockholms universitet.
    Theopold, Ulrich
    Stockholms universitet.
    Dushay, Mitchell S.
    Södertörn University, School of Life Sciences.
    Fondue and transglutaminase in the Drosophila larval clot2008In: Journal of insect physiology, ISSN 0022-1910, E-ISSN 1879-1611, Vol. 54, no 3, p. 586-592Article in journal (Refereed)
    Abstract [en]

    Hemolymph coagulation is vital for larval hemostasis and important in immunity, yet the molecular basis of coagulation is not well understood in insects. Of the larval clotting factors identified in Drosophila, Fondue is not conserved in other insects, but is notable for its effects on the clot's physical properties.. a possible function in the cuticle, and for being a substrate of transglutaminase. Transglutaminase is the only mammalian clotting factor found in Drosophila, and as it acts in coagulation in other invertebrates, it is also likely to be important in clotting in Drosophila. Here we describe a Fondue-GFP fusion construct that labels the cuticle and clot, and show that chemical inhibition and RNAi knockdown of the Drosophila transglutaminase gene affect clot properties and composition in ways similar to knockdown of the fon gene. Thus, Fondue appears to be incorporated into the cuticle and is a key transglutaminase substrate in the clot. This is also the first direct functional confirmation that transglutaminase acts in coagulation in Drosophila.

  • 13.
    Porseryd, Tove
    et al.
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Environmental Science.
    Volkova, Kristina
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Örebro University.
    Reyhanian Caspillo, Nasim
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Örebro university.
    Källman, Thomas
    Uppsala university.
    Porsch-Hällström, Inger
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology.
    Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behaviorManuscript (preprint) (Other academic)
  • 14.
    Souter, Petra
    Södertörn University, School of Life Sciences. Stockholms universitet, Zoologiska institutionen.
    Causes and consequences of spatial genetic variation in two species of scleractinian coral in East Africa: Levels of genetic differentiation and intraspecific diversity of Pocillopora damicornis and Platygyra daedalea2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The work presented in this thesis is a study of the spatial genetic structure of two species of scleractinian corals, Pocillopora damicornis and Platygyra daedalea. The overall objective was to investigate the current capacity of MPAs to preserve and restore coral reefs and to contribute information to improve management decisions. Samples were taken from 11 sites along the coast of Kenya. In addition P. daedalea was sampled from one site on each of the islands of Unguja (Zanzibar archipelago) and Mafia in Tanzania.

    Populations of P. daedalea were largely panmictic within two lagoonal clusters. Samples obtained from two off-shore sites were more similar to the samples from the island samples in Tanzania than they were to proximal lagoonal samples. Off-shore and island samples were also significantly more genetically diverse in both the level of heterozygosity and allelic richness. Migration predominantly occurs from off-shore and island reefs toward the lagoonal reefs. The investigated populations of P. damicornis exhibited limited genetic neighbourhoods and highly localised recruitment and a significant pair-wise differentiation was found between a majority of the sampling sites. These results are probably a cause of the genetic bottleneck caused by the high mortality of this species during the 1998 coral bleaching event and reflects subsequent founder events and variable recruitment patterns, causing genetically distinct populations.

    P. damicornis also displayed plastic reproduction, with some sites being dominated by large numbers of identical multilocus genotypes. The clonal colonies showed signs of being genotypcially distinct as they were all found to be homozygotes for a specific allele at one of the microsatellite loci. Due to the decreased genotypic diversity, associated with the high rate of clonal reproduction, the level of genetic diversity and allelic richness tended to be lower at unmanaged reefs. Also, the probability of encountering clonally produced individuals was significantly greater on unprotected reefs compared with protected reefs.

    Canonical discriminant analysis of measurements of ten skeletal characters identified two distinct morphological types of P. daedalea. Analysis of molecular variance showed that morphotype explained a larger proportion of the genetic divergence than did the geographic distribution of sites sampled within MMP. However, phylogenetic analysis of rRNA sequences showed no evidence of sequence divergence, neither between morphotypes nor between samples of P. daedalea from MMP and samples of Platygyra sinensis from Hong Kong.

    In summary, these data demonstrate the importance of incorporating multiple species and aspects when addressing the issue of connectivity and its implications for management. P. damicornis would benefit from localised management efforts to preserve its genotypic diversity, whereas P. daedalea would benefit from larger reserves to minimise the risk of loosing rare alleles through genetic drift which would further reduce its genetic diversity on lagoonal reefs. It also brings the subject of morphological characteristics and local adaptation into focus by revealing possible genetic divergence between two morphotypes of P. daedalea and two reproductive modes in P. damicornis.

  • 15.
    Svanberg, Ingvar
    Södertörn University College, School of Gender, Culture and History, Study of religions.
    "Deras mistande rör mig så hierteligen": Linné och hans sällskapsdjur2007In: Svenska Linnésällskapets årsskrift, ISSN 0375-2038, p. 11-108Article in journal (Other academic)
  • 16.
    Volkova, Kristina
    et al.
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Örebro University.
    Reyhanian Caspillo, Nasim
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology. Örebro university.
    Porseryd, Tove
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Environmental Science.
    Hallgren, Stefan
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies. Uppsala university.
    Dinnetz, Patrik
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Environmental Science.
    Olsén, Håkan
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology.
    Porsch Hällström, Inger
    Södertörn University, School of Natural Sciences, Technology and Environmental Studies, Biology.
    Transgenerational effects of 17α-Ethinyl Estradiol on anxiety behaviour in the guppy, Poecilia reticulata2015In: General and Comparative Endocrinology, ISSN 0016-6480, E-ISSN 1095-6840, Vol. 223, p. 66-72Article in journal (Refereed)
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