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  • 251.
    Jansson, Mija
    Stockholm University, Faculty of Science, Department of Zoology.
    Assessing inbreeding and loss of genetic variation in canids, domestic dog (Canis familiaris) and wolf (Canis lupus), using pedigree data2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Genetic variation is necessary to maintain the ability of wild and domestic populations to genetically adapt to changed selective pressures. When relationships among individuals are known, conservation genetic management can be based on statistical pedigree analysis. Such approaches have traditionally focused on wild animal conservation breeding in captivity. In this thesis, I apply pedigree-based techniques to domestic and wild animal populations, focusing on two canids – the domestic dog and the wild wolf.

    Main objectives include to 1) develop a means for making any pedigree fit the input requirements of the software Population Management x (PMx) and to use this program to 2) investigate rate of inbreeding and loss of genetic variation in dog breeds, including possible correlations between recent inbreeding and health problems, 3) estimate effects on inbreeding of the 2010 hunt of the endangered Swedish wolf population, and to 4) evaluate the potential to genetically support this wolf population through cross-fostering releases of zoo bred pups from a conservation breeding program.

    Results include successfully developing the converter program mPed (Paper I) and applying both mPed and PMx to dog and wolf pedigrees. I found extensive loss of genetic variation and moderate rates of recent inbreeding in 26 dog breeds, but no major difference in these parameters between breeds classified as “healthy” vs. “unhealthy“ (Paper II). I found average inbreeding coefficients to more than double (from F=0.03 to 0.07) and founder genetic variation to decrease by c. 30 percent over the past few decades in traditional Swedish dog breeds identified as being of conservation concern (Paper IV). Hunting will make it less likely to reach genetically based Favourable Conservation Status criteria for the Swedish wild wolf population (Paper III), but release of zoo bred wolves through cross-fostering may potentially almost double founder genetic variation of this population (Paper V).

  • 252.
    Jansson, Mija
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Ståhl, Ingvar
    Laikre, Linda
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    mPed: a computer program for converting pedigree data to a format used by the PMx-software for conservation genetic analysis2013In: Conservation Genetics Resources, ISSN 1877-7252, E-ISSN 1877-7260, Vol. 5, no 3, p. 651-653Article in journal (Refereed)
    Abstract [en]

    There is a growing need for conservation genetic management of animal populations when individual relatedness data (pedigrees) are available. Such data can be used to monitor rates of inbreeding and loss of genetic diversity. Traditionally, pedigree analysis for conservationmanagement has focused on zoo populations of threatened wild animals; available software has been developed in that context. Population Management x (PMx) is a free software for estimating genetic parameters including inbreeding, kinship, founder allele contribution and survival. PMx is an accessory program to the zoo studbook platform Single Population Analysis and Records Keeping System (SPARKS) and is not easily applied outside this platform, but such use is of interest for various domestic breeds or wild populations. We developed a converter program (mPed) for making pedigrees of any studbook format fitting the input requirements of PMx. mPed can be downloaded free at www.popgen.su.se/mped.php

  • 253.
    Janz, Niklas
    Stockholm University.
    Ecology and evolution of butterfly host plant range1999Doctoral thesis, comprehensive summary (Other academic)
  • 254.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Ehrlich and Raven Revisited: Mechanisms Underlying Codiversification of Plants and Enemies2011In: Annual Review of Ecology, Evolution and Systematics, ISSN 1543-592X, E-ISSN 1545-2069, Vol. 42, p. 71-89Article, review/survey (Refereed)
    Abstract [en]

    After almost 50 years of scrutiny, the ideas that Ehrlich and Raven presented in their classical paper on the coevolution between butterflies and plants are still very much alive. Much of this interest has involved the potential for codiversification, both in how the interaction itself diversifies and how the interaction affects modes and rates of speciation. Despite high levels of conservatism and specialization, diversification of the interaction appears to be mainly a consequence of host shifts, but this somewhat paradoxical conclusion can be understood by an appreciation of the ecological as well as genetic mechanisms behind host shifts. There are several ways that the interaction can influence speciation, with or without host-plant-based di-vergent selection on reproductive barriers. One current debate is over the relative importance of radiations following shifts to new adaptive zones and elevated rates of speciation in groups with plastic and diverse host use.

  • 255.
    Janz, Niklas
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Bergström, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Johansson, Josefin
    Frequency dependence of host plant choice within and between patches: a large cage experiment2005In: Evolutionary Ecology, ISSN 0269-7653, E-ISSN 1573-8477, Vol. 19, no 3, p. 289-302Article in journal (Refereed)
    Abstract [en]

    Oviposition preference is considered to be one of the most important factors behind patterns of host use among herbivorous insects. However, preference is defined as host plant choice under equal host abundance and availability, and it is likely that frequency-dependent effects will alter the actual pattern of host use beyond what preference trials reveals. The effects of such alterations are poorly known but could be important for the understanding of specialization and host shifts. We investigated how changes in frequency of a preferred and a less preferred host affected movement patterns and egg deposition within and among patches in a polyphagous butterfly, Polygonia c-album. Two experiments were carried out in large (8 × 30 m) outdoor cages, artificially divided into distinct patches with different frequencies of the two hosts: one that allowed for limited movement between patches and one that did not. There was a clear effect of frequency on patch selection; females spent more time in and laid more eggs in patches with a high frequency of the preferred host, which will potentially have a large effect on host use by modifying encounter rates in favor of the preferred host. However, there was no significant frequency-dependent plant choice within patches in any experiment. Instead, results indicate that females are distributing their eggs among plants species according to specific likelihoods of oviposition, independent of encounter rates, which is compatible with a strategy of risk-spreading.

  • 256.
    Janzon, Lars-Åke
    Stockholm University.
    Taxonomical and biological studies of Tephritis species (Diptera) and their parasitoids (Hymenoptera)1984Doctoral thesis, comprehensive summary (Other academic)
  • 257.
    Jaros, Peter P.
    et al.
    Rheinische Friedrich-Wilhelms-Universität, Germany.
    Dircksen, Heinrich
    Rheinische Friedrich-Wilhelms-Universität, Germany.
    Keller, Rainer
    Rheinische Friedrich-Wilhelms-Universität, Germany.
    Occurrence of immunoreactive enkephalins in a neurohemal organ and other nervous structures in the eyestalk of the shore crab, Carcinus maenas L. (Crustacea, Decapoda)1985In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 241, no 1, p. 111-117Article in journal (Refereed)
    Abstract [en]

    Light-microscopical observations with immunofluorescence and peroxidase staining procedures revealed leu-enkephalin-like immunoreactivity in axon profiles of the sinus gland (SG) and in single small neurons in the optic ganglia of the eyestalk of Carcinus maenas. Electron microscopy of the SG showed reactivity to be associated with neurosecretory granules 82±23 nm in diameter. High performance liquid chromatography of SG-extracts revealed radioimmunoreactive substances with the retention times of synthetic met- and leu-enkephalin and met-enkephalin-Arg6-Phe7, respectively.

  • 258. Jensen, O. P.
    et al.
    Hansson, Sture
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Didrikas, T.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Stockwell, J. D.
    Hrabik, T. R.
    Axenrot, T.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Kitchell, J. F.
    Foraging, bioenergetic and predation constraints on diel vertical migration: field observations and modelling of reverse migration by young-of-the-year herring Clupea harengus2011In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 78, no 2, p. 449-465Article in journal (Refereed)
    Abstract [en]

    Diel vertical migration (DVM) of young-of-the-year (YOY) herring Clupea harengus and one of their major predators, pikeperch Sander lucioperca, was examined using bottom-mounted hydroacoustics in Himmerfjarden, a brackish bay of the Baltic Sea, in summer. In contrast to previous studies on DVM of C. harengus aggregated across size and age classes, YOY C. harengus showed a reverse DVM trajectory, deeper at night and, on average, shallower during the day. This pattern was observed consistently on five acoustic sampling occasions in 3 years and was corroborated by two out of three trawl surveys. Large acoustic targets (target strength >-33 dB, probably piscivorous S. lucioperca > 45 cm) showed a classic DVM trajectory, shallow at night and deeper during the day. Variability in YOY C. harengus vertical distribution peaked at dawn and dusk, and their vertical distribution at midday was distinctly bimodal. This reverse DVM pattern was consistent with bioenergetic model predictions for YOY C. harengus which have rapid gut evacuation rates and do not feed at night. Reverse DVM also resulted in low spatial overlap with predators.

  • 259. Johanson, K.A.
    et al.
    Kjer, K
    Malm, Tobias
    Stockholm University, Faculty of Science, Department of Zoology.
    Testing the monophyly of the New Zealand and Australian endemic family Conoesucidae Ross based on combined molecular and morphological data (Insecta: Trichoptera: Sericostomatoidea)2009In: Zoologica Scripta, ISSN 0300-3256, E-ISSN 1463-6409, Vol. 38, no 6, p. 563-573Article in journal (Refereed)
    Abstract [en]

    Conoesucidae (Trichoptera, Insecta) are restricted to SE Australia, Tasmania and New Zealand. The family includes 42 described species in 12 genera, and each genus is endemic to either New Zealand or Australia. Although monophyly has been previously assumed, no morphological characters have been proposed to represent synapomorphies for the group. We collected molecular data from two mitochondrial genes (16S and cytochrome oxidase I), one nuclear gene (elongation factor 1-alpha) (2237-2277 bp in total), and 12 morphological characters to produce the first phylogeny of the family. We combined the molecular and morphological characters and performed both a maximum parsimony analysis and a Bayesian analysis to test the monophyly of the family, and to hypothesize the phylogeny among its genera. The parsimony analysis revealed a single most parsimonious tree with Conoesucidae being a monophyletic taxon and sistergroup to the Calocidae. The Bayesian inference produced a distribution of trees, the consensus of which is supported with posterior probabilities of 100% for 15 out of 22 possible ingroup clades including the most basal branch of the family, indicating strong support for a monophyletic Conoesucidae. The most parsimonious tree and the tree from the Bayesian analysis were identical except that the ingroup genus Pycnocentria changed position by jumping to a neighbouring clade. Based on the assumption that the ancestral conoesucid species was present on both New Zealand and Australia, a biogeographical analysis using the dispersal-vicariance criteria demonstrated that one or two (depending on which of the two phylogenetic reconstructions were applied) sympatric speciation events took place on New Zealand prior to a single, late dispersal from New Zealand to Australia.

  • 260.
    Johanson, Kjell Arne
    et al.
    Swedish Museum of Natural History, Department of Entomology.
    Espeland, Marianne
    Stockholm University, Faculty of Science, Department of Zoology.
    Phylogeny of the Ecnomidae (Insecta: Trichoptera)2010In: Cladistics, ISSN 0748-3007, E-ISSN 1096-0031, Vol. 26, no 1, p. 36-48Article in journal (Refereed)
    Abstract [en]

    Ecnomidae are a family of seven previously accepted extant genera having a typical Gondwanan distribution, except one genus (Ecnomus) being widely distributed also in the Oriental and Palearctic regions. We analysed a molecular data set of 3379 characters representing the sum of four different protein-coding genes (COI, CAD, EF-1a and POL-II). Six equally most parsimonious trees were generated from the combined data set, distributed into two distinct islands. In all maximum parsimony (MP) trees the Ecnomidae is monophyletic when the genus Zelandoptila (Psychomyiidae) is included. The sister group to Ecnomidae including Zelandoptila is Pseudoneureclipsis, previously classified in the other families. This sister-group relationship contradicts earlier findings that the Polycentropodidae are the sister group to Ecnomidae. A Bayesian analysis resulted in a monophyletic Ecnomidae when accepting inclusion of Pseudoneureclipsis, which contradicts the results from the MP analysis by leaving Zelandoptila as the sister group to Ecnomidae including Pseudoneureclipsis. In the majority rule tree from this analysis Polycentropodidae form the sister group to Ecnomidae. We were not able to obtain a monophyletic Ecnomus due to the inclusion of Psychomyillodes. We conclude that the genus Zelandoptila or Pseudoneureclipsis probably belongs to the Ecnomidae, and that Psychomyiellodes and Ecnomus are synonyms. Three additional, as yet undescribed monotypic genera from Australia and New Caledonia remain to be erected in Ecnomidae.

  • 261.
    Johansson, Agneta
    Stockholm University, Faculty of Science, Department of Zoology.
    Territorial dynamics and marking behaviour in male roe deer1996Doctoral thesis, comprehensive summary (Other academic)
  • 262.
    Johansson, Anna-Karin
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sellström, Ulla
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Lindberg, Peter
    Bignert, Anders
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    De Wit, Cynthia A
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Polybrominated diphenyl ether congener patterns, hexabromocyclododecane, and brominated biphenyl 153 in eggs of peregrine falcons (Falco peregrinus) breeding in Sweden.2009In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 28, no 1, p. 9-17Article in journal (Refereed)
    Abstract [en]

    Previous analyses of 52 peregrine falcon (Falco peregrinus) eggs collected from two wild and one captive population in Sweden 1987 through 1999 were complemented by including additional polybrominated diphenyl ether (PBDE) congeners (BDE-35, -183, -184, -185, -196, -197, -203, and -207). In addition, 31 eggs not previously analyzed for hexabromocyclododecane (HBCD) and BDE-209 were analyzed for these. Geometric mean concentrations of BPBDEs, HBCD, and the hexabrominated biphenyl (BB-153) were 3,100, 140, and 81 ng/g of lipid weight for the southern population; 2,500, 110, and 84 ng/g of lipid weight for the northern population; and 47, not detected, and 8 ng/g of lipid weight for the captive population. The BDE congener pattern was dominated by BDE-153, -99, and -100. The results were used to investigate whether a difference in PBDE congener pattern could be distinguished between the two wild populations of peregrine falcons due to different diets, as the southern population preys mainly on birds belonging to the terrestrial food chain while the northern population preys more on aquatic birds. A multivariate t-test showed a subtle but significant (p < 0.001) difference in PBDE congener pattern between the two populations. However, our hypothesis that higher-brominated congeners of PBDEs would be present to a greater extent in the terrestrial food chain was not supported by principal component analysis. The average brood size for individual females from the southern population decreased with increasing concentrations of IPBDE in the eggs (log-linear regression p < 0.01).

  • 263.
    Johansson, Birgitta
    Stockholm University, Faculty of Science, Department of Zoology.
    Oxygen deficiency and the ecology of Baltic macrobenthos1997Doctoral thesis, comprehensive summary (Other academic)
  • 264.
    Johansson, Sif
    Stockholm University, Faculty of Science, Department of Zoology.
    Regulating factors for coastal zooplankton community structure in the northern Baltic proper1992Doctoral thesis, comprehensive summary (Other academic)
  • 265.
    Johansson, Ulf. S.
    Stockholm University, Faculty of Science, Department of Zoology.
    Clades in the "higher land bird assemblage"2002Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis summarizes the results of several phylogenetic studies of birds included in the “higher land bird assemblage” (Anomalogonatae sensu Beddard 1898). The phylogenetic analyses are primarily based on gene sequences obtained from the nuclear genome (exons of the c-myc and RAG-1 genes and an intron of the myoglobin gene).  Monophyly of the “higher land bird assemblage” has previously been suggested based on the loss of the ambiens muscle in these birds. However, in agreement with other molecular studies, the results presented do not corroborate the monophyly of this group, although the tree is basically unresolved to due lack of statistical support (Bootstrap, parsimony jackknifing and Bayesian inference). Of the groups included in the “higher land bird assemblage”, Strigiformes (owls), Apodiformes (swifts and hummingbirds), Coliiformes (mousebirds), Trogoniformes (trogons), Piciformes (e.g., woodpeckers, barbets, toucans, puffbirds, jacamars) and Passeriformes (passerines) are supported as monophyletic, whereas Caprimulgiformes (e.g., nightjars, oilbird, and owletnightjars) and Coraciiformes (e.g., rollers, cuckoo-rollers, bee-eaters, kingfishers, hoopoes, hornbills) are not. Among the caprimulgiform birds, the owlet-nightjars (Aegothelidae) are found to be closer to the swifts and hummingbirds (Apodiformes) than to other caprimulgiforms.  In addition, the results indicate that the cuckoo-roller (Leptosomatidae) is not associated with rollers and ground-rollers as suggested by some previous studies. Instead, the rollers and ground-rollers (Coracioidea) are probably sister group to a clade containing todies, motmots, kingfishers, and bee-eaters (Alcedini). Hoopoes, woodhoopoes, and hornbills are monophyletic (Bucerotimorphae). As in many previous analyses, the relationships between Strigiformes, Apodiformes, Coliiformes, Trogoniformes, Piciformes, Passeriformes, Leptosomatidae, Coracioidea, Alcedini, and Bucerotimorphae are unresolved, which could indicate that these groups underwent a rapid evolution, probably in the late Cretaceous – early Tertiary.   

  • 266. Johard, Helena Anna Dagmar
    Neuropeptide signaling in insects: peptide binding sites, tachykinin receptors and SNAP-252003Doctoral thesis, comprehensive summary (Other academic)
  • 267. Johnen, Christa
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Changes in haemolymph ecdysteroid levels and CNS contents of crustacean cardioactive peptide-immunoreactivity during the moult cycle of the isopod Oniscus asellus1995In: Netherlands journal of zoology (Print), ISSN 0028-2960, E-ISSN 1568-542X, Vol. 45, p. 38-40Article in journal (Refereed)
    Abstract [en]

    By use of newly developed enzyme immunoassays for ecdysteroids (ECD) and crustacean cardioactive peptide (CCAP) it was found (1) that in the isopod Oniscus asellus a peak occurs of hemolymph (HL)-ECD contents in prcmoult stages followed by a second but smaller peak 1 h after posterior ecdysis, and (2) that concomitantly with a drop in the first ECD-peak, CCAP-contcnts of the ventral nerve cord rise tenfold basal level around posterior ecdysis. This suggests that CCAP plays a role in isopod moulting processes.

  • 268.
    Jorde, Per Erik
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Temporal allele frequency change in populations with overlapping generations: estimation of effective size of natural populations as exemplified using brown trout (Salmo trutta)1995Doctoral thesis, comprehensive summary (Other academic)
  • 269. Jormalainen, Veijo
    et al.
    Wikström, Sowa A.
    Stockholm University, Faculty of Science, Department of Botany.
    Honkanen, Tuija
    Fouling mediates grazing: intertwining of resistances to multiple enemies in the brown alga Fucus vesiculosus2008In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 155, no 3, p. 559-569Article in journal (Refereed)
    Abstract [en]

    Macroalgae have to cope with multiple natural enemies, such as herbivores and epibionts. As these are harmful for the host, the host is expected to show resistance to them. Evolution of resistance is complicated by the interactions among the enemies and the genetic correlations among resistances to different enemies. Here, we explored genetic variation in resistance to epibiosis and herbivory in the brown alga Fucus vesiculosus, both under conditions where the enemies coexisted and where they were isolated. F. vesiculosus showed substantial genetic variation in the resistance to both epibiosis and grazing. Grazing pressure on the alga was generally lower in the presence than in the absence of epibiota. Furthermore, epibiosis modified the susceptibility of different algal genotypes to grazing. Resistances to epibiosis and grazing were independent when measured separately for both enemies but positively correlated when both these enemies coexisted. Thus, when the enemies coexisted, the fate of genotypes with respect to these enemies was intertwined. Genotypic correlation between phlorotannins, brown-algal phenolic secondary metabolites, and the amount of epibiota was negative, indicating that these compounds contribute to resistance to epibiosis. In addition, phlorotannins correlated also with the resistance to grazing, but this correlation disappeared when grazing occurred in the absence of epibiota. This indicates that the patterns of selection for the type of the resistance as well as for the resistance traits vary with the occurrence patterns of the enemies.

  • 270.
    Järvi, Torbjörn
    Stockholm University.
    On the evolution of inter and intra specific communication through natural and sexual selection1983Doctoral thesis, comprehensive summary (Other academic)
  • 271.
    Jürisoo, Valdek
    Stockholm University.
    Agro-ecological studies on leafhoppers (Auchenorrhyncha, Homoptera) and bugs (Heteroptera) at Ekensgård farm in the province of Hälsingland, Sweden1964Doctoral thesis, monograph (Other academic)
  • 272.
    Kaby, Ulrika
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    What limits predator detection in blue tits (Parus caeruleus): posture, task or orientation2003In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 54, no 6, p. 534-538Article in journal (Refereed)
    Abstract [en]

    To detect threats and reduce predation risk prey animals need to be alert. Early predator detection and rapid anti-predatory action increase the likelihood of survival. We investigated how foraging affects predator detection and time to take-off in blue tits (Parus caeruleus) by subjecting them to a simulated raptor attack. To investigate the impact of body posture we compared birds feeding head-down with birds feeding head-up, but could not find any effect of posture on either time to detection or time to take-off. To investigate the impact of orientation we compared birds having their side towards the attacking predator with birds having their back towards it. Predator detection, but not time to take-off, was delayed when the back was oriented towards the predator. We also investigated the impact of foraging task by comparing birds that were either not foraging, foraging on chopped mealworms, or foraging on whole ones. Foraging on chopped mealworms did not delay detection compared to nonforaging showing that foraging does not always restrict vigilance. However, detection was delayed more than 150% when the birds were foraging on whole, live mealworms, which apparently demanded much attention and handling skill. Time to take-off was affected by foraging task in the same way as detection was. We show that when studying foraging and vigilance one must include the difficulty of the foraging task and prey orientation.

  • 273.
    Kahrl, Ariel F.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Virginia, USA.
    Cox, Robert M.
    Consistent Differences in Sperm Morphology and Testis Size between Native and Introduced Populations of Three Anolis Lizard Species2017In: Journal of Herpetology, ISSN 0022-1511, E-ISSN 1937-2418, Vol. 51, no 4, p. 532-537Article in journal (Refereed)
    Abstract [en]

    Sperm morphology can be highly variable among individuals and across species, but less is known about its variation among populations. Within the past 20-80 yr, several species of Anolis lizards have been introduced to Miami, Florida, USA from different source islands in the Caribbean, thereby permitting comparisons of sperm morphology between native and introduced populations of multiple species. We collected sperm samples from native populations of Anolis sagrei (Bahamas), Anolis distichus (Dominican Republic), and Anolis cristatellus (Puerto Rico) and compared them to samples from introduced populations of each species that are now sympatric in Miami. In each of these three species, lizards from introduced populations had sperm with shorter tails and larger midpieces relative to lizards from native populations. We also measured testis size in A. distichus and A. cristatellus and found that introduced populations of each species had smaller testes for a given body size relative to their native counterparts. The consistency of these differences across species argues against random genetic drift as an explanation, suggesting instead that sperm morphology and testis size may exhibit predictable phenotypic plasticity or genetic adaptation in response to the process of introduction and/or the shared local environment in Florida. Though these population differences in male reproductive physiology and morphology may be repeatable, their underlying causes require further study.

  • 274.
    Kahsai, Lily
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Carlsson, Mikael A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Winther, Åsa M.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    Distribution of metabotropic receptors of serotonin, dopamine, GABA, glutamate, and short neuropeptide F in the central complex of Drosophila2012In: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 208, p. 11-26Article in journal (Refereed)
    Abstract [en]

    The central complex is a prominent set of midline neuropils in the insect brain, known to be a higher locomotor control center that integrates visual inputs and modulates motor outputs. It is composed of four major neuropil structures, the ellipsoid body (EB), fan-shaped body (FB), noduli (NO), and protocerebral bridge (PB). In Drosophila different types of central complex neurons have been shown to express multiple neuropeptides and neurotransmitters; however, the distribution of corresponding receptors is not known. Here, we have mapped metabotropic, G-protein–coupled receptors (GPCRs) of several neurotransmitters to neurons of the central complex. By combining immunocytochemistry with GAL4 driven green fluorescent protein, we examined the distribution patterns of six different GPCRs: two serotonin receptor subtypes (5-HT1B and 5-HT7), a dopamine receptor (DopR), the metabotropic GABAB receptor (GABABR), the metabotropic glutamate receptor (DmGluRA) and a short neuropeptide F receptor (sNPFR1). Five of the six GPCRs were mapped to different neurons in the EB (sNPFR1 was not seen). Different layers of the FB express DopR, GABABR, DmGluRA, and sNPFR1, whereas only GABABR and DmGluRA were localized to the PB. Finally, strong expression of DopR and DmGluRA was detected in the NO. In most cases the distribution patterns of the GPCRs matched the expression of markers for their respective ligands. In some nonmatching regions it is likely that other types of dopamine and serotonin receptors or ionotropic GABA and glutamate receptors are expressed. Our data suggest that chemical signaling and signal modulation are diverse and highly complex in the different compartments and circuits of the Drosophila central complex. The information provided here, on receptor distribution, will be very useful for future analysis of functional circuits in the central complex, based on targeted interference with receptor expression.

  • 275. Kaikusalo, A.
    et al.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    The Arctic Fox Population in Finnish Lapland During 30 Years, 1964-931995In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 32, no 1, p. 69-77Article in journal (Refereed)
    Abstract [en]

    We have monitored the number of arctic foxes and microtine rodents in northern Finland for 30 years. Arctic fox densities were estimated by inventories at den sites, and microtine abundance by snap trapping. Time series analyses showed that the arctic fox population fluctuated widely but always close together with the microtines in a five year cycle. However, there was no time lag in the numerical response of foxes on microtines. The strong dependence on microtines was confirmed by analyses of faecal droppings and food remains at dens. In summer time microtines consisted in average of 45% of the diet and reindeer 30%, but during winters reindeer was the most important food source with 45% compared to 15% for microtines. There was a surprising positive correlation between number of voles and reindeer carcasses, suggesting competition or alternatively an external correlation from e.g. weather. Mean litter size of the arctic fox was also highly dependent on microtine abundance but decreased during the study period despite that food resources had not changed. Further, when microtines had high densities during two consecutive years, arctic foxes only responded to the first year. A feeding experiment resulted in an increase in number of red foxes but had no or little effect on arctic foxes. So, it is difficult to single out one explanation to the decline and second year effect. Food was probably not involved and we do not know if diseases and parasites have been involved. However, both competition and predation, primarily from the red fox, may be responsible together with climatic or weather changes.

  • 276.
    Kankaala, Paula
    Stockholm University.
    On the ecology and productivity of zooplankton in the northern Baltic1984Doctoral thesis, monograph (Other academic)
  • 277.
    Kapan, Neval
    Stockholm University, Faculty of Science, Department of Zoology.
    Peptide and GABA regulation of Peptide Hormone Release in the Drosophila Brain2010Licentiate thesis, comprehensive summary (Other academic)
  • 278.
    Karlsson, Bengt
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Extended season for northern butterflies2014In: International journal of biometeorology, ISSN 0020-7128, E-ISSN 1432-1254, Vol. 58, no 5, p. 691-701Article in journal (Refereed)
    Abstract [en]

    Butterflies are like all insects temperature sensitive and a changing climate with higher temperatures might affect their phenology. Several studies have found support for earlier flight dates among the investigated species. A comparative study including 66 species of Swedish butterflies in Sweden was undertaken and the result confirms that most butterfly species will now fly earlier during the season. This is especially evident for butterflies overwintering as adults or as pupae. However, the advancement in phenology is correlated with flight date and some late season species show no advancement or have even postponed their flight dates and are now flying later in the season. The result also showed that latitude had a strong effect on the adult flight date, and the majority of the investigated species showed significantly later flights towards the north. Species flying early in the season were more affected by temperature than species flying later in the season and species overwintering in their late stages (as pupae or adults) were more influenced by temperature compared to species overwintering in their early stages (as larvae or eggs). In essence, a climate with earlier springs and longer growing seasons seems not to change the appearance patterns in a one way direction. We now see butterflies on the wings both earlier and later in the season and some consequences of these understudied and complex patterns are discussed. So far, studies have concentrated mostly on early season butterfly – plant interactions but also late season studies are needed for a better understanding of long term population consequences.

  • 279.
    Karlsson, Bengt
    Stockholm University, Faculty of Science, Department of Zoology.
    Fecundity in butterflies: adaptations and constraints1989Doctoral thesis, comprehensive summary (Other academic)
  • 280. Karlsson, Sten
    et al.
    Hagen, Merethe
    Eriksen, Line
    Hindar, Kjetil
    Jensen, Arne J.
    de Leaniz, Carlos Garcia
    Cotter, Deirdre
    Guðbergsson, Guðni
    Kahilainen, Kimmo
    Guðjónsson, Sigurður
    Romakkaniemi, Atso
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    A genetic marker for the maternal identification of Atlantic salmon x brown trout hybrids2013In: Conservation Genetics Resources, ISSN 1877-7252, E-ISSN 1877-7260, Vol. 5, no 1, p. 47-49Article in journal (Refereed)
    Abstract [en]

    Interspecific hybridization between Atlantic salmon and brown trout is well documented, but why it should vary so much among populations is not clear. Determining the maternal origin of hybrids can provide insights into the mechanisms underlying interspecific hybridization, but this information is lacking in many studies. Here we present a species-specific mitochondrial DNA marker for the identification of the maternal origin of hybrids. This marker involves only one PCR step followed by fragment analysis, can be integrated within PCR multiplexing for existing nuclear markers for hybrid identification, and is therefore faster and more cost-effective than previous methods.

  • 281.
    Kautsky, Hans
    Stockholm University, Faculty of Science, Department of Zoology.
    Factors structuring phytobenthic communities in the Baltic Sea1988Doctoral thesis, comprehensive summary (Other academic)
  • 282.
    Kautsky, Nils
    Stockholm University.
    On the role of the blue mussel, Mytilus edulis L. in the Baltic ecosystem1981Doctoral thesis, comprehensive summary (Other academic)
  • 283.
    Kautsky, Ulrik
    Stockholm University, Faculty of Science, Department of Zoology.
    Ecosystem processes in coastal areas of the Baltic sea1995Doctoral thesis, comprehensive summary (Other academic)
  • 284.
    Kazemi, Baharan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Multi-trait mimicry and the relative salience of individual traits2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, no 1818, article id 20152127Article in journal (Refereed)
    Abstract [en]

    Mimicry occurs when one species gains protection from predators by resembling an unprofitable model species. The degree of mimic-model similarity is variable in nature and is closely related to the number of traits that the mimic shares with its model. Here, we experimentally test the hypothesis that the relative salience of traits, as perceived by a predator, is an important determinant of the degree of mimic-model similarity required for successful mimicry. We manipulated the relative salience of the traits of a two-trait artificial model prey, and subsequently tested the survival of mimics of the different traits. The unrewarded model prey had two colour traits, black and blue, and the rewarded prey had two combinations of green, brown and grey shades. Blue tits were used as predators. We found that the birds perceived the black and blue traits similarly salient in one treatment, and mimic-model similarity in both traits was then required for high mimic success. In a second treatment, the blue trait was the most salient trait, and mimic-model similarity in this trait alone achieved high success. Our results thus support the idea that similar salience of model traits can explain the occurrence of multi-trait mimicry.

  • 285.
    Keehnen, Naomi L.P.
    Stockholm University, Faculty of Science, Department of Zoology.
    Immunity & the butterfly: A functional genomic study of natural variation in immunity2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Butterflies are ubiquitous and abundant, occurring in a wide variety of environments that contain diverse microbial communities with varied pathogenic pressures. These pathogens and parasites present a constant threat to organisms, and have led to the evolution of complex and intricate immune responses. Despite strong selection against immunological threats, organisms display great variation in their immune capabilities, both on the genetic and physiological level. Investigating this variation remains challenging, since differences in immune responses might arise from changes in the amount, size or performance of cells or organs. Disentangling these relative contributions is important, as the targets of selection are expected to differ, ranging from immune genes directly related to the phenotype to genes indirectly involved via cell proliferation. This thesis focuses on characterizing the immune system of the butterfly Pieris napi and investigating its remarkable variation across populations by using both phenotypic and genotypic measurements. By integrating RNA-seq with life history measurements, I found that the cost of infection and wounding in the final larval stage carries over the metamorphic boundary in P. napi (Paper II). Using population comparisons, I identified both the action and potential targets of natural selection in wild populations within their respective immune responses (Paper I, III & IV). The immune genes in P. napi show increased genetic variation compared to the rest of the genome, and microevolutionary selection dynamics act on these genes between and among populations (Paper I). I measured the cellular immune responses related to phagocytosis and melanization in common garden reared larvae originating from two allopatric populations (Spain, Sweden) (Paper III & IV). The two populations were found to differ in their blood cell composition, and overall phagocytic capability, driven by the increased phagocytic propensity of each cell type (Paper III). However, genome wide analysis of divergence between these populations found no excess genetic differentiation in genes annotated to phagocytic capacity, suggesting that our observed population differences might arise from genes affecting the activation or transdifferentiation of cells, which currently lack functional annotation. Interestingly, genes involved in glutamine metabolism, which have been linked to immune cell differentiation in mammals, did show divergence between the populations. In addition, the populations also differed in prophenoloxidase activity, a common method for quantifying immune related melanization in insects, along with the abundance of the cell-type (oenocytoids) related to this important immune function (Paper IV). Integrative analysis using both transcriptomic and genomic data revealed that the genes involved in this phenotype showed no significant differentiation between the populations. However, a gene involved with proper trafficking of melanogenic enzymes in vertebrates was found to be highly expressed and highly diverged between the two populations, providing an interesting candidate for future studies. This thesis demonstrates the advantages of integrating several genomic tools with lab experiments to quantify natural variation in the immune system of butterflies.

     

  • 286. Kelehear, Crystal
    et al.
    Webb, JK
    Hagman, Mattias
    Univ Sydney, Sch Biol Sci A08, Sydney, NSW 2006, Australia.
    Shine, Rick
    Interactions between infective helminth larvae and their anuran host2011In: Herpetologica, ISSN 0018-0831, E-ISSN 1938-5099, Vol. 67, no 4, p. 378-385Article in journal (Refereed)
    Abstract [en]

    Detailed observations on interactions between parasites and prospective hosts during the infection process can clarify (1) the routes by which parasites enter the host and (2) the ability of prospective hosts to detect, avoid, or resist potential parasites. Such information can clarify determinants of host vulnerability. Infective larvae of the nematode Rhabdias pseudosphaerocephala entered the bodies of their anuran host the Cane Toad (Rhinella marina, formerly Bufo marinus) primarily through the orbit (i.e., by crawling over the surface of the toad's eye) rather than by burrowing through the skin (believed to be the usual route of infection for rhabditid parasites). In our experimental infections, metamorph Cane Toads detected infective R. pseudosphaerocephala larvae but did not avoid them, nor did they manage to restrict rates of infective larvae penetration by using behavioral means (the toads kicked at infective larvae but failed to dislodge them). Rhabdias pseudosphaerocephala cause damage to their toad host during the process of host entry and throughout the ensuing infection. Despite the high cost of infection and the low cost of avoidance, metamorph Cane Toads seem to lack effective parasite avoidance strategies.

  • 287.
    Kempe Lagerholm, Vendela
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Department of Bioinformatics and Genetics.
    Animal movement on short and long time scales and the effect on genetic diversity in cold-adapted species2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The genetic diversity in modern species is strongly affected by contemporary gene flow between populations, which in turn is governed by individual dispersal capacities and barriers in the landscape. However, current patterns of variation have also been shaped by movement over longer time-scales, such as the successive shifts in species distributions that have occurred during past climate changes. This thesis is focused on cold-adapted species, and one parameter that has greatly influenced their current genetic diversity is how they coped with climate warming at the last glacial/interglacial transition, ca 11.7 thousand years ago. I examined this in three different small herbivore taxa; true lemmings (Lemmus), ptarmigan (Lagopus) and hares (Lepus), whose modern distributions stretch from the exposed tundra to the subarctic moorlands and taiga. In the first paper, I investigated contemporary genetic structure in the cyclic Norwegian lemming (Lemmus lemmus) and proposed that mass movements during peak years act as pulses of gene flow between mountain areas, which homogenise the gene pool over surprisingly vast geographic distances. However, when I used ancient DNA to analyse the lemmings’ ability for long-term directional movement, I found that the Ice Age populations that inhabited the former midlatitude European tundra-steppe appear to have been incapable of shifting their distribution northwards following post-glacial climate warming. Instead, the results suggest that the endemic Norwegian lemming descends from an isolated population that survived the last glacial maximum in situ in a restricted ice free refugium. In contrast to the glacial lemmings, as well the majority of previously studied mammals, the ptarmigan (L. lagopus and L. muta) and hare (L. timidus) analyses revealed a long-term genetic continuity in Europe, where the midlatitude populations were able to keep pace with the rapidly changing climate at the last glacial/interglacial transition, enabling them to shift their ranges to northern and high-alpine regions. These different outcomes might be explained by ptarmigans’ flight capability that allows a less restricted dispersal across fragmented landscapes, and that the generalist nature of mountain hares makes them less vulnerable to habitat alterations. Species distribution modelling, however, indicated that continued climate warming will make some isolated regions unsuitable in the future, thereby forcing populations to adapt the new environmental conditions in order to avoid local extinctions.

  • 288.
    Khalil, Hussein
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Pasanen Mortensen, Marianne
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The relationship between wolverine and larger predators, lynx and wolf, in a historical ecosystem context2014In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 175, no 2, p. 625-637Article in journal (Refereed)
    Abstract [en]

    Apex predators play an important role in shaping ecosystem structure. They may suppress smaller predators (mesopredators) but also subsidize scavengers via carrion provisioning. However, the importance of these interactions can change with ecosystem context. The wolverine (Gulo gulo) is a cold-adapted carnivore and facultative scavenger. It has a circumboreal distribution, where it could be either suppressed or subsidized by larger predators. In Scandinavia, the wolverine might interact with two larger predators, wolf (Canis lupus) and lynx (Lynx lynx), but human persecution decimated the populations in the nineteenth and early twentieth century. We investigated potential relationships between wolverine and the larger predators using hunting bag statistics from 15 Norwegian and Swedish counties in 1846-1922. Our best models showed a positive association between wolverine and lynx trends, taking ecological and human factors into account. There was also a positive association between year-to-year fluctuations in wolverine and wolf in the latter part of the study period. We suggest these associations could result from positive lynx-wolverine interactions through carrion provisioning, while wolves might both suppress wolverine and provide carrion with the net effect becoming positive when wolf density drops below a threshold. Wolverines could thus benefit from lynx presence and low-to-intermediate wolf densities.

  • 289. Klepsatel, Peter
    et al.
    Nagaraj Girish, Thirnahalli
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology.
    Gáliková, Martina
    Stockholm University, Faculty of Science, Department of Zoology, Functional Morphology. Slovak Academy of Sciences, Slovakia.
    Reproductive fitness of Drosophila is maximised by optimal developmental temperature2019In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 222, no 10, article id 202184Article in journal (Refereed)
    Abstract [en]

    Whether the character of developmental plasticity is adaptive or non-adaptive has often been a matter of controversy. Although thermal developmental plasticity has been studied in Drosophila for several traits, it is not entirely clear how it affects reproductive fitness. We, therefore, investigated how developmental temperature affects reproductive performance (early fecundity and egg-to-adult viability) of wild-caught Drosophila melanogaster. We have tested competing hypotheses on the character of developmental thermal plasticity using a full factorial design with three developmental and adulthood temperatures within the natural thermal range of this species. To account for potential intraspecific differences, we examined flies from tropical (India) and temperate (Slovakia) climate zones. Our results show that flies from both populations raised at intermediate developmental temperature (25°C) have comparable or higher early fecundity and fertility at all tested adulthood temperatures, while lower (17°C) or higher developmental temperatures (29°C) did not entail any advantage under the tested thermal regimes. Importantly, the superior thermal performance of flies raised at 25°C is apparent even after taking two traits positively associated with reproductive output into account – body size and ovariole number. Thus, in Drosophila melanogaster, development at a given temperature does not necessarily provide any advantage at this thermal environment in terms of reproductive fitness. Our findings strongly support the optimal developmental temperature hypothesis which claims that at different thermal environments the highest fitness is achieved when an organism is raised at its optimal developmental temperature.

  • 290.
    Klint, Thorsten
    Stockholm University.
    Factors contributing to mate selection in female mallards (Anas platyrhynchos L.): with particular emphasis on the role of the male nuptial plumage1977Doctoral thesis, comprehensive summary (Other academic)
  • 291.
    Kodandaramaiah, Ullasa
    Stockholm University, Faculty of Science, Department of Zoology.
    Effects of Wolbachia on Butterfly Life History and Ecology2011In: Advances in Medicine and Biology. Volume 16 / [ed] Leon V. Berhardt, New York: Nova Publishers , 2011Chapter in book (Other academic)
  • 292.
    Kodandaramaiah, Ullasa
    Stockholm University, Faculty of Science, Department of Zoology.
    Tectonic calibrations in molecular dating2011In: Current Zoology, Vol. 57, no 1, p. 116-124Article in journal (Refereed)
    Abstract [en]

    Molecular dating techniques require the use of calibrations, which are usually fossil or geological vicariance-based. Fossil calibrations have been criticised because they result only in minimum age estimates. Based on a historical biogeographic perspective, I suggest that vicariance-based calibrations are more dangerous. Almost all analytical methods in historical biogeography are strongly biased towards inferring vicariance, hence vicariance identified through such methods is unreliable. Other studies, especially of groups found on Gondwanan fragments, have simply assumed vicariance. Although it was previously believed that vicariance was the predominant mode of speciation, mounting evidence now indicates that speciation by dispersal is common, dominating vicariance in several groups. Moreover, the possibility of speciation having occurred before the said geological event cannot be precluded. Thus, geological calibrations can under- or overestimate times, whereas fossil calibrations always result in minimum estimates. Another major drawback of vicariant calibrations is the problem of circular reasoning when the resulting estimates are used to infer ages of biogeographic events. I argue that fossil-based dating is a superior alternative to vicariance, primarily because the strongest assumption in the latter, that speciation was caused by the said geological process, is more often than not the most tenuous. When authors prefer to use a combination of fossil and vicariant calibrations, one suggestion is to report results both with and without inclusion of the geological constraints. Relying solely on vicariant calibrations should be strictly avoided.

  • 293.
    Kodandaramaiah, Ullasa
    Stockholm University, Faculty of Science, Department of Zoology.
    The evolutionary significance of butterfly eyespots2011In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 22, no 6, p. 1264-1271Article in journal (Refereed)
    Abstract [en]

    Numerous butterflies have circular patterns called eyespots on their wings. Explanations for their functional value have until recently remained hypothetical. However, several studies in the last few years have supported long-standing hypotheses, and the current paper reviews these recent advances. Large and conspicuous eyespots are thought to be effective by being intimidating to predators and thus reducing predation. This hypothesis has received strong support in different studies. It has been shown that eyespots are intimidating because of their conspicuousness, but experimental support for the idea that eyespots are effective by mimicking vertebrate eyes is at the moment lacking. Studies have also tested the deflection hypothesis, where smaller marginal eyespots are thought to deflect attacks away from the body of the prey, increasing chances of survival with a torn wing. Despite previous negative results, recent work has shown that eyespots can indeed deflect attacks toward themselves under specific conditions. Furthermore, data show that dorsal eyespots are used by males and females as signals during courtship. How the diversity in ventral eyespot patterning has evolved remains a mystery. Future directions and further challenges in understanding the adaptive value of eyespots are discussed.

  • 294.
    Kodandaramaiah, Ullasa
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Weingartner, Elisabet
    Stockholm University, Faculty of Science, Department of Zoology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Leski, Michael
    Slove, Jessica
    Stockholm University, Faculty of Science, Department of Zoology.
    Warren, Andrew
    McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida.
    Validity of the subspecies paradigm - a case study of the nymphalid butterfly Polygonia faunusIn: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203Article in journal (Refereed)
    Abstract [en]

    Subspecies are commonly used taxonomic units to formally describe intraspecific geographic variation in morphological traits. However, the concept of subspecies is not clearly defined, and there is little agreement about what they represent in terms of evolutionary units, and whether they can be used as reliably useful units in conservation, evolutionary theory and taxonomy. Although the validity of subspecies has been tested using a multi-marker genetic approach in vertebrates, such studies have been rare in invertebrates. We here test the validity of well-characterized subspecies in the butterfly Polygonia faunus using a combination of mitochondrial sequences and eight microsatellites. We have also investigated the phylogeographic Structure of P. faunus and test whether similarities in host-plant use among populations is related to genetic similarity. Neither the nuclear nor the mitochondrial dataset corroborated subspecies groupings. We found three welldefined genetic clusters corresponding to California, Arizona and (New Mexico + Colorado). There was little structuring among the remaining populations, probably due to gene flow across populations. We found no support for the hypothesis that similarities in host use are related to genetic proximity. The results indicate that the species underwent a recent rapid expansion, probably from two glacial refugia in western North America. The mitochondrial haplotype network indicates at least two independent expansion phases into eastern North America. Ourresults clearly demonstrate that subspecies in P. faunus do not conform to the structuring of genetic variation. More studies on insects and other invertebrates are needed to understand how widespread this phenomenon is. Results in this study will be crucial in designing further experiments to understand the evolution of host plant utilization in this species.

  • 295.
    Kodandaramaiah, Ullasa
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Weingartner, Elisabet
    Stockholm University, Faculty of Science, Department of Botany.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology.
    Leski, Michael
    Slove, Jessica
    Stockholm University, Faculty of Science, Department of Zoology.
    Warren, Andrew
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology.
    Investigating concordance among genetic data, subspecies circumscriptions and hostplant use in the nymphalid butterfly polygonia faunus2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 7, p. e41058-Article in journal (Refereed)
    Abstract [en]

    Subspecies are commonly used taxonomic units to formally describe intraspecific geographic variation in morphological traits. However, the concept of subspecies is not clearly defined, and there is little agreement about what they represent in terms of evolutionary units, and whether they can be used as reliably useful units in conservation, evolutionary theory and taxonomy. We here investigate whether the morphologically well-characterized subspecies in the North American butterfly Polygonia faunus are supported by genetic data from mitochondrial sequences and eight microsatellite loci. We also investigate the phylogeographic structure of P. faunus and test whether similarities in host-plant use among populations are related to genetic similarity. Neither the nuclear nor the mitochondrial data corroborated subspecies groupings. We found three well defined genetic clusters corresponding to California, Arizona and (New Mexico+Colorado). There was little structuring among the remaining populations, probably due to gene flow across populations. We found no support for the hypothesis that similarities in host use are related to genetic proximity. The results indicate that the species underwent a recent rapid expansion, probably from two glacial refugia in western North America. The mitochondrial haplotype network indicates at least two independent expansion phases into eastern North America. Our results clearly demonstrate that subspecies in P. faunus do not conform to the structuring of genetic variation. More studies on insects and other invertebrates are needed to better understand the scope of this phenomenon. The results of this study will be crucial in designing further experiments to understand the evolution of hostplant utilization in this species.

  • 296.
    Koivisto, Ari
    Stockholm University, Faculty of Science.
    Nonselective cation channels in brown fat cells: adrenergic and NO regulation1997Doctoral thesis, comprehensive summary (Other academic)
  • 297.
    Koivisto, Sanna
    Stockholm University, Faculty of Science.
    Toxicity testing from an ecological perspective: life history and food web studies with cladocerans1996Doctoral thesis, comprehensive summary (Other academic)
  • 298.
    Kolodziejczyk, Agata
    Stockholm University, Faculty of Science, Department of Zoology.
    Chemical circuitry in the visual system of the fruitfly, Drosophila melanogaster2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Signal processing in the visual system is mediated by classic neurotransmission and neuropeptidergic modulatory pathways. In Dipteran insects, especially in the fruitfly Drosophila melanogaster, the morphology of the visual system is very well described. However neurotransmitter and neuropeptidergic circuits within the optic lobe neuropil are only partially known.

    Using several transgenic fly lines and antibodies we determined the localization of the classical neurotransmitters GABA, acetylcholine and glutamate in the visual system, and their putative targets via detecting several neurotransmitter receptors. We paid particular attention to the peripheral neuropil layer called the lamina, where the light signals are filtered, channeled and amplified (Paper I).

    We discovered four new types of efferent tangential neurons branching distally to the lamina. Among them was the first neuropeptidergic neuron (LMIo) in this region of Drosophila. The LMIo expresses myoinhibitory peptide (MIP) and has its cell body located close to the main lateral clock neurons that express the neuropeptide pigment-dispersing factor (PDF)(Paper II).

    Since in other Dipteran species PDF is expressed in processes distally to the lamina, we performed comparative anatomical studies of the MIP, PDF, Ion Transport Peptide (ITP) and serotonin (5-HT) distribution in the visual system of the flies Drosophila and Calliphora. Our data suggest that PDF signaling distal to the lamina of the blowfly might be replaced by MIP signaling in the fruitfly, while ITP and 5-HT expression is conserved in the two species (Paper III).

    Serotonin is crucial in light adaptation during the daily light-dark cycles. We analyzed putative serotonergic circuits in the lamina. We found that LMIo neurons express the inhibitory receptor 5-HT1A, while 5-HT1B and 5-HT2 are both expressed in the epithelial glia of the lamina. Another novel wide-field neuron with lamina branches expresses the excitatory serotonin receptor 5-HT7. Our studies have identified a fairly complex neuronal circuitry in the tangential plexus above the lamina. (Paper IV).

    Finally we tested circadian locomotor activity rhythms in flies with the GABAB receptor knocked down on the lateral PDF-expressing clock neurons. We observed significant changes in the activity periods and diminished strength of rhythmicity during DD suggesting a modulatory role of GABA in clock function (Paper V).

  • 299.
    Kolodziejczyk, Agata
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nichols, Charles
    Nässel, Dick
    Stockholm University, Faculty of Science, Department of Zoology.
    Distribution of serotonin receptors in the visual system of the DrosophilaManuscript (preprint) (Other academic)
  • 300.
    Kolodziejczyk, Agata
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nässel, Dick R.
    Stockholm University, Faculty of Science, Department of Zoology.
    A novel wide-field neuron with branches in the lamina of the Drosophila visual system expresses myoinhibitory peptide and may be associated with the clock2011In: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, Vol. 343, no 2, p. 357-369Article in journal (Refereed)
    Abstract [en]

    Although neuropeptides are widespread throughout the central nervous system of the fruifly Drosophila, no records exist of peptidergic neurons in the first synaptic region of the visual system, the lamina. Here, we describe a novel type of neuron that has wide-field tangential arborizations just distal to the lamina neuropil and that expresses myoinhibitory peptide (MIP). The cell bodies of these neurons, designated lateral MIP-immunoreactive optic lobe (LMIo) neurons, lie anteriorly at the base of the medulla of the optic lobe. The LMIo neurons also arborize in several layers of the medulla and in the dorso-lateral and lateral protocerebrum. Since the LMIo resemble LN(v) clock neurons, we have investigated the relationships between these two sets of neurons by combining MIP-immunolabeling with markers for two of the clock genes, viz., Cryptochrome and Timeless, or with antisera to two peptides expressed in clock neurons, viz., pigment-dispersing factor and ion transport peptide. LMIo neurons do not co-express any of these clock neuron markers. However, branches of LMIo and clock neurons overlap in several regions. Furthermore, the varicose lamina branches of LMIo neurons superimpose those of two large bilateral serotonergic neurons. The close apposition of the terminations of MIP- and serotonin-producing neurons distal to the lamina suggests that they have the same peripheral targets. Our data indicate that the LMIo neurons are not bona fide clock neurons, but they may be associated with the clock system and regulate signaling peripherally in the visual system.

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