| 71. |
- Carlsbecker, Annelie, et al.
(författare)
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The MADS-box gene DAL1 is a potential mediator of the juvenile-to-adult transition in Norway spruce (Picea abies)
- 2004
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Ingår i: The Plant Journal. ; 40:4, s. 546-557
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Tidskriftsartikel (refereegranskat)abstract
- Progression through the plant life cycle involves changes in many essential features, most notably in the capacity to reproduce. The transition from juvenile vegetative and non-reproductive to an adult reproductive phase is gradual and can take many years; in the conifer Norway spruce, Picea abiea, typically 20-25 years. We present a detailed analysis of the activities of three regulatory genes with potential roles in the transition in Norway spruce: DAL1, a MADS-box gene related to the AGL6 group of genes from angiosperms, and the two LEAFY-related genes PaLFY and PaNLY. DAL1 activity is initiated in the shoots of juvenile trees at an age of 3-5 years, and then increases with age, whereas both LFY genes are active throughout the juvenile phase. The activity of DAL1 further shows a spatial pattern along the stem of the tree that parallels a similar gradient in physiolpoical and morphological features associated with maturation to the adult phase. Constitutive expression of DAL1 in transgenic Arabidopsis plants caused a dramatic attenuation of both juvenile and adult growth phases;flowers forming immediately after the embryogenic phase of development in severely affected plants. Taken together, our resulsts support the notion that DAL1 may have a regulatory role in the juvenile-to-adult transition in Norway spruce.
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| 72. |
- Cattaneo, Alberto Maria, et al.
(författare)
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TRPA5, an Ankyrin Subfamily Insect TRP Channel, is Expressed in Antennae of Cydia pomonella (Lepidoptera : Tortricidae) in Multiple Splice Variants
- 2016
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Ingår i: Journal of Insect Science. - : Oxford University Press (OUP). - 1536-2442. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Transient receptor potential (TRP) channels are an ancient family of cation channels, working as metabotropic triggers, which respond to physical and chemical environmental cues. Perception of chemical signals mediate reproductive behaviors and is therefore an important target for sustainable management tactics against the codling moth Cydia pomonella L. (Lepidoptera: Tortricidae). However, olfactory behavior strongly depends on diel periodicity and correlation of chemical with physical cues, like temperature, and physical cues thus essentially contribute to the generation of behavioral response. From an antennal transcriptome generated by next generation sequencing, we characterized five candidate TRPs in the codling moth. The coding DNA sequence of one of these was extended to full length, and phylogenetic investigation revealed it to be orthologous of the TRPA5 genes, reported in several insect genomes as members of the insect TRPA group with unknown function but closely related to the thermal sensor pyrexia. Reverse transcription PCR revealed the existence of five alternate splice forms of CpTRPA5. Identification of a novel TRPA and its splice forms in codling moth antennae open for investigation of their possible sensory roles and implications in behavioral responses related to olfaction.
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| 73. |
- Ekelund Ugge, Gustaf Magnus Oskar, 1990-
(författare)
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Transcriptional biomarkers of toxicity – powerful tools or random noise? : An applied perspective from studies on bivalves
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aquatic organisms are constantly at risk of being exposed to potentially harmful chemical compounds of natural or anthropogenic origin. Biological life can for instance respond to chemical stressors by changes in gene expression, and thus, certain gene transcripts can potentially function as biomarkers, i.e. early warnings, of toxicity and chemical stress. A major challenge for biomarker application is the extrapolation of transcriptional data to potential effects at the organism level or above. Importantly, successful biomarker use also requires basal understanding of how to distinguish actual responses from background noise. The aim of this thesis is, based on response magnitude and variation, to evaluate the biomarker potential in a set of putative transcriptional biomarkers of general toxicity and chemical stress.Specifically, I addressed a selection of six transcripts involved in cytoprotection and oxidative stress: catalase (cat), glutathione-S-transferase (gst), heat shock proteins 70 and 90 (hsp70, hsp90), metallothionein (mt) and superoxide dismutase (sod). Moreover, I used metal exposures to serve as a proxy for general chemical stress, and due to their ecological relevance and nature as sedentary filter-feeders, I used bivalves as study organisms.In a series of experiments, I tested transcriptional responses in the freshwater duck mussel, Anodonta anatina, exposed to copper or an industrial wastewater effluent, to address response robustness and sensitivity, and potential controlled (e.g. exposure concentration) and random (e.g. gravidness) sources of variation. In addition, I performed a systematic review and meta-analysis on transcriptional responses in metal exposed bivalves to (1) evaluate what responses to expect from arbitrary metal exposures, (2) assess the influence from metal concentration (expressed as toxic unit), exposure time and analyzed tissue, and (3) address potential impacts from publication bias in the scientific literature.Response magnitudes were generally small in relationship to the observed variation, both for A. anatina and bivalves in general. The expected response to an arbitrary metal exposure would generally be close to zero, based on both experimental observations and on the estimated impact from publication bias. Although many of the transcripts demonstrated concentration-response relationships, large background noise might in practice obscure the small responses even at relatively high exposures. As demonstrated in A. anatina under copper exposure, this can be the case already for single species under high resolution exposures to single pollutants. As demonstrated by the meta-regression, this problem can only be expected to increase further upon extrapolation between different species and exposure scenarios, due to increasing heterogeneity and random variation. Similar patterns can also be expected for time-dependent response variation, although the meta-regression revealed a general trend of slightly increasing response magnitude with increasing exposure times.In A. anatina, gravidness was identified as a source of random variability that can potentially affect the baseline of most assessed biomarkers, particularly when quantified in gills. Response magnitudes and variability in this species were generally similar for selected transcripts as for two biochemical biomarkers included for comparison (AChE, GST), suggesting that the transcripts might not capture early warnings more efficiently than other molecular endpoints that are more toxicologically relevant. Overall, high concentrations and long exposure durations presumably increase the likelihood of a detectable transcriptional response, but not to an extent that justifies universal application as biomarkers of general toxicity and chemical stress. Consequently, without a strictly defined and validated application, this approach on its own appears unlikely to be successful for future environmental risk assessment and monitoring. Ultimately, efficient use of transcriptional biomarkers might require additional implementation of complementary approaches offered by current molecular techniques.
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| 74. |
- Emami, S. Noushin, et al.
(författare)
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A key malaria metabolite modulates vector blood seeking, feeding, and susceptibility to infection
- 2017
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 355:6329
-
Tidskriftsartikel (refereegranskat)abstract
- Malaria infection renders humans more attractive to Anopheles gambiae sensu lato mosquitoes than uninfected people. The mechanisms remain unknown. We found that an isoprenoid precursor produced by Plasmodium falciparum, (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), affects A. gambiae s. l. blood meal seeking and feeding behaviors as well as susceptibility to infection. HMBPP acts indirectly by triggering human red blood cells to increase the release of CO2, aldehydes, and monoterpenes, which together enhance vector attraction and stimulate vector feeding. When offered in a blood meal, HMBPP modulates neural, antimalarial, and oogenic gene transcription without affecting mosquito survival or fecundity; in a P. falciparum-infected blood meal, sporogony is increased.
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| 75. |
- Ericson, Y, et al.
(författare)
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Faktablad från Integrerad kustfiskövervakning: Fjällbacka (Västerhavet) 1989-2015
- 2016
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Ingår i: Faktablad 2016 från Inst för Akvatiska resurser, SLU. ; :2016:1
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Faktabladet presenterar resultat och bedömningar från den integrerade kustfiskövervakningen i Fjällbacka-området 1989-2015. Övervakningen visar att situationen för tånglake i Fjällbacka är ansträngd. En återhämtning kan dock skönjas de allra sista åren. Tidigare vikande fångster och en försämring av tånglakens hälsotillstånd samt yngelstatus antyder att arten påverkas negativt av omgivningsfaktorer såsom den ökande vattentemperaturen, syrenivåer och exponering för kemikalier.
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| 76. |
- Ericson, Y, et al.
(författare)
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Faktablad från Integrerad kustfiskövervakning: Holmön (Bottniska viken) 1989-2015.
- 2016
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Ingår i: Faktablad 2016 från Inst för Akvatiska Resurser, SLU. ; :2016: 2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Faktabladet presenterar resultat och bedömningar från den integrerade kustfiskövervakningen vid Holmön under tidsperioden 1989-2015. Övervakningen visar för varje år ett alltmer påverkat hälsotillstånd hos abborre trots att de flesta analyserade metaller och organiska miljögifter visar nedåtgående trender eller oförändrade halter. Den tydliga och successiva påverkan som ses på hälsotillståndet på individnivå har ännu inte resulterat i några påtagliga förändringar på bestånds- och samhällsnivå.
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| 77. |
- Ericson, Y, et al.
(författare)
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Faktablad från Integrerad kustfiskövervakning: Kvädöfjärden (Egentliga Östersjön) 1989-2015.
- 2016
-
Ingår i: Faktablad 2016 från Inst för Akvatiska Resurser, SLU. ; :2016:3
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Faktabladet presenterar resultat och bedömningar från den integrerade kustfiskövervakningen i Kvädöfjärden under tidsperioden 1989-2015. Kustfiskövervakningen visar på minskande karpfiskbestånd, minskad totalfångst av fisk och ett påverkat hälsotillstånd hos abborre och tånglake, samtidigt som de flesta analyserade miljögifter visar nedåtgående trender eller oförändrade halter.
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| 78. |
- Ericson, Y, et al.
(författare)
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Faktablad från Integrerad kustfiskövervakning: Torhamn (södra Egentliga Östersjön) 2002-2015
- 2016
-
Ingår i: Faktablad 2016 från Inst för Akvatiska resurser, SLU. ; :2016:4
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Faktabladet presenterar resultat och bedömningar från den integrerade kustfiskövervakningen i Torhamnsområdet under tidsperioden 2002-2015. Resultaten från tretton års undersökningar visar en alltmer tydlig påverkan på hälsotillståndet hos abborre liknande den som observeras hos abborre och tånglake i andra kustreferensområden. Denna tydliga och successiva påverkan som ses på abborrens hälsa på individnivå har ännu inte resulterat i några påtagliga förändringar på bestånds- eller samhällsnivå.
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| 79. |
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| 80. |
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