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Molecular based assays for detection of species are a powerful tool to supplement morphological methods that may be time and labor intensive. Here we describe a sensitive TaqMan real time polymerase chain reaction assay that specifically detects the presence of Acartia tonsa in mixed plankton samples. The assay is used to find this non-native copepod in samples collected in Norwegian coastal waters.

The taiga tick, Ixodes persulcatus, has previously been limited to eastern Europe and northern Asia, but recently its range has expanded to Finland and northern Sweden. The species is of medical importance, as it, along with a string of other pathogens, may carry the Siberian and Far Eastern subtypes of tick-borne encephalitis virus. These subtypes appear to cause more severe disease, with higher fatality rates than the central European subtype. Until recently, the meadow tick, Dermacentor reticulatus, has been absent from Scandinavia, but has now been detected in Denmark, Norway and Sweden. Dermacentor reticulatus carries, along with other pathogens, Babesia canis and Rickettsia raoultii. Babesia canis causes severe and often fatal canine babesiosis, and R. raoultii may cause disease in humans. We collected 600 tick nymphs from each of 50 randomly selected sites in Denmark, southern Norway and south-eastern Sweden in August–September 2016. We tested pools of 10 nymphs in a Fluidigm real time PCR chip to screen for I. persulcatus and D. reticulatus, as well as tick-borne pathogens. Of all the 30,000 nymphs tested, none were I. persulcatus or D. reticulatus. Our results suggest that I. persulcatus is still limited to the northern parts of Sweden, and have not expanded into southern parts of Scandinavia. According to literature reports and supported by our screening results, D. reticulatus may yet only be an occasional guest in Scandinavia without established populations.

Ticks carry pathogens that can cause disease in both animals and humans, and there is a need to monitor the distribution and abundance of ticks and the pathogens they carry to pinpoint potential high risk areas for tick-borne disease transmission. In a joint Scandinavian study, we measured Ixodes ricinus instar abundance at 159 sites in southern Scandinavia in August-September, 2016, and collected 29,440 tick nymphs at 50 of these sites. We additionally measured abundance at 30 sites in August-September, 2017. We tested the 29,440 tick nymphs in pools of 10 in a Fluidigm real-time PCR chip to screen for 17 different tick-associated pathogens, 2 pathogen groups and 3 tick species. We present data on the geolocation, habitat type and instar abundance of the surveyed sites, as well as presence/absence of each pathogen in all analysed pools from the 50 collection sites and individual prevalence for each site. These data can be used alone or in combination with other data for predictive modelling and mapping of high-risk areas., Measurement(s) pathogen • Ixodida • Abundance • tick instar abundance Technology Type(s) real-time PCR • Manual Count Factor Type(s) geographic location • time of data collection Sample Characteristic - Organism Ixodes ricinus Sample Characteristic - Environment forested area • meadow ecosystem Kingdom of Denmark • Kingdom of Norway • Sweden Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12523133

Tick-borne pathogens cause diseases in animals and humans, and tick-borne disease incidence is increasing in many parts of the world. There is a need to assess the distribution of tick-borne pathogens and identify potential risk areas. We collected 29,440 tick nymphs from 50 sites in Scandinavia from August to September, 2016. We tested ticks in a real-time PCR chip, screening for 19 vector-associated pathogens. We analysed spatial patterns, mapped the prevalence of each pathogen and used machine learning algorithms and environmental variables to develop predictive prevalence models. All 50 sites had a pool prevalence of at least 33% for one or more pathogens, the most prevalent being Borrelia afzelii, B. garinii, Rickettsia helvetica, Anaplasma phagocytophilum, and Neoehrlichia mikurensis. There were large differences in pathogen prevalence between sites, but we identified only limited geographical clustering. The prevalence models performed poorly, with only models for R. helvetica and N. mikurensis having moderate predictive power (normalized RMSE from 0.74–0.75, R2 from 0.43–0.48). The poor performance of the majority of our prevalence models suggest that the used environmental and climatic variables alone do not explain pathogen prevalence patterns in Scandinavia, although previously the same variables successfully predicted spatial patterns of ticks in the same area. Tick-borne pathogens cause diseases in animals and humans, and tick-borne disease incidence is increasing in many parts of the world. There is a need to assess the distribution of tick-borne pathogens and identify potential risk areas. We collected 29,440 tick nymphs from 50 sites in Scandinavia from August to September, 2016. We tested ticks in a real-time PCR chip, screening for 19 vector-associated pathogens. We analysed spatial patterns, mapped the prevalence of each pathogen and used machine learning algorithms and environmental variables to develop predictive prevalence models. All 50 sites had a pool prevalence of at least 33% for one or more pathogens, the most prevalent being Borrelia afzelii, B. garinii, Rickettsia helvetica, Anaplasma phagocytophilum, and Neoehrlichia mikurensis. There were large differences in pathogen prevalence between sites, but we identified only limited geographical clustering. The prevalence models performed poorly, with only models for R. helvetica and N. mikurensis having moderate predictive power (normalized RMSE from 0.74–0.75, R2 from 0.43–0.48). The poor performance of the majority of our prevalence models suggest that the used environmental and climatic variables alone do not explain pathogen prevalence patterns in Scandinavia, although previously the same variables successfully predicted spatial patterns of ticks in the same area.

ticks carry pathogens that can cause disease in both animals and humans, and there is a need to monitor the distribution and abundance of ticks and the pathogens they carry to pinpoint potential high risk areas for tick-borne disease transmission. In a joint Scandinavian study, we measured Ixodes ricinus instar abundance at 159 sites in southern Scandinavia in August-September, 2016, and collected 29,440 tick nymphs at 50 of these sites. We additionally measured abundance at 30 sites in August-September, 2017. We tested the 29,440 tick nymphs in pools of 10 in a Fluidigm real-time PCR chip to screen for 17 different tick-associated pathogens, 2 pathogen groups and 3 tick species. We present data on the geolocation, habitat type and instar abundance of the surveyed sites, as well as presence/absence of each pathogen in all analysed pools from the 50 collection sites and individual prevalence for each site. these data can be used alone or in combination with other data for predictive modelling and mapping of high-risk areas. Ticks carry pathogens that can cause disease in both animals and humans, and there is a need to monitor the distribution and abundance of ticks and the pathogens they carry to pinpoint potential high risk areas for tick-borne disease transmission. In a joint Scandinavian study, we measured Ixodes ricinus instar abundance at 159 sites in southern Scandinavia in August-September, 2016, and collected 29,440 tick nymphs at 50 of these sites. We additionally measured abundance at 30 sites in August-September, 2017. We tested the 29,440 tick nymphs in pools of 10 in a Fluidigm real-time PCR chip to screen for 17 different tick-associated pathogens, 2 pathogen groups and 3 tick species. We present data on the geolocation, habitat type and instar abundance of the surveyed sites, as well as presence/absence of each pathogen in all analysed pools from the 50 collection sites and individual prevalence for each site. These data can be used alone or in combination with other data for predictive modelling and mapping of high-risk areas.

Background Tick-borne diseases have become increasingly common in recent decades and present a health problem in many parts of Europe. Control and prevention of these diseases require a better understanding of vector distribution. Aim Our aim was to create a model able to predict the distribution of Ixodes ricinus nymphs in southern Scandinavia and to assess how this relates to risk of human exposure. Methods We measured the presence of I. ricinus tick nymphs at 159 stratified random lowland forest and meadow sites in Denmark, Norway and Sweden by dragging 400 m transects from August to September 2016, representing a total distance of 63.6 km. Using climate and remote sensing environmental data and boosted regression tree modelling, we predicted the overall spatial distribution of I. ricinus nymphs in Scandinavia. To assess the potential public health impact, we combined the predicted tick distribution with human density maps to determine the proportion of people at risk. Results Our model predicted the spatial distribution of I. ricinus nymphs with a sensitivity of 91% and a specificity of 60%. Temperature was one of the main drivers in the model followed by vegetation cover. Nymphs were restricted to only 17.5% of the modelled area but, respectively, 73.5%, 67.1% and 78.8% of the human populations lived within 5 km of these areas in Denmark, Norway and Sweden. Conclusion The model suggests that increasing temperatures in the future may expand tick distribution geographically in northern Europe, but this may only affect a small additional proportion of the human population.

Background Tick-borne diseases have become increasingly common in recent decades and present a health problem in many parts of Europe. Control and prevention of these diseases require a better understanding of vector distribution. Aim Our aim was to create a model able to predict the distribution of Ixodes ricinus nymphs in southern Scandinavia and to assess how this relates to risk of human exposure. Methods We measured the presence of I. ricinus tick nymphs at 159 stratified random lowland forest and meadow sites in Denmark, Norway and Sweden by dragging 400 m transects from August to September 2016, representing a total distance of 63.6 km. Using climate and remote sensing environmental data and boosted regression tree modelling, we predicted the overall spatial distribution of I. ricinus nymphs in Scandinavia. To assess the potential public health impact, we combined the predicted tick distribution with human density maps to determine the proportion of people at risk. Results Our model predicted the spatial distribution of I. ricinus nymphs with a sensitivity of 91% and a specificity of 60%. Temperature was one of the main drivers in the model followed by vegetation cover. Nymphs were restricted to only 17.5% of the modelled area but, respectively, 73.5%, 67.1% and 78.8% of the human populations lived within 5 km of these areas in Denmark, Norway and Sweden. Conclusion The model suggests that increasing temperatures in the future may expand tick distribution geographically in northern Europe, but this may only affect a small additional proportion of the human population.

Recently, focus on tick-borne diseases has increased as ticks and their pathogens have become widespread and represent a health problem in Europe. Understanding the epidemiology of tick-borne infections requires the ability to predict and map tick abundance. We measured Ixodes ricinus abundance at 159 sites in southern Scandinavia from August-September, 2016. We used field data and environmental variables to develop predictive abundance models using machine learning algorithms, and also tested these models on 2017 data. Larva and nymph abundance models had relatively high predictive power (normalized RMSE from 0.65–0.69, R2 from 0.52–0.58) whereas adult tick models performed poorly (normalized RMSE from 0.94–0.96, R2 from 0.04–0.10). Testing the models on 2017 data produced good results with normalized RMSE values from 0.59–1.13 and R2 from 0.18–0.69. The resulting 2016 maps corresponded well with known tick abundance and distribution in Scandinavia. The models were highly influenced by temperature and vegetation, indicating that climate may be an important driver of I. ricinus distribution and abundance in Scandinavia. Despite varying results, the models predicted abundance in 2017 with high accuracy. The models are a first step towards environmentally driven tick abundance models that can assist in determining risk areas and interpreting human incidence data.

The European eel (Anguilla L.) is considered critically endangered by the IUCN Red List, and recruitment remains low. One of the challenges for the species today is migration barriers that limit their habitat. Along the Norwegian coast, like in other countries, the abundance of eels appears to decrease with distance from the sea. This pattern may be a result of factors like water temperature, water quality, competition, and habitat suitability and availability. This study aims to use environmental DNA (eDNA) analysis to investigate the potential relationship between migration barriers and the decreasing occurrence of eels in distance from the sea by the coast of southern Norway. Sixty locations with potential migration barriers are investigated by collecting water samples upstream and downstream from each construction before eDNA from each sample is isolated and analyzed by real-time PCR with specific primers and probes matching A. anguilla. The results reveal that the probability of detecting eel eDNA decreases significantly with number of hydroelectric power stations and their associated basins, even when the effect of distance to sea is accounted for. In addition, there is a clear border at which eel eDNA could no longer be detected upstream of the major watercourses. Therefore, it is likely that the migration of eels is prohibited by these constructions, which seem to constitute a much greater challenge than every other type of potential migration barrier investigated in this study.

Background Oxidative stress is evident from an early stage in chronic kidney disease (CKD). Therefore, we investigated redox biomarkers in polycystic kidney disease (ADPKD) and IgA nephropathy (IGAN). Methods This is a case-control study with three groups: ADPKD (n = 54), IGAN (n = 58) and healthy controls (n = 86). The major plasma aminothiols with their redox species were examined: homocysteine (Hcy), cysteinglycine (CG), cysteine (Cys) and glutathione (GSH). The redox ratio was the ratio of reduced free and oxidized aminothiols in plasma. We investigated malonedialdehyde (MDA) and advanced oxidation protein products (AOPP), and ten single nucleotide polymorphisms of antioxidant enzymes. Results Patients had elevated oxidized free Hcy and Cys with associated low redox ratios – most pronounced in IGAN. Patients with IGAN had elevated AOPP and possibly MDA. Oxidized free Hcy and Cys with redox ratios were correlated to AOPP, MDA and proteinuria. Furthermore, there was an independent relationship to parathyroid hormone (PTH). IGAN had an elevated frequency of Val16Ala SNP rs4880, which influence the function of mitochondrial superoxide dismutase 2 (p = 0.03). Conclusions Patients with ADPKD and IGAN have evidence of oxidative stress from stage 1 to 4 – most pronounced in IGAN. In patients, aminothiol redox biomarkers were correlated to AOPP, proteinuria and PTH, which are known prognostic markers in CKD. It may be possible that oxidative stress influences PTH dysregulation in CKD. The association between IGAN and the redox related variant allele rs4880(C) might indicate a new susceptibility locus for IGAN, but this needs verification.

As part of a larger survey, ears from 18 roe deer (Capreolus capreolus) and 52 moose (Alces alces) shot in the 2 southernmost counties in Norway were collected and examined for Ixodes ricinus ticks. Seventy-two adult ticks, 595 nymphs, and 267 larvae from the roe deer, and 182 adult ticks, 433 nymphs, and 70 larvae from the moose were investigated for infection with Borrelia burgdorferi sensu lato (s.l.). The results showed the presence of B. burgdorferi s.l. DNA in 2.9% of the nymphs collected from roe deer and in 4.4% of the nymphs and 6.0% of the adults collected from moose. The spirochetes were not detected in adult ticks from roe deer, or in larvae feeding on roe deer or moose. In comparison, the mean infection prevalences in questing I. ricinus collected from the same geographical area were 0.5% infection in larvae, 24.5% in nymphs, and 26.9% in adults. The most prevalent B. burgdorferi genospecies identified in ticks collected from roe deer was B. afzelii (76.5%), followed by B. garinii (17.6%), and B. burgdorferi sensu stricto (5.9%). Only B. afzelii (76.7%) and B. garinii (23.3%) were detected in ticks collected from moose. The present study indicates a lower prevalence of B. burgdorferi infection in I. ricinus ticks feeding on roe deer and moose compared to questing ticks. This is the first study to report B. burgdorferi s.l. prevalence in ticks removed from cervids in Norway.

The mountain hare (Lepus timidus) population in southern Norway appears to be in decline. Necropsy and laboratory examinations of 36 hares found dead or diseased during 2007-2009 in Vest- and Aust-Agder counties showed that disease and deaths were attributed to multiple causes, with no specific etiology emerging as a cause for population decline. To investigate whether Borrelia burgdorferi sensu lato (s.l.) infection is associated with mortality in mountain hares, tissues and ticks collected from hares were investigated for infection with the spirochete. Borrelia burgdorferi s.l. DNA was not detected in samples from internal organs, whereas Borrelia afzelii, B. burgdorferi sensu stricto (s.s.), and the not-yet-defined Borrelia sp. SV1 were found in skin samples from hares and in adult and nymphal Ixodes ricinus feeding on hares. Only B. burgdorferi s.s. and Borrelia sp. SV1 were detected in larvae feeding on hares. Our results indicate that disseminated Borrelia infection in hares rarely occurs and, presumably, does not play a central role in the suspected population decline. The results also suggest that the mountain hare to some degree functions as a transmission host for B. burgdorferi s.s. and Borrelia sp. SV1.

This paper describes the finding of genes displaying differential expression in Nile tilapia (Oreochromis niloticus) adapted to saltwater and discusses their potential involvement in saltwater tolerance. The availability of fresh water is severely limited in many countries; therefore, the use of brackish-water areas may present an opportunity to expand the tilapia aquaculture industry. Increased knowledge of genes involved in saltwater tolerance will facilitate selection for this trait in tilapia. A set of fish from four different families of Nile tilapia was divided into two freshwater containers, the different families equally represented in the two experimental groups, and salinity was gradually increased in one of them. A differential expression study identified a number of genes expressed differently in saltwater and fresh water. Based on these expression analyses and on a judgement of potential candidate genes probably to be involved in adaptation to changes in salinity, four genes were selected and their levels of expression further analysed by real-time polymerase chain reaction. The selected genes beta haemoglobin, Ca 2þ transporting plasma membrane ATPase, pro-opiomelanocortin and beta-actin showed changes in expression. The genes were mapped and assigned to an already existing, high-resolution linkage map.

From April to October 2007, host-seeking Ixodes ricinus ticks were collected from four locations in southern Norway; Farsund, Mandal, Sogne and Tromoy, respectively. Larvae (n=210), nymphs (n=1130) and adults (n=449) were investigated for infection with Borrelia miyamotoi by real-time polymerase chain reaction (PCR) amplification of part of the 16S rRNA gene. Results were verified by direct sequencing of the PCR amplicon generated from the rrs (16S)-rrl (23S) intergenetic spacer. B. miyamotoi was detected at all sites and throughout the period of questing activity, with infection prevalence (≤1.26%) similar to what has been seen in other European countries. Detection of the relapsing fever spirochete at all locations indicates a wide distribution in southern Norway. This is the first report of B. miyamotoi prevalence in ticks collected from Norway. As not much is known about the spatiotemporal dynamics of this relatively recently discovered pathogen, the conclusions of this study significantly add to the knowledge regarding B. miyamotoi in this region.

Wild and farmed stocks of Atlantic salmon were genotyped, using 16 microsatellites and 26 SNPs. Some population parameters were estimated, as well as the power of these markers to assign single individuals to their sampling population. The efficiencies of the marker sets for parentage testing in farmed populations were also estimated. A total of five wild river strains and two farmed stocks were genotyped. The average heterozygosity was 0.41 and 0.51 for the SNPs and microsatellites, respectively. The microsatellite set displayed an average allele number of 3.8 within populations and 7.9 per locus. The calculated exclusion probabilities of the parentage analyses based on each of the two marker sets were better than 99.9%, which demonstrates their robustness in parentage testing. Genetic assignment analysis allocated 95.8% of the individuals to the sampling population. Neighbour-joining phylograms based on individual genotypes from both marker sets tended to cluster individuals according to their sampling population. Some potential strain-specific alleles were discovered for the microsatellites. Such alleles may have a potential additional value of population identification. The SNP collection showed nearly as good results as the microsatellites in this study and improved high throughput typing methods for SNP detection suggest that they can be a good alternative to microsatellites for future typing.

We constructed a second-generation linkage map of tilapia from the F2 progeny of an interspecific cross between Oreochromis niloticus and Oreochromis aureus. The map reported here contains 525 microsatellite and 21 gene-based markers. It spans 1311 cM in 24 linkage groups, for an average marker spacing of 2.4 cM. We detected associations of sex and red color with markers on linkage group 3. This map will enable mapping and selective breeding of quantitative traits important to the economic culture of tilapia as a food fish and will contribute to the study of closely related cichlids that have undergone explosive adaptive radiation in the lakes of East Africa.

Objectives A number of studies have explored the effects of dietary nitrate on human health. Nitrate in the blood can be recycled to nitric oxide, which is an essential mediator involved in many important biochemical mechanisms. Nitric oxide is also formed in the body from l -arginine by nitric oxide synthase. The aim of this study was to investigate whether genetic polymorphisms in endothelial nitric oxide synthase (eNOS) and genes involved in folate metabolism affect the concentration of serum nitrate, serum folate, and plasma total homocysteine in healthy individuals after folic acid supplementation. Methods In a randomized double-blind, crossover study, participants were given either folic acid 800 μg/d (n = 52) or placebo (n = 51) for 2 wk. Wash-out period was 2 wk. Fasting blood samples were collected, DNA was extracted by salting-out method and the polymorphisms in eNOS synthase and folate genes were genotyped by polymerase chain reaction methods. Measurement of serum nitrate and plasma total homocysteine (p-tHcy) concentration was done by high-performance liquid chromatography. Results The concentration of serum nitrate did not change in individuals after folic acid supplements (trial 1); however, the concentration of serum nitrate increased in the same individuals after placebo (P = 0.01) (trial 2). The individuals with three polymorphisms in eNOS gene had increased concentration of serum folate and decreased concentration of p-tHcy after folic acid supplementation. Among the seven polymorphisms tested in folate metabolizing genes, serum nitrate concentration was significantly decreased only in DHFR del 19 gene variant. A significant difference in the concentration of serum nitrate was detected among individuals with MTHFR C > T677 polymorphisms. Conclusions Polymorphisms in eNOS and folate genes affect the concentration of serum folate and p-tHcy but do not have any effect on the concentration of NO3 in healthy individuals after folic acid supplementation. 2014 Elsevier Inc. All rights reserved.

A genetic marker map of Atlantic salmon would facilitate the identification of loci influencing economically important traits. In the present paper we describe five new Atlantic salmon microsatellites. Segregation studies and linkage analysis of these and previously published microsatellites were carried out in pedigrees consisting of diploid dams and haploid gynogenetic offspring. We confirm earlier reports that salmon microsatellites tend to have a higher number of repeat units than those of mammals. Linkage analysis revealed that three microsatellites belong to a linkage group spanning approximately 50 cM of the genome, whereas the remaining 10 markers seem to be unlinked.

Little is known about the molecular genetic changes in malignant peripheral nerve sheath tumors (MPNST). Inactivation of the TP53 gene in l7p has been reported in a few tumors. The MPNST is one of the manifestations of neurofibromatosis 1 (NF1), suggesting that the NF1 gene in 17q might be important. We present a study of 15 neurofibromas and MPNST from nine individuals. Seven patients had NF1 and six of these developed MPNST. Genetic alterations at nine polymorphic loci on chromosome 17 were examined. Allelic imbalance was detected only in the malignant tumors from NF1 patients (4/6). Complete loss of heterozygosity of 17q loci was found in three of these tumors, all including loci within the NF1 gene. Two of the malignant tumors also showed deletions on 17p. No mutations were detected within exon 5-8 of the TP53 in any of the MPNST, and none of them were TP53 protein-positive using immunostaining with mono- and polyclonal antibodies against TP53. The numbers of chromosome 17 present in each tumor were evaluated by use of fluorescence in situ hybridization (FISH) on interphase nuclei with a centromere-specific probe. A deviation from the disomic status of chromosome 17 was observed in two of the MPNSTmore » from NF1 patients. These results support the hypothesis of inactivation of both NF1 gene alleles during development of MPNST in patients with NF1. In contrast to other reports, we did not find evidence for a homozygous mutated condition of the TP53 gene in the same tumors. Finally, FISH analysis was in accordance with the DNA analysis in the deduction of the numbers of chromosome 17 in these tumors. 29 refs., 3 figs., 2 tabs.« less

So far, fish maps, merely based on linkage groups of biochemical markers, have to some extent been hindered by lack of all the mapping methodologies currently used in higher vertebrates. In salmonids and xiphophorus species, though, more than 50 and 80 loci have been assigned to 18 and 20 linkage groups, respectively. However, the exploitation of comparative mapping data together with natural fish features as high reproductive capacity, interspecific fertile hybrids and parthenogenesis, and the currently growing array of DNA‐markers and techniques, will speed up the fish map development considerably. We have taken advantage of this by basing our linkage analysis on a material consisting of Atlantic salmon dams and their haploid gynogenetic offspring (female counterpart of sperm typing). Our mapping landmarks are polymorphic microsatellites and genes within the MHC region. Tentative microsatellite based linkage groups have been defined together with a prelimeinary physical map of the MHC region. I...

Inspired by the recently introduced single sperm typing and by turning to account natural features of fish reproduction and development (e.g. parthenogenesis), we have established an efficient strategy in Atlantic salmon (Salmo salar L.) to assist classical linkage analysis. By haploid gynogenesis we have generated an average of 500 haploid female fry from each of 20 unrelated normal diploid dams. Eggs have been “pseudofertilized” with irradiated sperm giving rise to haploid individuals, representing a single maternal meiotic event with no sperm genome contribution. In genetic analysis terms this strategy represents the female counterpart of sperm typing but offers some advantages: no individual sorting problem, repeated tests are possible on the same individual (considerable amount of cells and DNA), not entirely dependent on PCR (although preferable to save material) and markers that can be mapped are not restricted to DNA. Like for single sperm typing, the almost unlimited material enables us ...

From April to October 2007, host-seeking Ixodes ricinus ticks were collected from 4 locations in southern Norway: Farsund, Mandal, Sogne and Tromoy. Two hundred and ten larvae, 1130 nymphs and 449 adults were investigated for infection with Borrelia burgdorferi sensu lato (s.l.) by real-time polymerase chain reaction (PCR) amplification of the 16S rRNA gene. The total percentage of B. burgdorferi s.l. in nymphal and adult ticks was determined to be 31.3% in Farsund, 25.2% in Mandal, 22.3% in Sogne and 22.1% in Tromoy. Larvae were pooled in groups of 10 before analysis, and Borrelia infection was detected in 1 of the 21 larvae pools. B. burgdorferi s.l. were genotyped by melting curve analysis after real-time PCR amplification of the hbb gene, or by direct sequencing of the PCR amplicon generated from the rrs (16S)-rrl (23S) intergenetic spacer. The most prevalent B. burgdorferi genospecies identified were B. afzelii (61.6%), followed by B. garinii (23.4%) and B. burgdorferi sensu stricto (10.6%). B. valaisiana (4.5%) was identified in Norwegian ticks for the first time. Mixed infections were observed in 0.3% of the infected ticks. A higher prevalence of B. burgdorferi s.l. was found in the present study than what has been reported in previous Nordic studies.

We constructed a second-generation linkage map of tilapia from the F(2) progeny of an interspecific cross between Oreochromis niloticus and Oreochromis aureus. The map reported here contains 525 microsatellite and 21 gene-based markers. It spans 1311 cM in 24 linkage groups, for an average marker spacing of 2.4 cM. We detected associations of sex and red color with markers on linkage group 3. This map will enable mapping and selective breeding of quantitative traits important to the economic culture of tilapia as a food fish and will contribute to the study of closely related cichlids that have undergone explosive adaptive radiation in the lakes of East Africa.

Anthropogenic activities are putting marine and freshwater ecosystems under increasing pressure and global climate change is causing transformations in ecosystems and food chains worldwide. Invasive species pose one of the greatest threats to natural diversity and the endemic species essential for ecosystem balance. In November 2021, Gillsvann in Kristiansand, Norway, was treated with rotenone with the aim of eradicating the invasive species Northern pike (Esox lucius) from the lake. The effectiveness of the treatment was monitored using environmental DNA (eDNA) analysis. The primary objective was to investigate the presence of Northern pike eDNA in the lake from November 2021 (after the treatment) to November 2022. Monthly water samples were collected from 14 different locations in Gillsvann and analyzed using real-time PCR with species-specific eDNA. The findings of the study revealed that the presence of Northern pike eDNA was observed consistently each month up until the month of April in the year 2022. However, from the month of May until November in the same year, there was no detection of Northern pike eDNA, suggesting that the species may have been successfully eliminated from the lake. The second objective was to analyze eDNA of three-spined stickleback (Gasterosteus aculeatus) to assess the re-establishment of endemic species. The results suggest that three-spined stickleback likely re-invaded the lake following the rotenone treatment, with eDNA levels returning to pre-treatment levels by June 2022. This indicates that the species has successfully re-established in Gillsvann. Overall, this study demonstrates the potential effectiveness of rotenone treatment for eradicating invasive species and the utility of eDNA analysis for monitoring the possible success of eradication efforts and re-establishment of native species.