Negative density-dependent emigration of males in an increasing red deer population

In species with polygynous mating systems, females are regarded as food-limited, while males are limited by access to mates. When local density increases, forage availability declines, while mate access for males may increase due to an increasingly female-biased sex ratio. Density dependence in emigration rates may consequently differ between sexes. Here, we investigate emigration using mark-recovery data from 468 young red deer Cervus elaphus marked in Snillfjord, Norway over a 20-year period when the population size has increased sixfold. We demonstrate a strong negative density-dependent emigration rate in males, while female emigration rates were lower and independent of density. Emigrating males leaving the natal range settled in areas with lower density than expected by chance. Dispersing males moved 42 per cent longer at high density in 1997 (37 km) than at low density in 1977 (26 km), possibly caused by increasing saturation of deer in areas surrounding the marking sites. Our study highlights that pattern of density dependence in dispersal rates may differ markedly between sexes in highly polygynous species. Contrasting patterns reported in small-scale studies are suggestive that spatial scale of density variation may affect the pattern of temporal density dependence in emigration rates and distances.     

End Stage Renal Disease Predicts Increased Risk of Death in First Degree Relatives in the Norwegian Population

BackgroundIncreased risk of end stage renal disease (ESRD) and death in Norwegian living kidney donors has been reported, most of the donors were related to the recipient. The present study investigates risk of death in first degree relatives of ESRD patients.MethodsThe Norwegian Population Registry, The Norwegian Cause of Death Registry and the Norwegian Renal Registry were linked. All citizens born in Norway, alive in 1960 and with at least one registered first degree relative were included; individuals who died during the first year of life were excluded. A cohort-design was used, ESRD in a first degree relative was the main exposure variable and death and causes of death were the main outcome variables. Cox regression statistics were used to investigate mortality risks.Results5 130 600 individuals were included, 27 508 had at least one first degree relative with ESRD. 828 022 died during follow-up, of whom 4105 had a first degree relative with ESRD. Adjusted hazard ratio (aHR) for death was 1.13 (1.09–1.16) in individuals with a relative with ESRD compared to those without a relative with ESRD. Excluding known hereditary renal disease, aHR decreased to 1.12 (1.09–1.15). Cardiovascular death aHR was 1.15 (1.10–1.21), of which cerebrovascular death 1.34 (1.22–1.50). aHR for death due to non-hereditary renal/ureteric disease was 2.29 (1.81–2.91) with renal failure 1.80 (1.26–2.56) and glomerular disease 5.69 (3.88–8.34) as main contributors. Diabetes mellitus death aHR was 1.68 (1.35–2.10). Absolute mortality risks increased most for the oldest cohorts with excess mortality of 148 per 100.000 person years for the cohort born 1920–39 and 218 for the cohort born 1900–1919.ConclusionsESRD in first degree relatives was associated with increased hazard ratio for death. Death due to cardiovascular disease, renal disease and diabetes mellitus increased the most.     

Occurrence of leeches (Hirudinea, Piscicolidae) on some marine fishes in Norway

Marine fish from several locations along the west coast of Norway were examined for leeches. Seven leech species were detected, Calliobdella nodulifera (Malm, 1863) from codfish, flatfish and a ray, Calliobdella lophii van Beneden & Hesse, 1863 from Lophius piscatorius L., Platybdella anarrhichae (Diesing, 1859) on Anarhichas lupus L., Platybdella quadrioculata Malm, 1863 on Symphodus melops (L.), Oceanobdella sp. on Zeugopterus punctatus (Bloch), Malmiana brunnea (Johansson, 1896) on Myoxocephalus scorpius (L.) and Malmiana bubali Srivastava, 1966 on Taurulus bubalis (Euphrasen). Calliobdella nodulifera infected unrelated hosts (euryxenic); the others appeared to be host specialists (oio- or stenoxenic). Details on the occurrence of Calliobdella nodulifera on Enchelyopus cimbrius (L.) during 1 year are given, which together with other observations suggest that its life cycle exceeds a year. A brief account on the morphology of “Platybdella” quadrioculata is provided, justifying its transfer to the genus Oceanobdella Caballero, 1956 as O. quadrioculata comb. nov. With the new additions, the Norwegian marine piscicolid fauna contain 12 species. At least ten additional species, known from adjoining areas, also probably occur along the Norwegian coast.     

Structural,Biochemical, and Computational Characterization of the Glycoside Hydrolase Family 7 Cellobiohydrolase of the Tree-killing Fungus Heterobasidion irregulare

Root rot fungi of the Heterobasidion annosum complex are the most damaging pathogens in temperate forests, and the recently sequenced Heterobasidion irregulare genome revealed over 280 carbohydrate-active enzymes. Here, H. irregulare was grown on biomass, and the most abundant protein in the culture filtrate was identified as the only family 7 glycoside hydrolase in the genome, which consists of a single catalytic domain, lacking a linker and carbohydrate-binding module. The enzyme, HirCel7A, was characterized biochemically to determine the optimal conditions for activity. HirCel7A was crystallized and the structure, refined at 1.7 Å resolution, confirms that HirCel7A is a cellobiohydrolase rather than an endoglucanase, with a cellulose-binding tunnel that is more closed than Phanerochaete chrysosporium Cel7D and more open than Hypocrea jecorina Cel7A, suggesting intermediate enzyme properties. Molecular simulations were conducted to ascertain differences in enzyme-ligand interactions, ligand solvation, and loop flexibility between the family 7 glycoside hydrolase cellobiohydrolases from H. irregulare, H. jecorina, and P. chrysosporium. The structural comparisons and simulations suggest significant differences in enzyme-ligand interactions at the tunnel entrance in the −7 to −4 binding sites and suggest that a tyrosine residue at the tunnel entrance of HirCel7A may serve as an additional ligand-binding site. Additionally, the loops over the active site in H. jecorina Cel7A are more closed than loops in the other two enzymes, which has implications for the degree of processivity, endo-initiation, and substrate dissociation. Overall, this study highlights molecular level features important to understanding this biologically and industrially important family of glycoside hydrolases.     

Molecular Genetic Analysis of Stomach Contents Reveals Wild Atlantic Cod Feeding on Piscine Reovirus (PRV) Infected Atlantic Salmon Originating from a Commercial Fish Farm

In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen''s observations. These analyses provide new insights into interactions between domesticated and wild fish.     

ClusTrack: Feature Extraction and Similarity Measures for Clustering of Genome-Wide Data Sets

Clustering is a popular technique for explorative analysis of data, as it can reveal subgroupings and similarities between data in an unsupervised manner. While clustering is routinely applied to gene expression data, there is a lack of appropriate general methodology for clustering of sequence-level genomic and epigenomic data, e.g. ChIP-based data. We here introduce a general methodology for clustering data sets of coordinates relative to a genome assembly, i.e. genomic tracks. By defining appropriate feature extraction approaches and similarity measures, we allow biologically meaningful clustering to be performed for genomic tracks using standard clustering algorithms. An implementation of the methodology is provided through a tool, ClusTrack, which allows fine-tuned clustering analyses to be specified through a web-based interface. We apply our methods to the clustering of occupancy of the H3K4me1 histone modification in samples from a range of different cell types. The majority of samples form meaningful subclusters, confirming that the definitions of features and similarity capture biological, rather than technical, variation between the genomic tracks. Input data and results are available, and can be reproduced, through a Galaxy Pages document at http://hyperbrowser.uio.no/hb/u/hb-superuser/p/clustrack. The clustering functionality is available as a Galaxy tool, under the menu option "Specialized analyzis of tracks", and the submenu option "Cluster tracks based on genome level similarity", at the Genomic HyperBrowser server: http://hyperbrowser.uio.no/hb/.     

Domestication causes rapid changes in heart and brain morphology in Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

Brain and heart development is very plastic in teleost fishes, and receptive to changes in social and environmental conditions. Domestication in salmonids has been reported to result in pronounced changes in both heart and brain morphology. In particular, a high prevalence of heart deformities has been reported in farmed salmonids, which has been linked to increased stress responsiveness that can impair survival of both farmed and escaped fish. Here we report for the first time that significant changes in heart and brain morphology occur following domestication of Atlantic cod (Gadus morhua), an emerging aquaculture species. Juvenile farmed cod developed significantly larger hearts and smaller brains, by weight, compared to their wild conspecifics. These differences occurred within the first captive generation, suggesting that they were driven largely by the strong contrast in environmental and social conditions experienced within their respective rearing environments. Changes in brain and heart morphology, as a consequence of domestication could affect the well-being and survival of Atlantic cod raised under intensive aquaculture conditions.