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71.
Erling Johan Solberg Thor Harald Ringsby Andreas Altwegg Bernt-Erik Sæther 《Journal of Ornithology》2000,141(1):102-104
Summary Viability and a seemingly successful breeding of a F1 House Sparrow x Tree Sparrow hybrid are reported from islands off the coast of northern Norway. From two consecutive clutches of House Sparrow x Tree Sparrow hybrids recorded in 1995, only one of 7 chicks survived the first year. The surviving individual was later, in 1997, found attending the nest with a female House Sparrow and feeding the young in two consecutive clutches. Neither of the F2 hybrids were observed after fledging. Despite the fact that House Sparrows indulge in frequent extra pair copulation, we find it unlikely that both clutches fed by the male hybrid could have been fathered by a House Sparrow male and therefore conclude that the F1 male hybrid was fertile. The hybridisation may have been facilitated by the fragmented structure and small size (from 5 to 100 individuals) of the sub-populations found in our study area.
Fertile Haus- x Feldsperling (Passer domesticus X Passer montanus) Hybride?
Zusammenfassung Wir berichten über die Überlebensfähigkeit und einen offenbar erfolgreichen Brutversuch eines F1 Haussperling x Feldsperling Hybriden auf Inseln vor der nordnorwegischen Küste. Aus zwei aufeinanderfolgenden Gelegen eines gemischten Haus-/Feldsperling Paares, die wir 1995 beobachtet hatten, überlebte nur eines von sieben Jungtieren das erste Jahr. Das überlebende Individuum nistete später, 1997, mit einem Haussperlingweibchen und fütterte die Jungen zweier aufeinanderfolgender Bruten. Keiner der F2 Hybriden wurde nach dem Schlüpfen beobachtet. Obwohl bei Haussperlingen Kopulationen außerhalb des Paares häufig sind, betrachten wir es als unwahrscheinlich, daß beide vom männlichen Hybriden gefütterten Bruten von einem Haussperlingmännchen gezeugt worden waren. Wir schließen deshalb, daß das F1 Hybridmännchen fruchtbar war. Die Hybridisierung könnte durch die fragmentierte Struktur und die kleine Größe (5 bis 100 Individuen) der lokalen Populationen erleichtert worden sein.相似文献
72.
Robert Smith Rigmor Solberg Linn L?kken Jacobsen Anette Larsen Voreland Arild Christian Rustan G. Hege Thoresen Harald Thidemann Johansen 《PloS one》2014,9(1)
Simvastatin, a HMG-CoA reductase inhibitor, is prescribed worldwide to patients with hypercholesterolemia. Although simvastatin is well tolerated, side effects like myotoxicity are reported. The mechanism for statin-induced myotoxicity is still poorly understood. Reports have suggested impaired mitochondrial dysfunction as a contributor to the observed myotoxicity. In this regard, we wanted to study the effects of simvastatin on glucose metabolism and the activity of legumain, a cysteine protease. Legumain, being the only known asparaginyl endopeptidase, has caspase-like properties and is described to be involved in apoptosis. Recent evidences indicate a regulatory role of both glucose and statins on cysteine proteases in monocytes. Satellite cells were isolated from the Musculus obliquus internus abdominis of healthy human donors, proliferated and differentiated into polynuclear myotubes. Simvastatin with or without mevalonolactone, farnesyl pyrophosphate or geranylgeranyl pyrophosphate were introduced on day 5 of differentiation. After 48 h, cells were either harvested for immunoblotting, ELISA, cell viability assay, confocal imaging or enzyme activity analysis, or placed in a fuel handling system with [14C]glucose or [3H]deoxyglucose for uptake and oxidation studies. A dose-dependent decrease in both glucose uptake and oxidation were observed in mature myotubes after exposure to simvastatin in concentrations not influencing cell viability. In addition, simvastatin caused a decrease in maturation and activity of legumain. Dysregulation of glucose metabolism and decreased legumain activity by simvastatin points out new knowledge about the effects of statins on skeletal muscle, and may contribute to the understanding of the myotoxicity observed by statins. 相似文献
73.
74.
Ivar Herfindal Hallvard Haanes Knut H. R?ed Erling J. Solberg Stine S. Markussen Morten Heim Bernt-Erik S?ther 《Biology letters》2014,10(12)
Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations. 相似文献
75.
Genetic discontinuities in a continuously distributed and highly mobile ungulate,the Norwegian moose
H. Haanes K. H. Røed E. J. Solberg I. Herfindal B.-E. Sæther 《Conservation Genetics》2011,12(5):1131-1143
Many species with currently continuously distributed populations have histories of geographic range shifts and successive
shifts between decline or fragmentation, growth and spatial expansion. The moose (Alces alces) colonised Scandinavia after the last ice age. Historic records document a high abundance and a wide distribution across
Norway in the middle ages, but major decline and fragmentation in the eighteenth and nineteenth centuries. After growth and
expansion during the twentieth century, the Norwegian population is currently abundant and continuously distributed. We examined
the distribution of genetic variation, differentiation and admixture in Norwegian moose, using 15 microsatellites. We assessed
whether admixture has homogenised the population or if there are any genetic structures or discontinuities that can be related
to recent or ancient shifts in demography or distribution. The Bayesian clustering algorithm STRUCTURE without any spatial
information showed that there is currently a genetic dichotomy dividing the population into one southern and one northern
subpopulation. Including spatial information, the Bayesian clustering algorithm TESS, which considers gradients of genetic
variation and spatial autocorrelation, suggests that the population is divided into three subpopulations along a latitudinal
axis, the southern one identical to the one identified with STRUCTURE. Present convergence zones of high admixture separate
the identified subpopulations, which are delimited by genetic discontinuities corresponding to geographic barriers against
dispersal, e.g. wide fiords and mountain ranges. The distribution of the subpopulations is supported by spatial autocorrelation
analysis. However, some loci are not in Hardy–Weinberg equilibrium and the STRUCTURE analysis suggests that a lower hierarchical
structure may exist within the southernmost subpopulation. No bottlenecks or founder events are indicated by the levels of
genetic variation, rather a high degree of private alleles in the northern subpopulations indicates introgression. Coalescent-based
Approximate Bayesian Computation estimates unambiguously suggest that the genetic structure is a result of an ancient divergence
event and a more recent admixture event a few centuries ago. This indicates that the central Scandinavian subpopulation constitutes
a relatively recent convergence zone of secondary contact. 相似文献
76.
Hanyoup Kim Mais J. Jebrail Anupama Sinha Zachary W. Bent Owen D. Solberg Kelly P. Williams Stanley A. Langevin Ronald F. Renzi James L. Van De Vreugde Robert J. Meagher Joseph S. Schoeniger Todd W. Lane Steven S. Branda Michael S. Bartsch Kamlesh D. Patel 《PloS one》2013,8(7)
Next-generation sequencing (NGS) is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF) sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM). The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories. 相似文献
77.
R?nnaug Solberg Javier Escobar Alessandro Arduini Isabel Torres-Cuevas Agustín Lahoz Juan Sastre Ola Didrik Saugstad Máximo Vento Julia Kuligowski Guillermo Quintás 《PloS one》2013,8(6)
The availability of reliable biomarkers of brain injury secondary to birth asphyxia could substantially improve clinical grading, therapeutic intervention strategies, and prognosis. In this study, changes in the metabolome of retinal tissue caused by profound hypoxia in an established neonatal piglet model were investigated using an ultra performance liquid chromatography – quadrupole time of flight mass spectrometry (UPLC-QTOFMS) untargeted metabolomic approach, which included Partial Least Squares – Discriminant Analysis (PLSDA) multivariate data analysis. The initial identification of a set of discriminant metabolites from UPLC-QTOFMS data was confirmed by target UPLC-MS/MS and allowed the selection of endogenous CDP-choline as a promising candidate biomarker for hypoxia-derived brain damage assessing intensity of retinal hypoxia. Results from this study will foster further research on CDP-choline changes occurring during resuscitation. 相似文献
78.
Ping Wang Quanli Gao Zhenhe Suo Else Munthe Steinar Solberg Liwei Ma Mengyu Wang Nomdo Anton Christiaan Westerdaal Gunnar Kvalheim Gustav Gaudernack 《PloS one》2013,8(3)
Lung cancer (LC) with its different subtypes is generally known as a therapy resistant cancer with the highest morbidity rate worldwide. Therapy resistance of a tumor is thought to be related to cancer stem cells (CSCs) within the tumors. There have been indications that the lung cancer is propagated and maintained by a small population of CSCs. To study this question we established a panel of 15 primary lung cancer cell lines (PLCCLs) from 20 fresh primary tumors using a robust serum-free culture system. We subsequently focused on identification of lung CSCs by studying these cell lines derived from 4 representative lung cancer subtypes such as small cell lung cancer (SCLC), large cell carcinoma (LCC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). We identified a small population of cells strongly positive for CD44 (CD44high) and a main population which was either weakly positive or negative for CD44 (CD44low/−). Co-expression of CD90 further narrowed down the putative stem cell population in PLCCLs from SCLC and LCC as spheroid-forming cells were mainly found within the CD44highCD90+ sub-population. Moreover, these CD44highCD90+ cells revealed mesenchymal morphology, increased expression of mesenchymal markers N-Cadherin and Vimentin, increased mRNA levels of the embryonic stem cell related genes Nanog and Oct4 and increased resistance to irradiation compared to other sub-populations studied, suggesting the CD44highCD90+ population a good candidate for the lung CSCs. Both CD44highCD90+ and CD44highCD90− cells in the PLCCL derived from SCC formed spheroids, whereas the CD44low/− cells were lacking this potential. These results indicate that CD44highCD90+ sub-population may represent CSCs in SCLC and LCC, whereas in SCC lung cancer subtype, CSC potentials were found within the CD44high sub-population. 相似文献
79.
80.
Victoria T. González Olavi Junttila Bente Lindgård Rigmor Reiersen Kajetan Trost Kari Anne Bråthen 《Nordic Journal of Botany》2015,33(2):225-231
Batatasin‐III (3,3‐dihydroxy‐5‐methoxybibenzyl) is a phenolic compound associated with the allelopathic effect of the evergreen dwarf shrub Empetrum nigrum, and has been referred to as the causal factor for the species being successful in dominating extensive ecosystems. Yet, only a few plant species have been tested for their response to batatasin‐III, and little is known about whether environmental factors modify this allelopathic effect. In this study, we tested the inhibitory effect of purified batatasin‐III through bioassays on 24 vascular plant species and, for certain species, we tested if this effect depended on growth substrate (mineral vs organic substrate), pH, and fertilization. Moreover, we tested if batatasin‐III predicted the allelopathic effect of E. nigrum by analyzing the inhibitory effect of E. nigrum leaves and humus in relation to their batatasin‐III content. Our results confirmed batatasin‐III as a stable compound capable of inhibiting germination and/or mean root elongation in all of the tested species, but this effect was modified by growth substrate. Surprisingly, the measured batatasin‐III content of E. nigrum leaves (mean value 19.7 ± 10.8 (SE) mg g?1) and humus (mean value of 1 ± 1.5 (SE) μg g?1) did not predict the inhibitory effect on mean root elongation. Although batatasin‐III was found to be phytotoxic to all the tested species, we conclude that this substance alone should not be used as a proxy for the allelopathic effect of E. nigrum. 相似文献