Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2017
Forfattere
Peeter Anijalg Simon Y. W. Ho John Davison Marju Keis Egle Tammeleht Katalina Bobowik Igor L. Tumanov Alexander P. Saveljev Elena A. Lyapunova Alexandr A. Vorobiev Nikolai I. Markov Alexey P. Kryukov Ilpo Kojola Jon Swenson Snorre Hagen Hans Geir Eiken Ladislav Paule Urmas SaarmaSammendrag
Aim Climatic changes during the Late Pleistocene had major impacts on populations of plant and animal species. Brown bears and other large mammals are likely to have experienced analogous ecological pressures and phylogeographical processes. Here, we address several unresolved issues regarding the Late Pleistocene demography of brown bears: (1) the putative locations of refugia; (2) the direction of migrations across Eurasia and into North America; and (3) parallels with the demographic histories of other wild mammals and modern humans. Location Eurasia and North America. Methods We sequenced 110 complete mitochondrial genomes from Eurasian brown bears and combined these with published sequences from 138 brown bears and 33 polar bears. We used a Bayesian approach to obtain a joint estimate of the phylogeny and evolutionary divergence times. The inferred mutation rate was compared with estimates obtained using two additional methods. Results Bayesian phylogenetic analysis identified seven clades of brown bears, with most individuals belonging to a very large Holarctic clade. Bears from the widespread clade 3a1, which has a distribution from Europe across Asia to Alaska, shared a common ancestor about 45,000 years ago. Main conclusions We suggest that the Altai-Sayan region and Beringia were important Late Pleistocene refuge areas for brown bears and propose large-scale migration scenarios for bears in Eurasia and to North America. We also argue that brown bears and modern humans experienced a demographic standstill in Beringia before colonizing North America.
Sammendrag
Jordbruksareal som går ut av drift gror etterhvert igjen med busker og kratt. Gjengroing medfører ikke bare tap av viktige arealressurser, men også kulturelle verdier og biologisk mangfold. Laserteknologi kan gjøre det mulig å registrere framvekst av busker og trær allerede i et tidlig stadium. Dette gir muligheter til å sette i gang tiltak for å motvirke denne utviklingen.
Forfattere
Eva Narten HøbergSammendrag
Det er ikke registrert sammendrag
Forfattere
Jihong Liu Clarke Lisa Paruch Mihaela-Olivia Dobrica Iuliana Caras Catalin Tucureanu Adrian Onu Sonya Ciulean Crina Stavaru Andre van Eerde Hege Særvold Steen Sissel Haugslien Catalina Petrareanu Catalin Lazar Ioan Popescu Ralph Bock Jean Dubuisson Norica Branza-NichitaSammendrag
Det er ikke registrert sammendrag
Forfattere
Jihong Liu Clarke Lisa Paruch Mihaela-Olivia Dobrica Iuliana Caras Catalin Tucureanu Adrian Onu Sonya Ciulean Crina Stavaru Andre van Eerde Yanliang Wang Hege Særvold Steen Sissel Haugslien Catalina Petrareanu Catalin Lazar Costin-loan Popescu Ralph Bock Jean Dubuisson Norica Branza-NichitaSammendrag
The hepatitis C virus (HCV) is a major etiologic agent for severe liver diseases ( e.g . cirrhosis, fibrosis and hepatocellular carcinoma). Approximately 140 million people have chronic HCV infections and about 500 000 die yearly from HCV-related liver pathologies. To date, there is no licensed vaccine available to prevent HCV infection and production of a HCV vaccine remains a major challenge. Here, we report the successful production of the HCV E1E2 heterodimer, an important vaccine candidate, in an edible crop (lettuce, Lactuca s ativa ) using Agrobacterium - mediated transient expression technology. The wild-type dimer (E1E2) and a variant without an N-glycosylation site in the E2 polypeptide (E1E2 Δ N6) were expressed, and appropriate N-glycosylation pattern and functionality of the E1E2 dimers were demonstrated. The humoral immune response induced by the HCV proteins was investigated in mice following oral administration of lettuce antigens with or without previous intramuscular prime with the mammalian HEK293T cell-expressed HCV dimer. Immunization by oral feeding only resulted in development of weak serum levels of anti-HCV IgM for both antigens; however, the E1E2 Δ N6 proteins produced higher amounts of secretory IgA, suggesting improved immunogenic properties of the N-glycosylation mutant. The mice group receiving the intramuscular injection followed by two oral boosts with the lettuce E1E2 dimer developed a systemic but also a mucosal immune response, as demonstrated by the presence of anti-HCV secretory IgA in faeces extracts. In summary, our study demonstrates the feasibility of producing complex viral antigens in lettuce, using plant transient expression technology, with great potential for future low-cost oral vaccine development.
Forfattere
Inger Martinussen Anne Linn Hykkerud Ivan Paponov Mette Thomsen Eivind Uleberg Laura JaakolaSammendrag
Det er ikke registrert sammendrag
Forfattere
Roselyn Labbe Irene Vänninen Nina Johansen A Nasreen Peter G. Kevan Cara McCreary Les ShippSammendrag
Det er ikke registrert sammendrag
Forfattere
Florencia A. Yannelli Christiane Koch Jonathan M. Jeschke Johannes KollmannSammendrag
Several hypotheses have been proposed to explain biotic resistance of a recipient plant community based on reduced niche opportunities for invasive alien plant species. The limiting similarity hypothesis predicts that invasive species are less likely to establish in communities of species holding similar functional traits. Likewise, Darwin’s naturalization hypothesis states that invasive species closely related to the native community would be less successful. We tested both using the invasive alien Ambrosia artemisiifolia L. and Solidago gigantea Aiton, and grassland species used for ecological restoration in central Europe. We classified all plant species into groups based on functional traits obtained from trait databases and calculated the phylogenetic distance among them. In a greenhouse experiment, we submitted the two invasive species at two propagule pressures to competition with communities of ten native species from the same functional group. In another experiment, they were submitted to pairwise competition with native species selected from each functional group. At the community level, highest suppression for both invasive species was observed at low propagule pressure and not explained by similarity in functional traits. Moreover, suppression decreased asymptotically with increasing phylogenetic distance to species of the native community. When submitted to pairwise competition, suppression for both invasive species was also better explained by phylogenetic distance. Overall, our results support Darwin’s naturalization hypothesis but not the limiting similarity hypothesis based on the selected traits. Biotic resistance of native communities against invasive species at an early stage of establishment is enhanced by competitive traits and phylogenetic relatedness.
Forfattere
Bjørn Egil FløSammendrag
Det er ikke registrert sammendrag
Forfattere
Bjørn Egil FløSammendrag
Det er ikke registrert sammendrag