Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2014
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Anette Aamodt Moldestad Bernt Hoel Ulrike Böcker Shiori Koga Ellen Færgestad Mosleth Anne Kjersti UhlenAbstract
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Igor A. Yakovlev YeonKyeong Lee Björn Rotter Jorunn Elisabeth Olsen Tore Skrøppa Øystein Johnsen Carl Gunnar FossdalAbstract
Embryogenesis is the initial stage of plant life, when the basics of body plan and the post-embryonic development are laid down. Epigenetic memory formed in the Norway spruce embryos permanently affect the timing of bud burst and bud set in progenies, vitally important adaptive traits in this long-lived forest species. The epigenetic memory marks are established in response to the temperature conditions prevailing during zygotic and somatic embryogenesis; the epitype is fixed by the time the embryo is fully developed and is mitotically propagated throughout the tree’s life span. Somatic embryogenesis closely mimics the natural zygotic embryo formation and results in epigenetically different plants in a predictable temperature-dependent manner with respect to altered phenology. Using Illumina-based Massive Analysis of cDNA Ends, the transcriptome changes were monitored in somatic embryos during morphogenesis stage under two different temperatures (18 vs. 30 °C). We found distinct differences in transcriptomes between the genetically identical embryogenic tissues grown under the two epitype-inducing temperatures suggesting temperature-dependent canalizing of gene expression during embryo formation, putatively based on chromatin modifications. From 448 transcripts of genes coding for proteins involved in epigenetic machinery, we found 35 of these to be differentially expressed at high level under the epitype-inducing conditions. Therefore, temperature conditions during embryogenesis significantly alter transcriptional profiles including numerous orthologs of transcriptional regulators, epigenetic-related genes, and large sets of unknown and uncharacterized transcripts.
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Theo RuissenAbstract
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Per Stålnacke Marianne Bechmann Arvo Iital Hans Estrup Andersen Katarina Kyllmar Jari Koskiaho Ainis Lagzdins Viesturs Jansons Antanas Sigitas Sileika Kazimieras GaigalisAbstract
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Per Stålnacke Paul Aakerøy Gitte Blicher-Mathiesen Arvo Iital Viesturs Jansons Jari Koskiaho Katarina Kyllmar Ainis Lagzdins Annelene Pengerud Arvydas PovilaitisAbstract
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Authors
Alexander Kopatz Paul Eric Aspholm Anja Rudolph Hans Geir Eiken Julia Schregel Siv Aarnes Camilla Tobiassen Snorre HagenAbstract
Genetic methods based on sampling of feces and hairs to study brown bears have become the method of choice for many wildlife researchers and managers. Feces and hairs are the most common sample material for DNA identification of individual bears. While the collection of feces and hairs in the field is carried out in an opportunistic manner, hair-trapping can be applied systematically at specific locations. We have here tested a novel systematic method based on hair sampling on power poles. The method relies on the specific behavior of bears to mark, scratch, bite and scrub on power poles, and by this also leave some hairs behind. During late summer and autumn we have investigated 215 power poles in the Pasvik Valley and sampled 181 hair samples in 2013 and 57 in 2014. A total of 17.3% of the samples collected in 2013 and 12.3% in 2014 were positive on brown bear DNA. Our success rates are comparable to other studies, however, DNA quality/content in the hair samples was generally low. Based on other studies, the method could be improved by sampling during spring and early summer and to use shorter frequencies of 2 to 4 weeks between each sampling. Based on our results and previous studies, we can conclude that this sampling technique should be improved by the development of a more accurate and frequent sampling protocol. Hair sampling from power poles may then lead to improved potential to collect valuable samples and information, which would be more difficult to collect otherwise.