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.
2009
Forfattere
Marit Larsen SekseSammendrag
The apple fruit moth (Argyresthia conjugella) is a serious pest in apples. It is a specialist seed predator of rowan, but the females will lay eggs on apples when rowan berries are scarce. Olfaction is important for many insect species in locating host plants. The odorant detection results from the association of odorous ligands with specific olfactory receptors, which are located in the membrane of the olfactory neurons. The aim of this work is to identify and characterize the odorant receptor genes and the genes involved in the regulation of the circadian olfactory response rhythm in the female apple fruit moth. In order to identify ORs, and other genes involved in olfaction, in the apple fruit moth a library of mRNA up-regulated in the antenna compared to the legs was made using subtractive hybridization. In total 864 clones have been sequenced. For 443 of the sequences no homology to known genes could be found using Blastx and blastn. Of the remaining sequences many have homology to genes that are known or believed to be involved in olfaction. These include odorant binding proteins, sensory neuron membrane proteins, chemosensory proteins, glutathione S-transferases, Odorant receptor 83b. This indicates that the subtraction has been successful and that the library is enriched in genes involved in olfaction. The sequences that it has not yet been possible to identify will be interesting for future studies.
Forfattere
Marit Larsen Sekse Sonja KlemsdalSammendrag
The apple fruit moth (Argyresthia conjugella) is a serious pest in apples. It is a specialist seed predator of rowan, but the females will lay eggs on apples when rowan berries are scarce. Olfaction is important for many insect species in locating host plants. The odorant detection results from the association of odorous ligands with specific olfactory receptors, which are located in the membrane of the olfactory neurons. The aim of this work is to identify and characterize the odorant receptor genes and the genes involved in the regulation of the circadian olfactory response rhythm in the female apple fruit moth. In order to identify ORs, and other genes involved in olfaction, in the apple fruit moth a library of mRNA up-regulated in the antenna compared to the legs was made using subtractive hybridization. In total 864 clones have been sequenced. For 443 of the sequences no homology to known genes could be found using Blastx and blastn. Of the remaining sequences many have homology to genes that are known or believed to be involved in olfaction. These include odorant binding proteins, sensory neuron membrane proteins, chemosensory proteins, glutathione S-transferases, Odorant receptor 83b. This indicates that the subtraction has been successful and that the library is enriched in genes involved in olfaction. The sequences that it has not yet been possible to identify will be interesting for future studies.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Genetic parameters were estimated for wood density and spiral grain in two long-term field trials with families of Picea abies (L.) Karst., and for microfibril angle (MfA) and model-predicted wood stiffness (MOEest) at one of the sites. The trials were located at 600-720 m altitude in Norway and the progenies, which were a sample of 13 half-sib families from plus-trees in a breeding population, were 33 years old from seed when measured. Significant genetic variation (p0.05) was found for all wood quality traits. The narrow-sense heritability was estimated to be 0.50 for density (across two sites), 0.38 for MfA, 0.29 for MOEest and 0.37 for spiral grain (across two sites). No significant genotype by environment interactions were found for density or spiral grain (p0.05). Genetic relationships between ring width and wood quality traits were negative for density and MOEest, and positive for MfA. Site index and competition had major effects on wood density and predicted MOEest but not on MfA and spiral grain.
Sammendrag
Klimaet er i endring. Prognosene tilsier at endringene skjer raskt og at de kan bli store. Klimaendringene vil kunne ha både positive og negative effekter på planteproduksjonen i Norge. Tilpasning av kulturplantene til det gjeldende klimaet er avgjørende for å kunne drive planteproduksjon, spesielt for flerårige vekster. Har vi sortsmateriale av viktige arter som er tilpasset det nye klimaet? Hvis ikke – har vi muligheter til å utvikle nye sorter raskt nok til å tilpasse oss klimaendringene?
Forfattere
Åke Olson Mikael Brandström Kajsa Himmelstrand Mårten Lind Magnus Karlsson K. Lunden Kerstin Dalman Heriberto Vélëz Björn Canbäck Francis Martin Halvor Solheim Carl Gunnar Fossdal Pierre Rouzé Yao-Cheng Lin Matteo Garbelotto Ursula Kües Igor V. Grigoriev Andrea Aerts Erika Lindquist Jeremy Schmutz Jan StenlidSammendrag
The genome sequence of the conifer rot root pathogen Heterobasidion annosum was generated at JGI with 8.23 X coverage. The nuclear genome assembles in 39 scaffolds of total 33.7 Mbp estimated to cover 98.1% of the complete genome. We predicted 12,270 genes with an average length of 1,617 bp and exon number and length of 5.54 and 250 bp respectively. About 50% (5999) of the predicted genes could be validated by EST support with the 40,807 EST´s generated with in the project. The genome has a GC content of 52.0% and very little repetitive sequences with 2,895 SSR per mega base. The physical genome is congruent with the genetic linkage map, and most of the linkage groups have been possible to anchor to the 18 largest scaffolds.
Forfattere
Geir Mathiesen Anita Sveen May Bente Brurberg Lasse Fredriksen Lars Axelsson Vincent EijsinkSammendrag
Background: Lactobacillus plantarum is a normal, potentially probiotic, inhabitant of the human gastrointestinal (GI) tract. The bacterium has great potential as food-grade cell factory and for in situ delivery of biomolecules. Since protein secretion is important both for probiotic activity and in biotechnological applications, we have carried out a genome-wide experimental study of signal peptide (SP) functionality.Results: We have constructed a library of 76 Sec-type signal peptides from L. plantarum WCFS1 that were predicted to be cleaved by signal peptidase I. SP functionality was studied using staphylococcal nuclease (NucA) as a reporter protein. 82% of the SPs gave significant extracellular NucA activity. Levels of secreted NucA varied by a dramatic 1800-fold and this variation was shown not to be the result of different mRNA levels. For the best-performing SPs all produced NucA was detected in the culture supernatant, but the secretion efficiency decreased for the less well performing SPs. Sequence analyses of the SPs and their cognate proteins revealed four properties that correlated positively with SP performance for NucA: high hydrophobicity, the presence of a transmembrane helix predicted by TMHMM, the absence of an anchoring motif in the cognate protein, and the length of the H+C domain. Analysis of a subset of SPs with a lactobacillal amylase (AmyA) showed large variation in production levels and secretion efficiencies. Importantly, there was no correlation between SP performance with NucA and the performance with AmyA.Conclusion: This is the first comprehensive experimental study showing that predicted SPs in the L. plantarum genome actually are capable of driving protein secretion. The results reveal considerable variation between the SPs that is at least in part dependent on the protein that is secreted. Several SPs stand out as promising candidates for efficient secretion of heterologous proteins in L. plantarum. The results for NucA provide some hints as to the sequence-based prediction of SP functionality, but the general conclusion is that such prediction is difficult. The vector library generated in this study is based on exchangeable cassettes and provides a powerful tool for rapid experimental screening of SPs.
Forfattere
Geir Mathiesen Anita Sveen May Bente Brurberg Lasse Fredriksen Lars Axelsson Vincent EijsinkSammendrag
Conclusion: This is the first comprehensive experimental study showing that predicted SPs in the L. plantarum genome actually are capable of driving protein secretion. The results reveal considerable variation between the SPs that is at least in part dependent on the protein that is secreted. Several SPs stand out as promising candidates for efficient secretion of heterologous proteins in L. plantarum. The results for NucA provide some hints as to the sequence-based prediction of SP functionality, but the general conclusion is that such prediction is difficult. The vector library generated in this study is based on exchangeable cassettes and provides a powerful tool for rapid experimental screening of SPs.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Karl Hilding Thunes Odd Ragnar Johnskås Åge Østgård Jan-Ole SkageSammendrag
Sibirsk edelgranlus (Adelges pectinatae) utgjør en av de alvorligste truslene mot juletre- og pyntegrøntproduksjon i Norge. Svært ofte blir prydtrær så sterkt angrepet at resultatet blir nåletap med betydelig utglisning av krona. Hvis unge trær blir angrepet eller hvis angrepet varer over lengre tid, kan trærne til slutt dø. Forsøk som Norsk institutt for skog og landskap har gjennomført i samarbeid med Skogfrøverket på Jønsberg landbruksskole viser at valg av proveniens er viktig for hvor mottakelig fjelledelgran (Abies lasiocarpa) er for sibirsk edelgranlus.