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- Tuskan, G A, et al.
(författare)
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The genome of black cottonwood, Populus trichocarpa (Torr. & Gray).
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 313:5793, s. 1596-604
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Tidskriftsartikel (refereegranskat)abstract
- We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.
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| 2. |
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| 3. |
- Petersson, Sara, et al.
(författare)
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An auxin gradient and maximum in the arabidopsis root apex shown by high-resolution cell-specific analysis of IAA distribution and synthesis
- 2009
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 21:6, s. 1659-1668
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Tidskriftsartikel (refereegranskat)abstract
- Local concentration gradients of the plant growth regulator auxin (indole-3-acetic acid [IAA]) are thought to instruct the positioning of organ primordia and stem cell niches and to direct cell division, expansion, and differentiation. High-resolution measurements of endogenous IAA concentrations in support of the gradient hypothesis are required to substantiate this hypothesis. Here, we introduce fluorescence-activated cell sorting of green fluorescent protein-marked cell types combined with highly sensitive mass spectrometry methods as a novel means for analyses of IAA distribution and metabolism at cellular resolution. Our results reveal the presence of IAA concentration gradients within the Arabidopsis thaliana root tip with a distinct maximum in the organizing quiescent center of the root apex. We also demonstrate that the root apex provides an important source of IAA and that cells of all types display a high synthesis capacity, suggesting a substantial contribution of local biosynthesis to auxin homeostasis in the root tip. Our results indicate that local biosynthesis and polar transport combine to produce auxin gradients and maxima in the root tip.
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| 4. |
- Sandberg, Karl W, et al.
(författare)
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The Role of Human Factors in Design and Implementation of Electronic Public Information Systems
- 2007
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Ingår i: Engineering Psychology and Cognitive Ergonomics, Proceedings. - Berlin : Springer. - 9783540733300 ; , s. 164-173
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Konferensbidrag (refereegranskat)abstract
- Design of Electronic Public Information Systems (e-PIS) can benefit from the inclusion of guidelines that consider the needs of users. Inclusion of guidelines and prototyping practices that take into consideration the capabilities of human users make it possible to avoid errors that would otherwise significantly reduce efficiencies offered by Informationtechnology (IT). Design strategies that include consideration of the Human Factor (HF) within e-PIS are introduced and discussed. Argued is that without integration of design strategies that consider human capabilities the efficiencies brought about through the use of electronic technology are significantly reduced. Through the study of intended user behaviours during the development of systems loss of efficiency is avoided.
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