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- Gunnarsson, Ulrika
(author)
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Genetic Studies of Pigmentation in Chicken
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Domestic animals have been selected by humans for thousands of years, which have drastically altered their genetic constitution and phenotypes. In this thesis, several of the most important genes causing pigmentation differences between the wild red junglefowl (Gallus gallus) and domestic chickens have been identified. Pigmentation phenotypes are easily scored, and the genes underlying these phenotypes are valuable models to study gene function and gene interaction. Dominant white colour is widespread among domestic chickens. The Dominant white allele specifically inhibits the expression of black (eumelanin) pigment and we identified several insertion/deletion mutations in the PMEL17 gene causing the different phenotypes controlled by this locus. The Silver allele on the other hand inhibits the expression of red (pheomelanin) colour and is a genetic variant of the SLC45A2 gene. Silver is the first pheomelanin-specific mutation(s) reported for this gene. An 8 kb deletion, including a conserved enhancer element, 14 kb upstream of the transcription factor SOX10 is causing the Dark brown phenotype. This phenotype restricts the expression of eumelanin and enhances red pheomelanin in specific parts of the plumage. These three gene identifications have extended the knowledge about genes affecting melanocyte function. Carotenoid-based pigmentation is of utmost importance in birds and other animals. The yellow skin allele in chicken allows deposition of carotenoids in skin and explains why most domestic chickens have yellow legs. We demonstrated that the yellow skin phenotype is caused by a tissue specific regulatory mutation in the gene for the enzyme beta-caroten dioxygenase 2 (BCDO2). This was the first identification of a specific gene underlying carotenoid-based pigmentation. Interestingly, the yellow skin haplotype was shown to originate from the grey junglefowl (Gallus sonneratii) and not the red junglefowl as expected, thus presenting the first conclusive evidence for a hybrid origin of the domestic chicken.
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- Aidemark, Mari, et al.
(author)
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Regulation of callose synthase activity in situ in alamethicin-permeabilized Arabidopsis and tobacco suspension cells
- 2009
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In: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 9
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Journal article (peer-reviewed)abstract
- Background: The cell wall component callose is mainly synthesized at certain developmental stages and after wounding or pathogen attack. Callose synthases are membrane-bound enzymes that have been relatively well characterized in vitro using isolated membrane fractions or purified enzyme. However, little is known about their functional properties in situ, under conditions when the cell wall is intact. To allow in situ investigations of the regulation of callose synthesis, cell suspensions of Arabidopsis thaliana (Col-0), and tobacco (BY-2), were permeabilized with the channel-forming peptide alamethicin. Results: Nucleic acid-binding dyes and marker enzymes demonstrated alamethicin permeabilization of plasma membrane, mitochondria and plastids, also allowing callose synthase measurements. In the presence of alamethicin, Ca2+ addition was required for callose synthase activity, and the activity was further stimulated by Mg2+ Cells pretreated with oryzalin to destabilize the microtubules prior to alamethicin permeabilization showed significantly lower callose synthase activity as compared to non-treated cells. As judged by aniline blue staining, the callose formed was deposited both at the cell walls joining adjacent cells and at discrete punctate locations earlier described as half plasmodesmata on the outer walls. This pattern was unaffected by oryzalin pretreatment, showing a quantitative rather than a qualitative effect of polymerized tubulin on callose synthase activity. No callose was deposited unless alamethicin, Ca2+ and UDP-glucose were present. Tubulin and callose synthase were furthermore part of the same plasma membrane protein complex, as judged by two-dimensional blue native SDS-PAGE. Conclusion: Alamethicin permeabilization allowed determination of callose synthase regulation and tubulin interaction in the natural crowded cellular environment and under conditions where contacts between the cell wall, the plasma membrane and cytoskeletal macromolecules remained. The results also suggest that alamethicin permeabilization induces a defense response mimicking the natural physical separation of cells (for example when intercellulars are formed), during which plasmodesmata are transiently left open.
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- Andersson, Agneta, et al.
(author)
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Towards a healhty diet: from nutrition recommendations to dietary advice
- 2007
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In: Scandinavian Journal of Food & Nutrition. - : Informa UK Limited. - 1748-2976 .- 1748-2984. ; 51:1, s. 31-40
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Journal article (peer-reviewed)abstract
- The scientific knowledge regarding dietary fat, carbohydrate and protein, and food for the youngest and oldest people, was presented by key scientists in the field at a symposium arranged in Uppsala on 14 December 2006. The quality of fat and carbohydrates, rather than the total amount, was emphasized. It was more difficult, however, to reach conclusions about the preferred type of dietary protein. Recent dietary recommendations, main activities and key messages to the public in the Nordic countries, and a 5 year programme to decrease salt intake in Sweden were also presented. Some practical aspects on how to implement the recommendations in the population were highlighted. In many aspects the Nordic countries join together in similar simplified advice to the population. The symposium is summarized in this report.
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- Andersson, Fredrik, 1977, et al.
(author)
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Structure and function of a novel type of ATP-dependent Clp protease.
- 2009
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In: The Journal of biological chemistry. - 0021-9258 .- 1083-351X. ; 284:20, s. 13519-32
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Journal article (peer-reviewed)abstract
- The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. The main constitutive Clp protease in photosynthetic organisms has evolved into a functionally essential and structurally intricate enzyme. The model Clp protease from the cyanobacterium Synechococcus consists of the HSP100 molecular chaperone ClpC and a mixed proteolytic core comprised of two distinct subunits, ClpP3 and ClpR. We have purified the ClpP3/R complex, the first for a Clp proteolytic core comprised of heterologous subunits. The ClpP3/R complex has unique functional and structural features, consisting of twin heptameric rings each with an identical ClpP3(3)ClpR(4) configuration. As predicted by its lack of an obvious catalytic triad, the ClpR subunit is shown to be proteolytically inactive. Interestingly, extensive modification to ClpR to restore proteolytic activity to this subunit showed that its presence in the core complex is not rate-limiting for the overall proteolytic activity of the ClpCP3/R protease. Altogether, the ClpP3/R complex shows remarkable similarities to the 20 S core of the proteasome, revealing a far greater degree of convergent evolution than previously thought between the development of the Clp protease in photosynthetic organisms and that of the eukaryotic 26 S proteasome.
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- Andersson, Gunnar, et al.
(author)
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Analys av polisens alkoholutandningsprov i fem län åren 2001-2003
- 2007
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Reports (other academic/artistic)abstract
- The extent and results of the police breathalyser tests in Stockholm, Västerbotten, Östergötland, Skåne and Västra Götaland Counties over the period 2001-2003 have been analysed. The primary aim is to uncover and describe shortcomings in existing data, not to estimate the extent of drink driving. The analysis has been made with reference to the codes applied by the police to describe the type of control at which the test was made. These codes are - 0) Police initiated driver control - 1) "Random" control (not random in the strict statistical sense) - 2) Control because of a road traffic accident - 3) Targeted control (e.g. at strategically selected points such as shops selling alcoholic drinks) - 4) Other codes - It is mainly the breathalyser tests coded by the police as 0, 1 and 3 that are examined in the analysis. The other codes appear very rarely in the controls made.
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- Andersson, Karin, et al.
(author)
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A two-year clinical lifestyle intervention program for weight loss in obesity
- 2008
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In: Food & nutrition research. - : Co-Action Publishing. - 1654-661X .- 1654-6628. ; 52, s. 1656-
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Journal article (peer-reviewed)abstract
- BACKGROUND: In recent randomised prospective studies, lifestyle intervention induced a weight loss of approximately 5%. OBJECTIVE: To describe and evaluate a 2-year on-going group intervention program in clinical practice in terms of weight loss and changes in metabolic risk factors, i.e. sagital abdominal diameter (SAD), triglycerides, fasting blood glucose and blood pressure. DESIGN: The aim of the intervention program was to motivate lifestyle changes concerning food intake and physical activity. The emphasis was on lifestyle modification, followed up at regular visits during 2 years. Subjects evaluated were 100 women with mean BMI 37.6 kg/m(2) and 26 men with mean BMI 36.5 kg/m(2). RESULTS: One hundred of 151 enrolled women and 26 of 36 men completed the program. Mean weight decreased by 3.8 kg in women (from 103.5 to 99.7, p<0.001) and 4.4 kg in men (from 116.5 to 112.1, p<0.05), respectively. SAD decreased by 5% (p=0.001 in women, p=0.01 in men), and triglycerides by 16% in women (p=0.01) and 24% in men (p=0.001), however systolic and diastolic blood pressure increased slightly but significantly. CONCLUSION: It is possible to perform a clinical lifestyle intervention program for outpatients on an ongoing basis with weight loss, lowered SAD and triglycerides, and a similar or lower dropout rate compared to clinical trials.
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