| 1. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 2. |
- Willerslev, Eske, et al.
(författare)
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Ancient biomolecules from deep ice cores reveal a forested Southern Greenland
- 2007
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 317:5834, s. 111-114
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Tidskriftsartikel (refereegranskat)abstract
- It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.
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| 3. |
- Wood, Nigel I., et al.
(författare)
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Increased thirst and drinking in Huntington's disease and the R6/2 mouse
- 2008
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Ingår i: Brain Research Bulletin. - : Elsevier BV. - 0361-9230. ; 76:1-2, s. 70-79
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Tidskriftsartikel (refereegranskat)abstract
- While Huntington's disease (HD) is a condition that primarily involves the basal ganglia, there is evidence to suggest that the hypothalamus is also affected. Because the osmoreceptors regulating thirst are situated in the circumventricular region of the hypothalamus, we were interested in whether altered thirst is a part of the HD phenotype. We used the LABORAS behavioural monitoring system and water consumption to show that drinking behaviour was abnormal in R6/2 mice. By 10 weeks of age, R6/2 mice spent significantly more time drinking and drank a greater volume than their wild-type (WT) littermates. The numbers of immunoreactive vasopressin neurons in the paraventricular nucleus (PVN) of the hypothalamus in R6/2 mice were significantly decreased from 8 weeks of age, suggesting that the change in drinking behaviour may be the result of hypothalamic dysfunction. We gave a xerostomia (dry mouth) questionnaire to HD patients and control subjects, and also measured their urine osmolality and serum vasopressin. The mean total xerostomia score was significantly higher in HD patients than in controls, indicating greater thirst in HD patients. Urine osmolality was unaffected in HD patients up to clinical stage 111, and none of the patients had diabetes. However, serum vasopressin was increased, suggesting a dysregulation in the control of hypothalamic vasopressin release. A dry mouth can affect taste, mastication and swallowing, all of which may contribute to the significant weight loss seen in both HD patients and R6/2 mice, as can dehydration. We suggest that increased thirst may be an important and clinically relevant biomarker for the study of disease progression in HD.
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