| 1. |
- Clark, Andrew G., et al.
(författare)
-
Evolution of genes and genomes on the Drosophila phylogeny
- 2007
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
-
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.
|
|
| 2. |
|
|
| 3. |
- Clutton-Brock, T. H., et al.
(författare)
-
Intrasexual competition and sexual selection in cooperative mammals
- 2006
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 444:7122, s. 1065-1068
-
Tidskriftsartikel (refereegranskat)abstract
- In most animals, the sex that invests least in its offspring competes more intensely for access to the opposite sex and shows greater development of secondary sexual characters than the sex that invests most(1,2). However, in some mammals where females are the primary care-givers, females compete more frequently or intensely with each other than males(3-5). A possible explanation is that, in these species, the resources necessary for successful female reproduction are heavily concentrated and intrasexual competition for breeding opportunities is more intense among females than among males. Intrasexual competition between females is likely to be particularly intense in cooperative breeders where a single female monopolizes reproduction in each group(6). Here, we use data from a twelve-year study of wild meerkats (Suricata suricatta), where females show high levels of reproductive skew, to show that females gain greater benefits from acquiring dominant status than males and traits that increase competitive ability exert a stronger influence on their breeding success. Females that acquire dominant status also develop a suite of morphological, physiological and behavioural characteristics that help them to control other group members. Our results show that sex differences in parental investment are not the only mechanism capable of generating sex differences in reproductive competition and emphasize the extent to which competition for breeding opportunities between females can affect the evolution of sex differences and the operation of sexual selection.
|
|
| 4. |
- Dudeck, O., et al.
(författare)
-
Embolization of experimental wide-necked aneurysms with iodine-containing polyvinyl alcohol solubilized in a low-angiotoxicity solvent
- 2006
-
Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 27:9, s. 1849-1855
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: To evaluate the ready-to-use iodine-containing polyvinyl alcohol (I-PVA) dissolved in the low angiotoxic solvent N-methyl pyrrolidone (NMP) for embolization of porcine wide-necked aneurysms. METHODS: Fourteen broad-based carotid sidewall aneurysms were surgically constructed in 7 swine. I-PVA (40%) in NMP was injected under temporary balloon occlusion bridging the aneurysm neck. After 4 weeks, follow-up angiography, multisection CT angiography (MSCTA), and 3T MR imaging including MR angiography (MRA) sequences were performed. Afterward, harvested aneurysms were investigated histopathologically. RESULTS: The liquid embolic was well visible under fluoroscopy and displayed a favorable precipitation pattern, allowing for controlled polymer delivery. Ten aneurysms (71%) were initially completely occluded, whereas in 1 aneurysm, a minimal polymer leakage was observed. The other 4 aneurysms (29%) were almost completely occluded. One animal suffered a lethal rebleeding from the anastomosis after uneventful embolization. Aneurysms embolized with I-PVA could be discriminated well from the parent artery without beam-hardening artifacts on MSCTA, and no susceptibility artifacts were encountered on MR imaging. Histologic examination revealed all aneurysms covered with a membrane of fibroblasts and an endothelial cell layer while a moderate intraaneurysmal inflammatory response to the polymer was observed. CONCLUSION: I-PVA dissolved in NMP has proved its effectiveness for the embolization of experimental wide-necked aneurysms. This precipitating liquid embolic offers several interesting features in that it needs no preparation before use and no radiopaque admixtures, the latter allowing for artifact-free evaluation of treated aneurysms with MSCTA and MRA. Moreover, it uses NMP as a solvent, which has only a low angiotoxicity.
|
|
| 5. |
- Janke, J, et al.
(författare)
-
Angiotensin type 1 receptor antagonists induce human in-vitro adipogenesis through peroxisome prolifertor-activated receptor-gamma activation
- 2006
-
Ingår i: Journal of Hypertension. - : Ovid Technologies (Wolters Kluwer Health). - 0263-6352 .- 1473-5598. ; 24:9, s. 1809-1816
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In clonal animal cells, certain angiotensin receptor blockers (ARB) activate the peroxisome proliferator-activated receptor-gamma (PPARgamma). The aim of this work was to validate that observation in human cells and humans. METHODS: We investigated the induction of in-vitro adipogenesis and the activation of PPARgamma-target genes, adiponectin and lipoprotein lipase, by ARB in human preadipocytes. We also studied PPARgamma response-element-driven luciferase reporter gene activation in human adipocytes. Finally, we treated 14 obese men for 10 days with placebo crossed over with 150 mg/day irbesartan. Subcutaneous fat was analyzed for mRNA expression of adiponectin and lipoprotein lipase. RESULTS: Telmisartan and irbesartan, and to a lesser degree losartan, induced adipogenesis and activated PPARgamma-target genes. This stimulation of PPARgamma-target genes was prevented by the PPARgamma antagonist GW9662. Eprosartan had no effect. Paradoxically, all ARB activated the luciferase reporter gene. PPARgamma activity increased approximately two-fold with pioglitazone and 1.5-fold with the ARB in all assays. In the cross-over clinical study, irbesartan lowered blood pressure but had no effect on adiponectin or lipoprotein lipase mRNA expression. CONCLUSIONS: Our data are the first to show that ARB induce adipogenesis and PPARgamma-target gene expression in human adipocytes. Pharmacokinetic differences may contribute to the heterogeneous effects on metabolism and preadipocyte differentiation. In humans, larger doses of ARB, longer treatments, or both may be required to activate PPARgamma in adipose cells.
|
|
| 6. |
|
|
| 7. |
- Ryan, Mary H, et al.
(författare)
-
Proteolysis of purified IgGs by human and bacterial enzymes in vitro and the detection of specific proteolytic fragments of endogenous IgG in rheumatoid synovial fluid
- 2008
-
Ingår i: Molecular Immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 45:7, s. 1837-1846
-
Tidskriftsartikel (refereegranskat)abstract
- A comparative in vitro survey of physiologically relevant human and microbial proteinases defined a number of enzymes that induced specific hinge domain cleavage in human IgG1. Several of these proteinases have been associated with tumor growth, inflammation, and infection. A majority of the identified proteinases converted IgG to F(ab')(2), and a consistent feature of their action was a transient accumulation of a single-cleaved intermediate (scIgG). The scIgG resulted from the relatively rapid cleavage of the first hinge domain heavy chain, followed by a slower cleavage of the second chain to separate the Fc domain from F(ab')(2). Major sites of enzymatic cleavage were identified or confirmed from the mass of the F(ab')(2) or Fab fragments and/or the amino-terminal amino acid sequence of the Fc for each enzyme including human matrix metalloprotemases (MMPs) 3 and 12, human cathepsin G, human neutrophil elastase (Fab), staphylococcal glutamyl endopeptidase I and streptococcal immunoglobulin-degrading enzyme (Ides). The cleavage sites in IgG1 by MMP-3, cathepsin G and Ides were used to guide the synthesis of peptide analogs containing the corresponding carboxy-termini to be used as immunogens in rabbits. Rabbit antibodies were successfully generated that showed selective binding to different human F(ab')(2)s and other hinge-cleavage fragments, but not to intact IgG. In Western blotting studies of synovial fluids from individuals with rheumatoid arthritis, the rabbit antibodies yielded patterns consistent with the presence of endogenous IgG fragments including F(ab')(2) and the single-cleaved IgG intermediate. The detection in synovial fluid of IgG fragments similar to those observed in the in vitro biochemical studies suggests that proteolysis of IgG may contribute to localized immune dysfunction in inflammatory environments.
|
|
| 8. |
- Wang, Stephanie X., et al.
(författare)
-
The structure of chagasin in complex with a cysteine protease clarifies the binding mode and evolution of an inhibitor family
- 2007
-
Ingår i: Structure. - : Elsevier BV. - 0969-2126. ; 15:5, s. 535-543
-
Tidskriftsartikel (refereegranskat)abstract
- Protein inhibitors of proteolytic enzymes regulate proteolysis and prevent the pathological effects of excess endogenous or exogenous proteases. Cysteine proteases are a large family of enzymes found throughout the plant and animal kingdoms. Disturbance of the equilibrium between cysteine proteases and natural inhibitors is a key event in the pathogenesis of cancer, rheumatoid arthritis, osteoporosis, and emphysema. A family (142) of cysteine protease inhibitors (http://merops.sanger.ac.uk) was discovered in protozoan parasites and recently found widely distributed in prokaryotes and eukaryotes. We report the 2.2 A crystal structure of the signature member of the 142 family, chagasin, in complex with a cysteine protease. Chagasin has a unique variant of the immunoglobulin fold with homology to human CD8 alpha. Interactions of chagasin with a target protease are reminiscent of the cystatin family inhibitors. Protein inhibitors of cysteine proteases may have evolved more than once on nonhomologous scaffolds.
|
|
| 9. |
- Welch, J., et al.
(författare)
-
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
- 2009
-
Ingår i: Proceedings of the IEEE. - 1558-2256 .- 0018-9219. ; 97:8, s. 1438-1447
-
Tidskriftsartikel (refereegranskat)abstract
- The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to deliver data at the Hat Creek Radio Observatory in northern California. Scientists and engineers are actively exploiting all of the flexibility designed into this innovative instrument for simultaneously conducting surveys of the astrophysical sky and conducting searches for distant technological civilizations. This paper summarizes the design elements of the ATA, the cost savings made possible by the use of commercial off-the-shelf components, and the cost/performance tradeoffs that eventually enabled this first snapshot radio camera. The fundamental scientific program of this new telescope is varied and exciting; some of the first astronomical results will be discussed.
|
|
