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91.
Marie Admkov Zuzana Bílkov Oldich Tomek Zdenk imek Tom Albrecht 《Ecology and evolution》2019,9(16):9018-9026
In birds, concentrations of testosterone (T) and corticosterone (Cort) are closely connected with many morphological, behavioral, and other physiological traits, including reproduction, metabolism, immunity, and fitness. The direction of the effect of these hormones on above‐mentioned traits, and the potential feedback between hormones are in general unclear; in addition, knowledge on how age and sex can affect T and Cort concentrations is still inconsistent. Our study used a novel method to analyze testosterone and corticosterone in feathers (Tf, Cortf) based on the precolumn chemical derivatization of hormones before liquid chromatography–tandem mass spectrometry (LC‐MS/MS) analysis. Unlike previously used methods (RIA, EIA), our analytical procedure allows simultaneous analysis of both hormones from small amounts of feathers (4–25 mg) and, thus, overcomes the problem of insufficient detection limits. We applied this method to reveal associations between Tf and Cortf hormone concentrations and feather growth, age, and sex in feathers grown during the postbreeding (flanks) and prebreeding (tails) periods in barn swallows (Hirundo rustica). There was neither a correlation between prebreeding and postbreeding Tf, nor between prebreeding and postbreeding Cortf. Tail Cortf concentrations were negatively associated with tail feather growth rates. Feather hormone concentrations were correlated in the prebreeding period, negatively in males but positively in females. Both Cortf and Tf were higher in young birds compared to older ones, indicating either an age‐related decrease in hormone concentrations within individuals, or the selective disappearance of individuals with high steroid concentrations. Males and females did not differ in Cortf, but Tf concentrations were higher in males than females, particularly during the prebreeding period. In this study, we provide an effective method for analyzing hormones in feathers in an ecological context, especially in situations when the total amount of feathers available for the analysis is limited. 相似文献
92.
Wang GL Shi X Salisbury E Sun Y Albrecht JH Smith RG Timchenko NA 《The Journal of biological chemistry》2007,282(2):1468-1478
93.
Moeller R Horejsi R Pilz S Lang N Sargsyan K Dimitrova R Tafeit E Giuliani A Almer G Mangge H 《Obesity (Silver Spring, Md.)》2007,15(5):1319-1324
Objective: To compare subcutaneous adipose tissue topography (SAT‐top) in obese juveniles with age‐matched normal‐weight controls. Research Methods and Procedures: The optical device LIPOMETER (European Patent EP 0516251) enables the non‐invasive, rapid, safe, and precise measurement of the thickness of subcutaneous adipose tissue. Fifteen defined body sites (1 = neck to 15 = calf) characterize the individual SAT‐top like an individual fingerprint. SAT‐top of 1351 juveniles (obese: 42 boys, 59 girls, normal weight: 680 boys, 570 girls) from 7 to 19 years of age were measured. For visual comparison, the 15‐dimensional SAT‐top information was condensed by factor analysis into a two‐dimensional factor plot. Results: Both female and male obese juveniles had markedly increased adipose tissue layers at 7 = upper abdomen, 8 = lower abdomen, 5 = front chest, and 6 = lateral chest. The pubertal changes of body shape and fat distribution of the normal‐weight boys and girls (boys show thinner adipose tissue layers on their legs, whereas girls had thicker adipose tissue layers at the extremities) were not seen in the obese group. Independently of age and sex, all of the obese juveniles showed a similar, more android body fat distribution with increased trunk fat. Discussion: SAT‐top of the obese juveniles is similar to that of patients with type 2 diabetes, polycystic ovary syndrome, and coronary heart disease. Patients with these metabolic disorders and obese juveniles are located in the factor plot in the same area. This body shape may indicate a risk profile for developing polycystic ovary syndrome (women), type 2 diabetes, and early atherosclerosis (both sexes). 相似文献
94.
von Brunn A Teepe C Simpson JC Pepperkok R Friedel CC Zimmer R Roberts R Baric R Haas J 《PloS one》2007,2(5):e459
The severe acute respiratory syndrome coronavirus (SARS-CoV) genome is predicted to encode 14 functional open reading frames, leading to the expression of up to 30 structural and non-structural protein products. The functions of a large number of viral ORFs are poorly understood or unknown. In order to gain more insight into functions and modes of action and interaction of the different proteins, we cloned the viral ORFeome and performed a genome-wide analysis for intraviral protein interactions and for intracellular localization. 900 pairwise interactions were tested by yeast-two-hybrid matrix analysis, and more than 65 positive non-redundant interactions, including six self interactions, were identified. About 38% of interactions were subsequently confirmed by CoIP in mammalian cells. Nsp2, nsp8 and ORF9b showed a wide range of interactions with other viral proteins. Nsp8 interacts with replicase proteins nsp2, nsp5, nsp6, nsp7, nsp8, nsp9, nsp12, nsp13 and nsp14, indicating a crucial role as a major player within the replication complex machinery. It was shown by others that nsp8 is essential for viral replication in vitro, whereas nsp2 is not. We show that also accessory protein ORF9b does not play a pivotal role for viral replication, as it can be deleted from the virus displaying normal plaque sizes and growth characteristics in Vero cells. However, it can be expected to be important for the virus-host interplay and for pathogenicity, due to its large number of interactions, by enhancing the global stability of the SARS proteome network, or play some unrealized role in regulating protein-protein interactions. The interactions identified provide valuable material for future studies. 相似文献
95.
Strathmann J Paal K Ittrich C Krause E Appel KE Glauert HP Buchmann A Schwarz M 《Proteomics》2007,7(18):3318-3331
Mouse liver tumors frequently harbor mutations in Ha-ras, B-raf, or Ctnnb1 (encoding beta-catenin). We conducted a proteome analysis with protein extracts from normal mouse liver and from liver tumors which were induced by a single injection of N-nitrosodiethylamine (DEN) as initiator followed by multiple injections of two different polychlorinated biphenyls (PCBs) as tumor promoters, or corn oil as a control. Liver tumors were stratified into two classes: they were either mutated in Ctnnb1 and positive for the marker glutamine synthetase (GS(+)), or they lacked Ctnnb1 mutations and were therefore GS-negative (GS(-)). Proteome analysis by 2-DE and MS revealed 98 significantly deregulated proteins, 44 in GS(+) and 54 in GS(-) tumors. Twelve of these proteins showed expression changes in both tumor types, but only seven of them were deregulated in the same direction. Several of the identified enzymes could be assigned to fundamental metabolic or other cellular pathways with characteristically different alterations in GS(+) and GS(-) tumors such as ammonia and amino acid turnover, cellular energy supply, and calcium homeostasis. Our data suggest that GS(+) and GS(-) tumor cells show a completely different biology and use divergent evolutionary strategies to gain a selective advantage over normal hepatocytes. 相似文献
96.
97.
Various proteins have been found to play roles in both the repair of UV damaged DNA and heterochromatin-mediated silencing in the yeast Saccharomyces cerevisiae. In particular, factors that are involved in the methylation of lysine-79 of histone H3 by Dot1p have been implicated in both processes, suggesting a bipartite function for this modification. We find that a dot1 null mutation and a histone H3 point mutation at lysine-79 cause increased sensitivity to UV radiation, suggesting that lysine-79 methylation is important for efficient repair of UV damage. Epistasis analysis between dot1 and various UV repair genes indicates that lysine-79 methylation plays overlapping roles within the nucleotide excision, post-replication and recombination repair pathways, as well as RAD9-mediated checkpoint function. In contrast, epistasis analysis with the H3 lysine-79 point mutation indicates that the lysine-to-glutamic acid substitution exerts specific effects within the nucleotide excision repair and post-replication repair pathways, suggesting that this allele only disrupts a subset of the functions of lysine-79 methylation. The overall results indicate the existence of distinct and separable roles of histone H3 lysine-79 methylation in the response to UV damage, potentially serving to coordinate the various repair processes. 相似文献
98.
Tom Albrecht Kamila Opletalov Jií Reif Vclav Janouek Lubomír Pilek Emily R. A. Cramer Arild Johnsen Radka Reifov 《Evolution; international journal of organic evolution》2019,73(2):202-213
Postcopulatory sexual selection may promote evolutionary diversification in sperm form, but the contribution of between‐species divergence in sperm morphology to the origin of reproductive isolation and speciation remains little understood. To assess the possible role of sperm diversification in reproductive isolation, we studied sperm morphology in two closely related bird species, the common nightingale (Luscinia megarhynchos) and the thrush nightingale (Luscinia luscinia), that hybridize in a secondary contact zone spanning Central and Eastern Europe. We found: (1) striking divergence between the species in total sperm length, accompanied by a difference in the length of the mitochondrial sperm component; (2) greater divergence between species in sperm morphology in sympatry than in allopatry, with evidence for character displacement in sperm head length detected in L. megarhynchos; (3) interspecific hybrids showing sperm with a length intermediate between the parental species, but no evidence for decreased sperm quality (the proportion of abnormal spermatozoa in ejaculates). Our results demonstrate that divergence in sperm morphology between the two nightingale species does not result in intrinsic postzygotic isolation, but may contribute to postcopulatory prezygotic isolation. This isolation could be strengthened in sympatry by reinforcement. 相似文献
99.
100.
The phosphatidylethanolamine-binding protein is the prototype of a novel family of serine protease inhibitors 总被引:11,自引:0,他引:11
Serine proteases are involved in many processes in the nervous system and specific inhibitors tightly control their proteolytic activity. Thrombin is thought to play a role in tissue development and homeostasis. To date, protease nexin-1 is the only known endogenous protease inhibitor that specifically interferes with thrombotic activity and is expressed in the brain. In this study, we report the detection of a novel thrombin inhibitory activity in the brain of protease nexin-1(-/-) mice. Purification and subsequent analysis by tandem mass spectrometry identified this protein as the phosphatidylethanolamine-binding protein (PEBP). We demonstrate that PEBP exerts inhibitory activity against several serine proteases including thrombin, neuropsin, and chymotrypsin, whereas trypsin, tissue type plasminogen activator, and elastase are not affected. Since PEBP does not share significant homology with other serine protease inhibitors, our results define it as the prototype of a novel class of serine protease inhibitors. PEBP immunoreactivity is found on the surface of Rat-1 fibroblast cells and although its sequence contains no secretion signal, PEBP-H(6) can be purified from the conditioned medium upon recombinant expression. 相似文献