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131.
Nexø BA Christensen T Frederiksen J Møller-Larsen A Oturai AB Villesen P Hansen B Nissen KK Laska MJ Petersen TS Bonnesen S Hedemand A Wu T Wang X Zhang X Brudek T Maric R Søndergaard HB Sellebjerg F Brusgaard K Kjeldbjerg AL Rasmussen HB Nielsen AL Nyegaard M Petersen T Børglum AD Pedersen FS 《PloS one》2011,6(2):e16652
We have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease. The latter association was limited to a narrow region that contains no other known genes. We conclude that HERV-Fc1 and TRIM5 play a role in the etiology of multiple sclerosis. If these results are confirmed, they point to new modes of treatment for multiple sclerosis. 相似文献
132.
The 18.8 kDa chitin-binding protein CBP21 from Serratia marcescens has been isotopically labeled and recombinantly expressed. In this paper, we report the 1H, 13C, 15N resonance assignment of CBP21. 相似文献
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Finn Salomonsen 《Journal of Ornithology》1941,89(2-3):282-337
Ohne Zusammenfassung 相似文献
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The causes of variation in the presence of genetic covariance between sexual traits and preferences
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Kasey D. Fowler‐Finn Rafael L. Rodríguez 《Biological reviews of the Cambridge Philosophical Society》2016,91(2):498-510
Mating traits and mate preferences often show patterns of tight correspondence across populations and species. These patterns of apparent coevolution may result from a genetic association between traits and preferences (i.e. trait–preference genetic covariance). We review the literature on trait–preference covariance to determine its prevalence and potential biological relevance. Of the 43 studies we identified, a surprising 63% detected covariance. We test multiple hypotheses for factors that may influence the likelihood of detecting this covariance. The main predictor was the presence of genetic variation in mate preferences, which is one of the three main conditions required for the establishment of covariance. In fact, 89% of the nine studies where heritability of preference was high detected covariance. Variables pertaining to the experimental methods and type of traits involved in different studies did not greatly influence the detection of trait–preference covariance. Trait–preference genetic covariance appears to be widespread and therefore represents an important and currently underappreciated factor in the coevolution of traits and preferences. 相似文献
139.
Dinitrogen fixation in white clover (Trifolium repens L.) grown in pure stand and mixture with perennial ryegrass (Lolium
perenne L.) was determined in the field using 15N isotope dilution and harvest of the shoots. The apparent transfer of clover N to perennial ryegrass was simultaneously assessed.
The soil was labelled either by immobilizing 15N in organic matter prior to establishment of the sward or by using the conventional labelling procedure in which 15N fertilizer is added after sward establishment. Immobilization of 15N in the soil organic matter has not previously been used in studies of N2 fixation in grass/clover pastures. However, this approach was a successful means of labelling, since the 15N enrichment only declined at a very slow rate during the experiment. After the second production year only 10–16% of the
applied 15N was recovered in the harvested herbage. The two labelling methods gave, nonetheless, a similar estimate of the percentage
of clover N derived from N2 fixation. In pure stand clover, 75–94% of the N was derived from N2 fixation and in the mixture 85–97%. The dry matter yield of the clover in mixture as percentage of total dry matter yield
was relatively high and increased from 59% in the first to 65% in the second production year. The average daily N2 fixation rate in the mixture-grown clover varied from less than 0.5 kg N ha−1 day−1 in autumn to more than 2.6 kg N ha−1 day−1 in June. For clover in pure stand the average N2 fixation rate was greater and varied between 0.5 and 3.3 kg N ha−1 day−1, but with the same seasonal pattern as for clover in mixture. The amount of N fixed in the mixture was 23, 187 and 177 kg
N ha−1 in the seeding, first and second production year, respectively, whereas pure stand clover fixed 28, 262 and 211 kg N ha−1 in the three years. The apparent transfer of clover N to grass was negligible in the seeding year, but clover N deposited
in the rhizosphere or released by turnover of stolons, roots and nodules, contributed 19 and 28 kg N ha−1 to the grass in the first and second production year, respectively.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
140.
Vitamin K uptake in hepatocytes and hepatoma cells 总被引:1,自引:0,他引:1
Hepatocellular carcinoma (HCC) or hepatoma cells have impaired ability to perform vitamin K-dependent carboxylation reactions. Vitamin K can also inhibit growth of HCC cells in vitro. Both carboxylation and growth inhibition are vitamin K dose dependent. We used rat hepatocytes, a vitamin K-growth sensitive (MH7777) and a vitamin K-growth resistant (H4IIE) rat hepatoma cell line to examine vitamin K uptake and vitamin K-mediated microsomal carboxylation. We found that vitamin K is taken up by normal rat hepatocytes against a saturable concentration gradient. The relative rates of uptake by rat hepatocytes and the two rat cell lines MH7777 and H4IIE correlated with their sensitivity to vitamin K-mediated cell growth inhibition. Pooled hepatocytes from liver nodules from rats treated with the hepatocarcinogen diethylnitrosamine (DEN) also had a reduced rate of vitamin K uptake. However, using a cell-free system, microsomes from both normal rat hepatocytes and the two rat hepatoma cell lines had a similar ability to support carboxylation mediated by exogenously added vitamin K. The results support the hypothesis that different sensitivity of hepatoma cells to vitamin K may be due to differences in vitamin K uptake and may be unrelated to the actions of vitamin K on carboxylation. 相似文献