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61.
Condition, defined as the amount of ‘internal resources’ an individual can freely allocate, is often assumed to be environmentally determined and to reflect an individual’s health and nutritional status. However, an additive genetic component of condition is possible if it ‘captures’ the genetic variance of many underlying traits as many fitness‐related traits appear to do. Yet, the heritability of condition can be low if selection has eroded much of its additive genetic variance, or if the environmental influences are strong. Here, we tested whether feather growth rate – presumably a condition‐dependent trait – has a heritable component, and whether variation in feather growth rate is related to variation in fitness. To this end, we utilized data from a long‐term population study of Siberian jays (Perisoreus infaustus), and found that feather growth rate, measured as the width of feather growth bars (GB), differed between age‐classes and sexes, but was only weakly related to variation in fitness as measured by annual and life‐time reproductive success. As revealed by animal model analyses, GB width was significantly heritable (h2 = 0.10 ± 0.05), showing that this measure of condition is not solely environmentally determined, but reflects at least partly inherited genetic differences among individuals. Consequently, variation in feather growth rates as assessed with ptilochronological methods can provide information about heritable genetic differences in condition. 相似文献
62.
Impact of insect defoliation on forest carbon balance as assessed with a canopy assimilation model 总被引:1,自引:0,他引:1
KARINA V. R. SCHÄFER KENNETH L. CLARK NICHOLAS SKOWRONSKI ERIK P. HAMERLYNCK 《Global Change Biology》2010,16(2):546-560
Disturbances such as fire, hurricanes, and herbivory often result in the net release of CO2 from forests to the atmosphere, but the magnitude of carbon (C) loss is poorly quantified and difficult to predict. Here, we investigate the carbon balance of an oak/pine forest in the New Jersey Pine Barrens using the Canopy Conductance Constrained Carbon Assimilation (4C‐A) model. The 4C‐A model utilizes whole‐tree sap‐flux and leaf‐level photosynthetic gas exchange measurements at distinct canopy levels to estimate canopy assimilation. After model parameterization, sensitivity analyses, and evaluation against eddy flux measurements made in 2006, the model was used to predict C assimilation for an undisturbed year in 2005, and in 2007 when the stand was completely defoliated for 2–3 weeks during an infestation of gypsy moths (Lymantria dispar L.). Following defoliation, only 50% of the foliage reemerged in a second flush. In 2007, canopy net assimilation (AnC), as modeled with the 4C‐A, was reduced to approximately 75% of AnC in 2006 (940 vs. 1240 g C m?2 a?1). Overall, net primary production (NPP) in 2007 was approximately 240 g C m?2 a?1 (vs. 250 g C m?2 a?1 in 2006), with 60% of NPP allocated to foliage production, a short‐term carbon pool. Woody biomass accumulation, a long‐term carbon pool, was reduced by 20% compared with the previous year (72 vs. 57 g C m?2 a?1 in 2006 and 2007, respectively). The overall impact of the defoliation spanned 21% of upland forests (320 km2) in the New Jersey Pine Barrens, representing a significant amount of overall C not being taken up from the atmosphere by the forest, thus not accumulated in the biosphere. 相似文献
63.
Formation of Proteinase Inhibitors in Developing Barley Grain 总被引:1,自引:0,他引:1
MARKKU KIRSI 《Physiologia plantarum》1973,29(2):141-144
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Cajsa Älgenäs Charlotta Agaton Linn Fagerberg Anna Asplund Lisa Björling Erik Björling Caroline Kampf Emma Lundberg Peter Nilsson Anja Persson Kenneth Wester Fredrik Pontén Henrik Wernérus Mathias Uhlén Jenny Ottosson Takanen Sophia Hober 《Biotechnology journal》2014,9(3):435-445
An important concern for the use of antibodies in various applications, such as western blot (WB) or immunohistochemistry (IHC), is specificity. This calls for systematic validations using well‐designed conditions. Here, we have analyzed 13 000 antibodies using western blot with lysates from human cell lines, tissues, and plasma. Standardized stratification showed that 45% of the antibodies yielded supportive staining, and the rest either no staining (12%) or protein bands of wrong size (43%). A comparative study of WB and IHC showed that the performance of antibodies is application‐specific, although a correlation between no WB staining and weak IHC staining could be seen. To investigate the influence of protein abundance on the apparent specificity of the antibody, new WB analyses were performed for 1369 genes that gave unsupportive WBs in the initial screening using cell lysates with overexpressed full‐length proteins. Then, more than 82% of the antibodies yielded a specific band corresponding to the full‐length protein. Hence, the vast majority of the antibodies (90%) used in this study specifically recognize the target protein when present at sufficiently high levels. This demonstrates the context‐ and application‐dependence of antibody validation and emphasizes that caution is needed when annotating binding reagents as specific or cross‐reactive. WB is one of the most commonly used methods for validation of antibodies. Our data implicate that solely using one platform for antibody validation might give misleading information and therefore at least one additional method should be used to verify the achieved data. 相似文献
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J. Nourooz-Zadeh C. G. M. Millar N. K. Gopaul E. E. Änggård 《Redox report : communications in free radical research》2013,18(4):207-211
SummaryF2-isoprostanes are a series of prostaglandin-F2 like compounds specifically derived from peroxidation of arachidonic acid by a mechanism independent of the cyclooxygenase pathway. Of these, 8-epi PGF2α is shown to be a potent vasoconstrictor. In this study, we have analysed plasma 8-epi PGF2α as a marker of oxidative stress in patients with end stage renal failure (ESRF) undergoing haemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Plasma F2-isoprostanes were isolated by solid-phase extraction on a C18 followed by an NH2 cartridge. Quantitative analysis of the F2-isoprostanes as pentafluorobenzyl (PFB) ester/trimethylsilyl (TMS) ether derivatives was carried out by gas chromatography-electron capture mass spectrometry. For 34 individuals with ESRF, the mean level of esterified 8-epi PGF2α was 0.58 ± 0.22 M; range 0.21–1.16 nM. 8-epi PGF2α concentration in the patient groups was markedly higher (P<0.0005 by separate variance t-test) than that of control subjects (n=15) 0.28 ± 0.17 nM; range 0.02–0.63 nM. There was no difference in levels of 8-epi PGF2α in plasma from patients undergoing HD or CAPD, nor was there any association with age, plasma lipids or plasma creatinine. These data provide direct evidence of increased oxidative stress in individuals with ESRF. This marker should be useful in clinical studies examining the degree of oxidative stress in vivo and the therapeutic impact of antioxidants. 相似文献
69.
INA THORMÄHLEN JOACHIM RUBER EDDA VON ROEPENACK‐LAHAYE SVEN‐MATTHIAS EHRLICH VINCENT MASSOT CHRISTINE HÜMMER JUSTYNA TEZYCKA EMMANUELLE ISSAKIDIS‐BOURGUET PETER GEIGENBERGER 《Plant, cell & environment》2013,36(1):16-29
Chloroplast thioredoxin f (Trx f) is an important regulator of primary metabolic enzymes. However, genetic evidence for its physiological importance is largely lacking. To test the functional significance of Trx f in vivo, Arabidopsis mutants with insertions in the trx f1 gene were studied, showing a drastic decrease in Trx f leaf content. Knockout of Trx f1 led to strong attenuation in reductive light activation of ADP‐glucose pyrophosphorylase (AGPase), the key enzyme of starch synthesis, in leaves during the day and in isolated chloroplasts, while sucrose‐dependent redox activation of AGPase in darkened leaves was not affected. The decrease in light‐activation of AGPase in leaves was accompanied by a decrease in starch accumulation, an increase in sucrose levels and a decrease in starch‐to‐sucrose ratio. Analysis of metabolite levels at the end of day shows that inhibition of starch synthesis was unlikely due to shortage of substrates or changes in allosteric effectors. Metabolite profiling by gas chromatography–mass spectrometry pinpoints only a small number of metabolites affected, including sugars, organic acids and ethanolamine. Interestingly, metabolite data indicate carbon shortage in trx f1 mutant leaves at the end of night. Overall, results provide in planta evidence for the role played by Trx f in the light activation of AGPase and photosynthetic carbon partitioning in plants. 相似文献
70.
W. THEUNIS S. BLÄHSER R. HUYBRECHTS A. DE LOOF 《Invertebrate reproduction & development.》2013,57(1-3):111-117
Summary Materials immunologically related to luteinising hormone (LH), follicle stimulating hormone (FSH) and the gonadotropin releasing hormone (GnRH) were localised in cerebral tissue of Locusta migratoria and Sarcophaga bullata by means of the peroxidase-antiperoxidase method. Several polyclonal and a monoclonal antisera were used. From the third larval instar a positive reaction was observed in cells located in several parts of the brain. Each antiserum reacted with a constant number of well defined cells and nerve fibers. No differences between sexes were observed. 相似文献