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1.
Ewa A. Czy Carla Guilln Escrib Hendrik Wulf Andrew Tedder Meredith C. Schuman Fabian D. Schneider Michael E. Schaepman 《Ecology and evolution》2020,10(14):7419-7430
- The growing pace of environmental change has increased the need for large‐scale monitoring of biodiversity. Declining intraspecific genetic variation is likely a critical factor in biodiversity loss, but is especially difficult to monitor: assessments of genetic variation are commonly based on measuring allele pools, which requires sampling of individuals and extensive sample processing, limiting spatial coverage. Alternatively, imaging spectroscopy data from remote platforms may hold the potential to reveal genetic structure of populations. In this study, we investigated how differences detected in an airborne imaging spectroscopy time series correspond to genetic variation within a population of Fagus sylvatica under natural conditions.
- We used multi‐annual APEX (Airborne Prism Experiment) imaging spectrometer data from a temperate forest located in the Swiss midlands (Laegern, 47°28'N, 8°21'E), along with microsatellite data from F. sylvatica individuals collected at the site. We identified variation in foliar reflectance independent of annual and seasonal changes which we hypothesize is more likely to correspond to stable genetic differences. We established a direct connection between the spectroscopy and genetics data by using partial least squares (PLS) regression to predict the probability of belonging to a genetic cluster from spectral data.
- We achieved the best genetic structure prediction by using derivatives of reflectance and a subset of wavebands rather than full‐analyzed spectra. Our model indicates that spectral regions related to leaf water content, phenols, pigments, and wax composition contribute most to the ability of this approach to predict genetic structure of F. sylvatica population in natural conditions.
- This study advances the use of airborne imaging spectroscopy to assess tree genetic diversity at canopy level under natural conditions, which could overcome current spatiotemporal limitations on monitoring, understanding, and preventing genetic biodiversity loss imposed by requirements for extensive in situ sampling.
2.
3.
A robust method for selection of variables with the greatest discriminatory power is presented in the paper. The method deals with the two groups of data problem. An application of the method to some respiratory disease data and comparisons with classical procedures are given, also. 相似文献
4.
P. Mark Hogarth Margaret L. Hibbs Lisa Bonadonna Bernadette M. Scott Ewa Witort Geoffrey A. Pietersz Ian F. C. McKenzie 《Immunogenetics》1987,26(3):161-168
A cDNA clone encoding the mouse Ly-17+ Fc receptor for IgG, isolated from a myelomonocytic cell line, was sequenced and expression of mRNA and the functional FcR investigated. The receptor is a 301 amino acid transmembrane glycoprotein with two homologous extracellular domains that are also homologous to members of the Ig superfamily. The receptor has four sites of N-linked glycosylation and a long 94 amino acid cytoplasmic tail. Northern analysis, immune complex binding, and serological studies demonstrate that the receptor encoded by the cDNA clone binds mouse IgG1/2b and rabbit IgG complexes. 相似文献
5.
Pertussis toxin inhibits CAMP-induced desensitization of adenylate cyclase in Dictyostelium discoideum 总被引:2,自引:0,他引:2
B. Ewa Snaar-Jagalska Peter J. M. Van Haastert 《Molecular and cellular biochemistry》1990,92(2):177-189
cAMP binds to surface receptors of Dictyostelium discoideum cells, transducing the signal to adenylate cyclase, guanylate cyclase and to chemotaxis. The activation of adenylate cyclase is maximal after 1 min and then declines to basal levels due to desensitization, which is composed of two components: a rapidly reversible adaptation process, and a slowly reversible down-regulation of cAMP receptors. Adaptation is correlated with receptor phosphorylation.The chemotactic response and the cAMP-induced cGMP response were not significantly altered in D. discoideum cells pretreated with pertussis toxin. The initial increase of cAMP levels was identical in control and toxin treated cells, suggesting that activation of adenylate cyclase was also not affected. However, cAMP synthesis continued in toxin treated cells, due to a strongly diminished desensitization. Pertussis toxin inhibited the adaptation of adenylate cyclase stimulation, but not the down-regulation or phosphorylation of the cAMP receptors. Adenylate cyclase in D. discoideum membranes can be stimulated or inhibited by GTP, depending on the conditions used. Pertussis toxin did not affect the stimulation of adenylate cyclase but nullified the inhibition. In membranes from desensitized control cells, stimulation of adenylate cyclase by GTP was lost, whereas inhibition was retained. Stimulation of adenylate cyclase in membranes from desensitized pertussis toxin treated cells was diminished but not absent. These results indicate that receptor phosphorylation is not sufficient for adaptation of adenylate cyclase, and that a pertussis toxin substrate, possibly Gi, is also involved in this process.Abbreviations used ATPS
Adenosine 5-0-(3-Thiotriphosphate)
- GTPS
Guanosine 5-0-(3-thiotri-phosphate)
- (Sp)-cAMPS
Adenosine 3,5-monophosphorothioate-Sp-isomer
- dcAMP
2-deoxyadenosine 3,5-monophosphate
- Hepes
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- DTT
Dithiothreitol
- buffer A
10 mM KH2PO4/Na2HPO4, pH 6.5
- buffer B
40 mM Hepes/NaOH, 0.5 mM EDTA, 250 mM sucrose, pH 7.7 相似文献
6.
We describe a technique for rapidly screening the inserts of plasmids for homology to each other by using DNA fragments isolated in agarose gels to probe Southern blots of DNA prepared by the "miniprep" alkaline lysis method. The procedure includes a technique for labeling DNA fragments in agarose gel slices without further purification. The protocol results in a significant savings in time and expense and a considerable increase in fragment yield over methods involving fragment purification from polyacrylamide or agarose gels. 相似文献
7.
Robert A. Holt Andrew J. Cairns J. Gareth Morris 《Applied microbiology and biotechnology》1988,27(4):319-324
Summary The pink-pigmented, amylolytic and pectinolytic bacterium Clostridium puniceum in anaerobic batch culture at pH 5.5 and 25–30°C produced butan-1-ol as the major product of fermentation of glucose or starch. The alcohol was formed throughout the exponential phase of growth and surprisingly little acetone was simultaneously produced. Furthermore, acetic and butyric acids were only accumulated in low concentrations, and under optimal conditions were completely re-utilised before the fermentation ceased. Thus, in a minimal medium containing 4% w/v glucose as sole source of carbon and energy, after 65 h at 25°C, pH 5.5 all of the glucose had been consumed to yield (g product/100 g glucose utilised) butanol 32, acetone 3 and ethanol 2. Butanol was again the major product of glucose fermentation during phosphate-limited chemostat culture wherein, although the organism eventually lost its capacity to sporulate and to synthesize granulose, production of butanol continued for at least 100 volume changes. Under no growth condition was the organism capable of producing more than 13.3 g l-1 of butanol. At pH 5.5, growth on pectin was slow and yielded a markedly lesser biomass concentration than when growth was on glucose or starch; acetic acid was the major fermentation product with lower concentrations of methanol, acetone, butanol and butyric acid. At pH 7, growth on all substrates produced virtually no solvents but high concentrations of both acetic and butyric acids. 相似文献
8.
The germination of Amaranthus paniculatus seeds was inhibited by applying paclobutrazol, a specific inhibitor of gibberellin biosynthesis. This inhibition was markedly counteracted by gibberellin A3 (GA3), suggesting that endogenous gibberellins are required for germination in this species. The inhibitory effect of paclobutrazol was also overcome by ethephon (2-chloroethylphosphonic acid) or the precursor of ethylene biosynthesis, ACC (1-aminocyclopropane-l-carboxylic acid). Thus the physiological effect of gibberellin can be mimicked by ethylene released from ethephon or synthesised from exogenous ACC. It is suggested, that endogenous gibberellins are involved in germination of Amaranthus paniculatus seeds and that action of GA3 can be substituted by ethylene.Abbreviations ACC
1-aminocyclopropane-l-carboxylic acid
- AMO-1618
(2-isopropyl-5methyl-4-trimethylammoniumchloride)-phenyl-l-piperidinium-carboxylate
- ancymidol
-cyclopropyl--(4-methoxyphenyl)-5-pyrimidine methanol
- chloromequat chloride
(2-chloroethyl)trimethylammoniumchloride
- ethephon
2-chloroethylphosphonic acid
- GA
gibberellin A3
- paclobutrazol
(2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-lyl)pentan-3-ol
- Phosphon D
2,4,dichlorobenzyl-tributhylphosphoniumchloride
- tetcyclacis
5,(4-chlorophenyl)-3,4,5,9,10-pentaaza-tetracyclo)5,4,1,0,Z,6,08,11 dodeca-3,9-diene 相似文献
9.
Piotr Borsuk Marek Gniadkowski Ewa Bartnik Piotr P. Stępień 《Journal of molecular evolution》1988,28(1-2):125-130
Summary AllAspergillus nidulans 5S rRNA pseudogenes known so far are the result of integration of an approx. 0.2-kbp-long DNA sequence into the 5S rRNA genes. This sequence, called block C, is present in at least five copies in theA. nidulans genome and seems to be associated either with 5S rRNA genes or pseudogenes. In contrast to the 78% sequence conservation of the C-block in pseudogenes, the truncated 5 halves of the pseudogenes are very highly conserved (96.9–100%). We postulate that the 5S rRNA pseudogenes are still a subject of concerted evolution. The C-block sequence shows similarity to the switch region of the mouse heavy chain immunoglobulin gene. A characteristic motif GGGTGAG is repeated several times in both sequences; the sequence conservation is 63%. 相似文献
10.
Our objective was to examine the developmental fate of sperm nuclei in oocytes fertilized under conditions of meiotic arrest. Therefore zona-free metaphase II oocytes and oocyte fragments (nucleate and anucleate) were fertilized in the presence of colcemid. In anucleate oocyte fragments, normal male pronuclei develop. In contrast, in intact oocytes and nucleate fragments sperm nuclei after initial decondensation undergo secondary condensation. This state is maintained as long as the oocytes are treated with colcemid. When the drug is removed 3 h after insemination, the meiotic spindle(s) is reconstructed, the second polar body(ies) is extruded, and a female pronucleus (or micronuclei) forms. At the same time the sperm nucleus decondenses again and transforms into a male pronucleus. In addition oocytes fertilized in the presence of colcemid could not be refertilized. These observations suggest that oocytes and oocyte fragments fertilized in the presence of colcemid undergo activation despite the failure of pronucleus formation. The inhibitory effect of colcemid on the formation of pronuclei is expressed only in the presence of oocyte chromosomes. We suggest that colcemid stabilizes factors responsible for chromosome condensation that are associated with oocyte chromosomes but not factors (whether the same or different) present in the cytoplasm. 相似文献