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1.
Arctic seas have warmed and sea ice has retreated. This has resulted in range contraction and population declines in some species, but it could potentially be a boon for others. Great Cormorants Phalacrocorax carbo have a partially wettable plumage and seem poorly suited to foraging in Arctic waters. We show that rates of population change of Cormorant colonies around Disko Bay, Greenland, are positively correlated with sea surface temperature, suggesting that they may benefit from a warming Arctic. However, although Cormorant populations may increase in response to Arctic warming, the extent of expansion of their winter range may ultimately be limited by other factors, such as sensory constraints on foraging behaviour during long Arctic nights.  相似文献   
2.
Calanus finmarchicus is a key‐structural species of the North Atlantic polar biome. The species plays an important trophic role in subpolar and polar ecosystems as a grazer of phytoplankton and as a prey for higher trophic levels such as the larval stages of many fish species. Here, we used a recently developed ecological niche model to assess the ecological niche (sensu Hutchinson) of C. finmarchicus and characterize its spatial distribution. This model explained about 65% of the total variance of the observed spatial distribution inferred from an independent dataset (data of the continuous plankton recorder survey). Comparisons with other types of models (structured population and ecophysiological models) revealed a clear similarity between modeled spatial distributions at the scale of the North Atlantic. Contemporary models coupled with future projections indicated a progressive reduction of the spatial habitat of the species at the southern edge and a more pronounced one in the Georges Bank, the Scotian Shelf and the North Sea and a potential increase in abundance at the northern edge of its spatial distribution, especially in the Barents Sea. These major changes will probably lead to a major alteration of the trophodynamics of North Atlantic ecosystems affecting the trophodynamics and the biological carbon pump.  相似文献   
3.

Background

Since the first fungal genome sequences became available, investigators have been employing comparative genomics to understand how fungi have evolved to occupy diverse ecological niches. The secretome, i.e. the entirety of all proteins secreted by an organism, is of particular importance, as by these proteins fungi acquire nutrients and communicate with their surroundings.

Results

It is generally assumed that fungi with similar nutritional lifestyles have similar secretome compositions. In this study, we test this hypothesis by annotating and comparing the soluble secretomes, defined as the sets of proteins containing classical signal peptides but lacking transmembrane domains of fungi representing a broad diversity of nutritional lifestyles. Secretome size correlates with phylogeny and to a lesser extent with lifestyle. Plant pathogens and saprophytes have larger secretomes than animal pathogens. Small secreted cysteine-rich proteins (SSCPs), which may comprise many effectors important for the interaction of plant pathogens with their hosts, are defined here to have a mature length of ≤ 300 aa residues, at least four cysteines, and a total cysteine content of ≥5%. SSCPs are found enriched in the secretomes of the Pezizomycotina and Basidiomycota in comparison to Saccharomycotina. Relative SSCP content is noticeably higher in plant pathogens than in animal pathogens, while saprophytes were in between and closer to plant pathogens. Expansions and contractions of gene families and in the number of occurrences of functional domains are largely lineage specific, e.g. contraction of glycoside hydrolases in Saccharomycotina, and are only weakly correlated with lifestyle. However, within a given lifestyle a few general trends exist, such as the expansion of secreted family M14 metallopeptidases and chitin-binding proteins in plant pathogenic Pezizomycotina.

Conclusions

While the secretomes of fungi with similar lifestyles share certain characteristics, the expansion and contraction of gene families is largely lineage specific, and not shared among all fungi of a given lifestyle.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-722) contains supplementary material, which is available to authorized users.  相似文献   
4.
Acetic acid hydrazide containing 5-methyl-2-benzoxazolinone (4) was synthesized by the condensation of 2-(5-methyl-2-benzoxazolinone-3-yl)acetate with hydrazine hydrate. Thiosemicarbazide derivatives (5a-5d) were afforded by the reaction of corresponding compound 4 with substituted isothiocyanates. The cyclization of compounds 5a-5d in the presence of triethylamine resulted in the formation of compounds 6a-6d containing 1,2,4-triazole ring. On the other hand, the treatment of compounds 5a-5d with orthophosphoric acid caused the conversion of side chain of compounds 5a-5d into 1,3,4-thiadiazole ring: thus, compounds 7a-7c were obtained. The treatment of compound 4 with aromatic aldehydes resulted in the formation of arylidene hydrazides as cis-trans conformers (8a-8e). The structures of the compounds were elucidated by spectral and elemental analysis. While most compounds were exhibiting high activity in the analgesic-anti-inflammatory field, most of them were found to be inactive against bacteria and fungi.  相似文献   
5.
A DNA aptamer specific for Thermus aquaticus DNA polymerase (Taq-polymerase) was immobilized on magnetic beads, which were prepared in the presented study. The effect of various parameters including pH, temperaturem and aptamer concentration on the immobilization of 5'-thiol labeled DNA-aptamer onto glutaric dialdhyde activated magnetic beads was evaluated. The binding conditions of Taq-polymerase on the aptamer immobilized magnetic beads were studied using commercial Taq-polymerase to characterize the surface complexation reaction. Efficiency of affinity magnetic beads in the purification of recombinant Taq-polymerase from crude extracts was also evaluated. For this case, the enzyme "recombinant Taq-DNA polymerase" was cloned and expressed using an Amersham E. coli GST-Gene Fusion Expression system. Crude extracts were in contact with affinity magnetic beads for 30 min and were collected by magnetic field application. The purity of the eluted Tag-polymerase from the affinity beads, as determined by HPLC, was 93% with a recovery of 89% in a one-step purification protocol. Apparently, the system was found highly effective as one step for the low-cost purification of Taq-polymerase in bacterial crude extract.  相似文献   
6.
7.
We have developed a novel and versatile three-dimensional cellular automaton model of brain tumor growth. We show that macroscopic tumor behavior can be realistically modeled using microscopic parameters. Using only four parameters, this model simulates Gompertzian growth for a tumor growing over nearly three orders of magnitude in radius. It also predicts the composition and dynamics of the tumor at selected time points in agreement with medical literature. We also demonstrate the flexibility of the model by showing the emergence, and eventual dominance, of a second tumor clone with a different genotype. The model incorporates several important and novel features, both in the rules governing the model and in the underlying structure of the model. Among these are a new definition of how to model proliferative and non-proliferative cells, an isotropic lattice, and an adaptive grid lattice.  相似文献   
8.
Chromosomal mosaicism in prenatal diagnosis is an important problem to be solved immediately and the probable phenotypic reflections should be explained to the family. We report two numerical and two structural mosaicisms detected in amniocyte cultures. The first fetus had a 47,XY,+mar[10]/46,XY[10] karyotype. The marker chromosome was shown to be derived from chromosome 15 by FISH method. The newborn had intrauterine growth retardation and cerebral thrombosis and died at the 29th day of age. The second fetus had a 45,X[4]/46,XX[26] karyotype. The parents refused cordocentesis and decided to terminate pregnancy in the 21st week. The third case, presented with bilateral large choroid plexus cysts, had a 46,XX, dup(1)(q22-q32)[9]/46,XX[21] karyotype. The parents' karyotypes were normal and the pregnancy was aborted in the 23rd week of gestation. The second structural abnormality was reported as 46,XX,t(6;11)(q23; p13)[3]/46,XX[20]. The mosaicism was detected in only one flask. The parents decided to continue pregnancy and cordocentesis could not be performed due to the fetal and placental position. The baby was born at term. Peripheral blood lymphocyte culture resulted in a 46,XX normal karyotype. Information and risks were explained to all families during genetic counseling. Mosaicism in prenatal diagnosis needs both detailed examination and follow up, since clinical findings depend on the type of abnormality.  相似文献   
9.
10.
Role of the tubulin-microtubule system in lymphocyte activation   总被引:3,自引:2,他引:1       下载免费PDF全文
The role of the tubulin-microtubule system was examined in human peripheral blood leukocytes after activation with phytohemagglutinin (PHA). Soluble tubulin and microtubules were measured with a [(3)H]colchicine-binding assay. It was found that the tubulin content of PHA-activated lymphocytes was consistently increased relative to total protein content after 36 h of culture. There was no increase in the proportion of total tubulin synthesis which was present as microtubules at 36 h. Nevertheless, as a result of increased tubulin synthesis, there was a two-to three-fold increase in total microtubular mass. Colchicine, which disrupts microtubles, was used to assess the role of microtubule assembly in the sequence of events which follow lymphocyte activation, namely lymphokine release, protein synthesis, RNA synthesis, and DNA synthesis. Colchicine consistently inhibited DNA synthesis but did not inhibit release of the lymphokine, osteoclast activating factor (OAF). Protein and RNA syntheses were inhibited much less than DNA synthesis. The fact that some effects of PHA on lymphocytes appear to require intact microtubules and at least one does not suggest that the microtubule dependent step in PHA-stimulated lymphocyte activation occurs at a stage after propagation of the signal from the membrane to the cell interior.  相似文献   
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