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1.
Systematics and taxonomy of hares of the genus Lepus (Lagomorpha) are under contentious debate, and phylogenetic relationships among many taxa are not well understood. Here we study genetic differentiation and evolutionary relationships among North African hares, currently considered subspecies of Lepus capensis , cape hares ( L. capensis ) from the Cape province in South Africa, and brown hares ( L. europeaus ) from Europe and Anatolia, using maternally (mtDNA) and biparentally (allozymes) inherited markers. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of a c. 1.8 kb long segment of the mitochondrial control region using eight hexanucleotide-recognizing restriction endonucleases yielded 28 haplotypes, and horizontal starch gel electrophoresis of proteins encoded by 25 structural gene loci revealed 52 alleles at 18 polymorphic loci. Diverse phylogenetic analyses (neighbor joining dendrogram, median joining network, multidimensional scaling of pairwise distances, AMOVA, F -statistics, hierarchical F -statistics) of genetic variants revealed marked substructuring of mtDNA into three phylogeographic groups, namely an African, a central European, and an Anatolian, but a somewhat less pronounced overall differentiation of the nuclear genome, despite a relatively high number of population-specific (private) alleles. However, all our results are not incongruent with Petter's (1959: Mammalia 23 , 41; 1961: Z. f. Säugetierkunde 26 , 30; 1972 : Société Des Sciences Naturelles et Physiques du Maroc 52 , 122) hypothesis that North African hares generally belong to L. capensis and that brown hares should be included in this species as well.  相似文献   
2.
The effect of Bombyx mori nuclear polyhedrosis virus (BmNPV) on biochemical changes of TC-100 medium containing 10% fetal bovine serum (FBS) in embryonic primary cultures of silkworm was investigated. The primary cultures that reached 60% confluence were infected by 0.5, 1, and 2-ml viral inoculums (diluted with TC-100 medium representing multiplicity of infection (MOI) of 0.25, 0.5, and 1). Glucose, uric acid, urea, total protein, cholesterol, and alkaline phosphatase were measured in the medium of BmNPV-infected primary cultures. All biochemical compounds showed significant changes. Glucose decreased considerably by about 55 mg/ml, while different concentrations of the virus inoculums did not demonstrate significant differences among them. Total protein had only increased in 2 ml concentration and there were no changes in other concentrations. Uric acid as a by-product accumulated dramatically in all concentrations, while the amount of urea reduced in all treatments and this reduction was more evident in lower concentrations. Cholesterol consumption was high in cultures postinfection, while alkaline phosphatase (ALP) activity decreased in infected cells.  相似文献   
3.
Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) plays a critical role in sustaining life by catalysis of carbon fixation in the Calvin–Benson pathway. Incomplete knowledge of the assembly pathway of chloroplast Rubisco has hampered efforts to fully delineate the enzyme's properties, or seek improved catalytic characteristics via directed evolution. Here we report that a Mu transposon insertion in the Zea mays (maize) gene encoding a chloroplast dimerization co‐factor of hepatocyte nuclear factor 1 (DCoH)/pterin‐4α‐carbinolamine dehydratases (PCD)‐like protein is the causative mutation in a seedling‐lethal, Rubisco‐deficient mutant named Rubisco accumulation factor 2 (raf21). In raf2 mutants newly synthesized Rubisco large subunit accumulates in a high‐molecular weight complex, the formation of which requires a specific chaperonin 60‐kDa isoform. Analogous observations had been made previously with maize mutants lacking the Rubisco biogenesis proteins RAF1 and BSD2. Chemical cross‐linking of maize leaves followed by immunoprecipitation with antibodies to RAF2, RAF1 or BSD2 demonstrated co‐immunoprecipitation of each with Rubisco small subunit, and to a lesser extent, co‐immunoprecipitation with Rubisco large subunit. We propose that RAF2, RAF1 and BSD2 form transient complexes with the Rubisco small subunit, which in turn assembles with the large subunit as it is released from chaperonins.  相似文献   
4.
Lectins have been classified into a structurally diverse group of proteins that bind carbohydrates and glycoconjugates with high specificity. They are extremely useful molecules in the characterization of saccharides, as drug delivery mediators, and even as cellular surface makers. In this study, we present camptosemin, a new lectin from Camptosema ellipticum. It was characterized as an N-acetyl-d-galactosamine-binding homo-tetrameric lectin, with a molecular weight around 26 kDa/monomers. The monomers were stable over a wide range of pH values and exhibited pH-dependent oligomerization. Camptosemin promoted adhesion of breast cancer cells and hemagglutination, and both activities were inhibited by its binding of sugar. The stability and unfolding/folding behavior of this lectin was characterized using fluorescence and far-UV circular dichroism spectroscopies. The results indicate that chemical unfolding of camptosemin proceeds as a two-state monomer-tetramer process. In addition, small-angle X-ray scattering shows that camptosemin behaves as a soluble and stable homo-tetramer molecule in solution.  相似文献   
5.
In order to identify factors affecting cationic Iiposome-mediated gene transfer, the relationships were examined among cationic liposome/DNA complex (lipoplex)-cell interactions, lipoplex size and lipoplex-mediated transfection (lipofection) efficiency. It was found that lipofection efficiency was determined mainly by lipoplex size, but not by the extent of lipoplex-cell interactions including binding, uptake or fusion. In addition, it was found that serum affected mainly lipoplex size, but not lipoplex-cell interactions, which effect was the major reason behind the inhibitory effect of serum on lipofection efficiency. It was concluded that, in the presence or absence of serum, lipoplex size is a major factor determining Iipofection efficiency. Moreover, in the presence or absence of serum, lipoplex size was found to affect lipofection efficiency by controlling the size of the intracellular vesicles containing lipoplexes after internalization, but not by affecting lipoplex-cell interactions. In addition, large lipoplex particles showed, in general, higher lipofection efficiency than small particles. These results imply that, by controlling lipoplex size, an efficient lipid delivery system may be achieved for in vitro and in vivo gene therapy.  相似文献   
6.
Senescence and autophagy play important roles in homeostasis. Cellular senescence and autophagy commonly cause several degenerative processes, including oxidative stress, DNA damage, telomere shortening, and oncogenic stress; hence, both events are known to be interrelated. Autophagy is well known for its disruptive effect on human diseases, and it is currently proposed to have a direct effect on triggering senescence and quiescence. However, it is yet to be proven whether autophagy has a positive or negative impact on senescence. It is known that elevated levels of autophagy induce cell death, whereas inadequate autophagy can trigger cellular senescence. Both have important roles in human diseases such as aging, renal degeneration, neurodegenerative disorders, and cancer. Therefore, this review aims to highlight the relevance of senescence and autophagy in selected human ailments through a summary of recent findings on the connection and effects of autophagy and senescence in these diseases.  相似文献   
7.
Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic pathogen capable of causing severe respiratory disease in humans. Although dromedary camels are considered as a major reservoir host, the MERS-CoV infection dynamics in camels are not fully understood. Through surveillance in Pakistan, nasal (n = 776) and serum (n = 1050)samples were collected from camels between November 2015 and February 2018. Samples were collected from animal markets, free-roaming herds and abattoirs. An in-house ELISA was developed to detect IgG against MERS-CoV. A total of 794 camels were found seropositive for MERS-CoV. Prevalence increased with the age and the highest seroprevalence was recorded in camels aged [ 10 years (81.37%) followed by those aged 3.1–10 years (78.65%) and B 3 years (58.19%).Higher prevalence was observed in female (78.13%) as compared to male (70.70%). Of the camel nasal swabs, 22 were found to be positive by RT-qPCR though with high Ct values. Moreover, 2,409 human serum samples were also collected from four provinces of Pakistan during 2016–2017. Among the sampled population, 840 humans were camel herders.Although we found a high rate of MERS-CoV antibody positive dromedaries (75.62%) in Pakistan, no neutralizing antibodies were detected in humans with and without contact to camels.  相似文献   
8.
9.
The question which bacterial species are present in water and if they are viable is essential for drinking water safety but also of general relevance in aquatic ecology. To approach this question we combined propidium iodide/SYTO9 staining (“live/dead staining” indicating membrane integrity), fluorescence-activated cell sorting (FACS) and community fingerprinting for the analysis of a set of tap water samples. Live/dead staining revealed that about half of the bacteria in the tap water had intact membranes. Molecular analysis using 16S rRNA and 16S rRNA gene-based single-strand conformation polymorphism (SSCP) fingerprints and sequencing of drinking water bacteria before and after FACS sorting revealed: (1) the DNA- and RNA-based overall community structure differed substantially, (2) the community retrieved from RNA and DNA reflected different bacterial species, classified as 53 phylotypes (with only two common phylotypes), (3) the percentage of phylotpes with intact membranes or damaged cells were comparable for RNA- and DNA-based analyses, and (4) the retrieved species were primarily of aquatic origin. The pronounced difference between phylotypes obtained from DNA extracts (dominated by Betaproteobacteria, Bacteroidetes, and Actinobacteria) and from RNA extracts (dominated by Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, and Cyanobacteria) demonstrate the relevance of concomitant RNA and DNA analyses for drinking water studies. Unexpected was that a comparable fraction (about 21%) of phylotypes with membrane-injured cells was observed for DNA- and RNA-based analyses, contradicting the current understanding that RNA-based analyses represent the actively growing fraction of the bacterial community. Overall, we think that this combined approach provides an interesting tool for a concomitant phylogenetic and viability analysis of bacterial species of drinking water.  相似文献   
10.
Protein kinase D (PKD), also called protein kinase C (PKC)mu, is a serine-threonine kinase that is involved in diverse areas of cellular function such as lymphocyte signaling, oxidative stress, and protein secretion. After identifying a putative PKD phosphorylation site in the Toll/IL-1R domain of TLR5, we explored the role of this kinase in the interaction between human TLR5 and enteroaggregative Escherichia coli flagellin in human epithelial cell lines. We report several lines of evidence that implicate PKD in TLR5 signaling. First, PKD phosphorylated the TLR5-derived target peptide in vitro, and phosphorylation of the putative target serine 805 in HEK 293T cell-derived TLR5 was identified by mass spectrometry. Furthermore, mutation of serine 805 to alanine abrogated responses of transfected HEK 293T cells to flagellin. Second, TLR5 interacted with PKD in coimmunoprecipitation experiments, and this association was rapidly enhanced by flagellin treatment. Third, pharmacologic inhibition of PKC or PKD with G?6976 resulted in reduced expression and secretion of IL-8 and prevented the flagellin-induced activation of p38 MAPK, but treatment with the PKC inhibitor G?6983 had no significant effects on these phenotypes. Finally, involvement of PKD in the p38-mediated IL-8 response to flagellin was confirmed by small hairpin RNA-mediated gene silencing. Together, these results suggest that phosphorylation of TLR5 by PKD may be one of the proximal elements in the cellular response to flagellin, and that this event contributes to p38 MAPK activation and production of inflammatory cytokines in epithelial cells.  相似文献   
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