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1.
Chromosome counts of the following 15 taxa are given:Eupatorium cannabinum, Gypsophila fastigiata, Helianthemum grandiflorum subsp.obscurum, Helictotrichon desertorum subsp.basalticum, Impatiens parviflora, Inula hirta, Jurinea mollis, Kernera saxatilis, Lembotropis nigricans subsp.nigricans, Malva alcea subsp.excisa, Myosotis nemorosa, Otites pseudotites subsp.cuneifolia, Plantago atrata subsp.carpatica, P. atrata subsp.sudetica, Poa badensis. The chromosome numbers ofHelictotrichon desertorum (as subsp.basalticum) andPlantago atrata subsp.sudetica are given for the first time. Chromosome numbers differing from those previously known were found inJurinea mollis (2n=34 as compared to 2n=30) andKernera saxatilis (2n=14 as compared to 2n=16).Rhodax Spach (=Helianthemum L. p. p.) andOtites Adans. (=Silene L. p. p.) are considered as separate genera. Remarks on taxonomy, nomenclature and chorology are given for most of the taxa.  相似文献   

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《Plant science》1988,55(3):223-230
Pathogeneis-related (PR) proteins are induced in plants in response to a variety of pathogenic and chemical agents, in natural senescence and during the onset of flowering. Although the function of these proteins is unknown, they have been proposed to play a central role in plant resistance mechanisms.In this paper we present the immunocytochemical localization of P1(p14), the most abundant PR protein of tomato plants. Our results show the association of this protein with disorganized cytosol material. This material has been found in parenchyma leaf tissue from healthy (non-infected) tomato plants, either in cells under disorganization or in the intercellular spaces.These findings support the notion that in addition to its association to pathogenic processes exogenously imposed by afflicting agents, P1(p14) is involved in naturally-induced degenerative processes of cells.  相似文献   

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Hereditary non-syndromic sensorineural hearing loss (NSSHL) is a genetically highly heterogeneous group of disorders. Autosomal dominant forms account for up to 20% of cases. To date, 39 loci have been identified by linkage analysis of affected families that segregate NSSHL forms in the autosomal dominant mode (DFNA). Investigation of a large Spanish pedigree with autosomal dominant inheritance of bilateral and progressive NSSHL of postlingual onset excluded linkage to known DFNA loci and, in a subsequent genome-wide scan, the disorder locus was mapped to 3q28-29. A maximum two-point LOD score of 4.36 at theta=0 was obtained for marker D3S1601. Haplotype analysis placed the novel locus, DFNA44, within a 3-cM genetic interval defined by markers D3S1314 and D3S2418. Heteroduplex analysis and DNA sequencing of coding regions and exon/intron boundaries of two genes (CLDN16 and FGF12) in this interval did not reveal disease-causing mutations.  相似文献   

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Summary The chromosome which carries the mutationsexcombless (In(1)sx) affects males and females ofD. melanogaster. In the male foreleg basitarsi the number of sexcomb teeth is dramatically reduced from 10 to 0.7 and the number of transverse rows of bristles is increased from 6 to 8. Females homozygous forIn(1)sx show a normal bristle pattern in the foreleg basitarsus. The genital disc derivatives of both male and femaleIn(1)sx flies are strongly affected. While the external genitalia show a duplicated or a reduced bristle pattern, the internal genitalia are mostly absent. However, the sexually dimorphic tergites and sternites of the abdomen remain unaffected. The male-specific effect on the basitarsus and the general effects on the genital disc derivatives are proposed to represent two different phenotypic effects ofIn(1)sx which may derive from mutations at different gene loci in the inverted chromosome.  相似文献   

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The zoonotic disease tularemia is caused by the bacterium Francisella tularensis. This pathogen is considered as a category A select agent with potential to be misused in bioterrorism. Molecular typing based on DNA-sequence like canSNP-typing or MLVA has become the accepted standard for this organism. Due to the organism’s highly clonal nature, the current typing methods have reached their limit of discrimination for classifying closely related subpopulations within the subspecies F. tularensis ssp. holarctica. We introduce a new gene-by-gene approach, MLST+, based on whole genome data of 15 sequenced F. tularensis ssp. holarctica strains and apply this approach to investigate an epidemic of lethal tularemia among non-human primates in two animal facilities in Germany. Due to the high resolution of MLST+ we are able to demonstrate that three independent clones of this highly infectious pathogen were responsible for these spatially and temporally restricted outbreaks.  相似文献   

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The loss of the L-chromosomes from the germ line of a newly-collected strain of Sciara impatiens was used as a genetic marker to test whether the supernumeraries in this genus obey the rule of origin which governs the behavior of the regular homologues at first meiotic anaphase in the male. Reciprocal crosses between a normal strain which possessed L's and the no-L line yielded F1 males whose germ cells contained L-chromosomes of paternal or of maternal origin. Cytological study of the gonads of these males showed that in all instances, irrespective of their origin, the L-chromosomes were conserved. To demonstrate that the L's thus conserved are not lost subsequently during spermiogenesis, the F1 males derived from normal fathers were bred to females from the no-L line; the gonads of the test-cross progeny showed that these individuals had inherited L-chromosomes. The failure of the paternal L's to obey the rule of origin during spermatogenesis indicates that the supernumeraries in this genus are not subject to the reversible imprinting which the regular complement undergoes. And the genetic effects of exclusively paternal or maternal L-chromosomes on germ cell development and maturation are indistinguishable. Concomitant with the loss of L's from the germ line, the newly-collected strain of S. impatiens underwent an abrupt alteration from unisexual families to variable sex ratios. These ratios are discussed in relation to the problem of sex determination in S. ocellaris, a species which sustained L-chromosome loss during the course of evolution. Discussed also are some new unpublished data which reveal, unexpectedly, a genetic affinity between ocellaris and impatiens. The no-L line of impatiens, which has been kept in laboratory culture for approximately four years, provides a unique opportunity to examine the conditions under which the supernumeraries are retained or lost and also to determine more precisely the nature of their genetic effects.It is a pleasure to acknowledge support by the National Science FoundationIt is a pleasure to acknowledge support by the National Science Foundation  相似文献   

7.
Tuberculosis (TB) remains a major health problem worldwide. Understanding the interactions between the surface components of Mycobacterium tuberculosis (Mtb), the main causative agent of TB, with host immune response will be critical for developments of effective treatments and prevention of TB. Chemically defined mimics of the bacterial envelope components serve as important tools for biological studies of the bacterial interactions with mammalian hosts. We report here a rapid synthetic approach utilizing mannosyl tricyclic orthoesters as monomers for regio- and stereo-controlled polymerizations to generate α(1–6) mannopyranan—the backbone of lipomannan. The polymerizations generated multiple glycosidic bonds in a single chemical transformation in regio- and stereo-selective manners. TMSOTf is the optimum catalyst to promote the selective and high yielding polymerization when compared with other Lewis acids. In addition, the monomers 3,4-O-benzyl-β-d-mannopyranose 1,2,6-orthobenzoate (1) and 3,4-O-benzyl-β-d-mannopyranose 1,2,6-orthopivalate (2) can be synthesized in multiple-gram scale and in a rapid fashion. Characterizations by GPC and NMR indicate the identity of α(1–6) mannopyranan with DPn (degree of polymerization) = 20.  相似文献   

8.
Greenhouse-grown cut flower roses are often irrigated with moderately saline irrigation water. The salt/ballast ions are either present initially in poor quality raw water or reclaimed municipal water, or accumulated in greenhouse irrigation water that is captured and reused. Such ions can inhibit root absorption of essential nutrients. The objective of this work was to quantify the influence of NaCl concentration on the uptake of nitrate and potassium by roses and develop a predictive model of uptake inhibition based on NaCl, NO3 ?, and K+ concentration. One year-old rose plants (Rosa spp. ‘Kardinal’ on ‘Natal Briar’ rootstock) were moved into growth chambers where nitrogen and potassium depletion were monitored during 6 days. Eight different initial NaCl treatments varying from zero to 65 mol m?3 were used and within these there were two initial NO3 ? and K+ concentrations: high concentration (HC, 7.0 mol m?3 and 2.6 mol m?3 NO3 ? and K+ respectively) or low concentration (LC, 3.5 mol m?3 and 1.3 mol m?3 NO3 ? and K+ respectively). Plant NO3 ? uptake was negatively affected by NaCl concentration. NO3 ? maximum influx (Imax) declined from 5.1 µmol to 2.5 µmol per gram of plant dry weight per hour as NaCl concentration increased from zero to 65 mol m?3. A modified Michaelis–Menten (M–M) equation taking into account inhibition by NaCl provided the best fit for NO3 ? uptake in response to varying NaCl concentration. K+ uptake was unaffected by NaCl concentration. A M–M equation that did not include inhibition was suitable for describing K+ uptake at varying NaCl concentration. The resulting empirical models could assist with decision making, such as: adjustment of NO3 ? fertilization based on NaCl concentration, necessity of water desalinization, or determination of the desired leaching fraction.  相似文献   

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An amperometric biosensor was developed to estimate galactose in human blood serum. Monolayers of poly(3-hexyl thiophene) were placed on glass plates coated with indium tin oxide formed by dispensing a mixed solution of stearic acid in chloroform on to a water sub-phase. Galactose oxidase was mixed with poly(3-hexyl thiophene)/stearic acid in chloroform and dispensed on to the air-water interface of Langmuir-Blodgett trough. These monolayers were transferred on to glass plates which were used as working electrodes with platinum as a reference electrode. The amperometric galactose biosensor thus fabricated had a linear response from 0.05 to 0.5 g galactose l(-1) in blood serum. The normal level in blood is < 0.05 g galactose l(-1) in adults and 0-0.2 g galactose l(-1) in infants. In case of galactosemia, this increases to above 0.2 g galactose l(-1) in infants.  相似文献   

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Photon requirements for O2-evolution in red (λ=680nm) light (Фr) were measured for six C3 species, one C3-like, C3–C4 intermediate species, and three C4 species, including examples of NADP-malic enzyme and PEP-carboxykinase C4 sub-groups. Variation in Фr within the C3 species was small with a mean value of 7.96 ±0.12 mol photon mol−1 O2, whereas the mean value for the C4 species was 12.27± 1.53 mol photon mol−1 O2, with the lowest value, 9.24 ±0.13 mol photon mol−1 O2, for the PEP-carboxykinase C4 species Spartina townsendii. The C3–C4 intermediate species Panicum milioides had a value of 9.05 ±0.29 mol photon mol−1 O2, approximately 1 mol photon mol−1 O2 greater than the C3 species. The possibility that this extra cost is due to PEP-carboxylase-dependent recycling of CO2 is discussed. No correlation was found between Фr and chlorophyll content or leaf absorptance. Based on white (ФW) and red light measurements of the photon requirement, values in red light were approximately 20% higher than white-light estimates. These results are discussed with reference to accepted mechanisms of energy transduction in thylakoid membranes (Z-scheme), expected inefficiencies and losses during light-harvesting and electron transport reactions, and the influence of respiratory processes.  相似文献   

14.
Sendai virus (SeV) is an enveloped virus with a non-segmented negative-strand RNA genome. SeV envelope fusion (F) glycoproteins play crucial roles in the viral life cycle in processes such as viral binding, assembly, and budding. In this study, we developed a viable recombinant SeV designated F-EGFP SeV/ΔF, in which the F protein was replaced by an F protein fused to EGFP at the carboxyl terminus. Living infected cells of the recombinant virus were directly visualized by green fluorescence. The addition of EGFP to the F protein maintained the activities of the F protein in terms of intracellular transport to the plasma membrane via the ER and the Golgi apparatus and fusion activity in the infected cells. These results suggest that this fluorescent SeV is a useful tool for studying the viral binding, assembly, and budding mechanisms of F proteins and the SeV life cycle in living infected cells.  相似文献   

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Endosymbioses between chemosynthetic bacteria and marine invertebrates are remarkable biological adaptations to life in sulfide-rich environments. In these mutualistic associations, sulfur-oxidizing chemoautotrophic bacteria living directly within host cells both aid in the detoxification of toxic sulfide and fix carbon to support the metabolic needs of the host. Though best described for deep-sea vents and cold seeps, these symbioses are ubiquitous in shallow-water reducing environments. Indeed, considerable insight into sulfur-oxidizing endosymbioses in general comes from detailed studies of shallow-water protobranch clams in the genus Solemya. This review highlights the impressive body of work characterizing bacterial symbiosis in Solemya species, all of which are presumed to harbor endosymbionts. In particular, studies of the coastal Atlantic species Solemya velum and its larger Pacific congener Solemya reidi are the foundation for our understanding of the metabolism and physiology of marine bivalve symbioses, which are now known to occur in five families. Solemya velum, in particular, is an excellent model organism for symbiosis research. This clam can be collected easily from coastal eelgrass beds and maintained in laboratory aquaria for extended periods. In addition, the genome of the S. velum symbiont is currently being sequenced. The integration of genomic data with additional experimental analyses will help reveal the molecular basis of the symbiont–host interaction in Solemya, thereby complementing the wide array of research programs aimed at better understanding the diverse relationships between bacterial and eukaryotic cells.  相似文献   

16.
In order to clarify evolutionary patterns and processes of intraspecific diversification ofPedicularis chamissonis Steven, we analyzed intraspecific variation of the nucleotide sequences of non-coding regions of chloroplast DNA: the intergenic spacers betweentrnT (UGU) andtrnL (UAA) 5′exon,trnL (UAA) 3′exon andtrnF (GAA), andatpB andrbcL. In 24 populations ofP. chamissonis, 33 nucleotide substitutions and 12 insertions/deletions were inferred, and their genetic distances ranged from 0.001 to 0.014. Seventeen distinct cpDNA haplotypes could be recognized and each haplotype was found to be geographically structured. Two major clades (the Northern and Southern clades) were revealed in phylogenetic analyses of cpDNA haplotypes. The haplotypes of the Northern clade had a wider distribution area in the populations of Mts. lide of central Honshu in Japan, northward to Unalaska Island in the Aleutians. Relationships among most haplotypes were unresolved polytomies. On the other hand, the haplotypes of the Southern clade occurred from the populations of Mt. Gassan southwards to Mt. Arakawa of central Honshu. Within this clade, three subclades were clearly recognized. From these results, we concluded that the haplotypes of the Northern and Southern clades inP. chamissonis might have traveled down to Japanese Archipelago from the north in not a single glacial period.  相似文献   

17.
Bioprocess and Biosystems Engineering - Functional porous hollow microspheres with superparamagnetism, Fe3O4/P(GMA–DVB–St) microspheres, were prepared via a dispersion polymerization...  相似文献   

18.
Summary Reduction of HAuCl4 by NaSCN or KSCN produces colloidal gold particles of 2.6 nm in diameter and homogeneous in size (coefficient of variation 15%). The AuSCN sol forms protein-gold complexes. The amount of protein required to form an AuSCN-protein complex is best determined in the electron microscope, where serial dilutions of protein with gold sol are inspected for the presence of aggregates.By immuno-electron microscopy SCN-gold complexed to protein A is active and visible as is shown by revealing -amylase in rat pancreatic acinar cells.  相似文献   

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