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1.
Barthet VJ 《Phytochemistry》2008,69(2):411-417
cis-Vaccenic acid or cis-11-octadecenoic acid, a C18:1 (n-7) isomer of oleic acid (C18:1 (n-9)) has been found in several oilseeds. It is synthesized from palmitic acid (C16:0) via production of C16:1 (n-7) by a Delta9 desaturase and elongation by an elongase giving C18:1 (n-7). In this study, the fatty acid composition of 12 Brassica species was analyzed by GC-FID and confirmed by GC-MS. All species contained C18:1 (n-7), C20:1 (n-7) and C22:1 (n-7) fatty acid isomers, suggesting that C18:1 (n-7) was elongated. The levels of these fatty acids varied according to the species. C18:1(n-7)) represented from 0.4% to 3.3% of the total relative fatty acid contents of the seeds. The contents of C20:1(n-7) and C22:1(n-7) levels were lower than C18:1(n-7) contents; the relative fatty acid composition varied from 0.02% to 1.3% and from below the limit of detection to 1.3% for C20:1 (n-7) and C22:1 (n-7), respectively. The ratios of (n-7)/(n-9) ranged from 2.8% to 16.7%, 0.6% to 29.5% and 0% to 2.6% for C18:1, C20:1 and C22:2, respectively. Using statistical similarities or differences of the C18:1 (n-7)/(n-9) ratios for chemotaxonomy, the surveyed species could be arranged into three groups. The first group would include Brassica napus, B. rapa, and B. tournefortii with Eruca sativa branching only related to B. napus. The second group would include B. tournefortii, Raphanus sativus and Sinapis alba. The last group would include B. juncea, B. carinata and B. nigra with no similarity/relationship between them and between the other species. Results suggested that the level of C20:1 (n-7) influenced the levels of all monounsaturated fatty acids with chain length higher than 20 carbons. On the other hand, palmitoleic acid (C16:1) levels, C16:1 being the parent of all (n-7) fatty acids, had no statistically significant correlation with the content of any of the fatty acids of the (n-7) or (n-9) family.  相似文献   

2.
The early middle Miocene biota from the Shanwang locality in eastern China is one of the most diverse and well preserved in the world. This overall richness contrasts with its low diversity of anuran amphibians. The most abundant anurans are representatives of the family Ranidae, which remains the dominant group in the extant anuran fauna of China. Besides Rana basaltica Young, some other ranids can be recognised at the locality, and are clearly distinguishable from R. basaltica based on their larger size and different proportions. Ranids are also represented by a developmental series of tadpoles, ranging from approximately Nieuwkoop-Faber (NF) stage 43 to a metamorphosing tadpole of NF stage 57. This is the first known developmental series of fossil non-pipoid Anura outside the Pelobatidae. In addition to the ranids, Bufo shandongensis nov. sp. (replacement name for B. linquensis), represented by one of the earliest known articulated bufonid skeletons, is described and illustrated. Another large toad, Macropelobates linquensis (Yang) nov. comb., is re-described; it can be assigned to the Pelobatoidea, with a possible relationship to the Scaphiopodidae, and can be considered, based on the presence of a large spade, a tibiofibula shorter than the femur, and a short astragalus and calcaneus, to be the earliest known anuran burrower.  相似文献   

3.
The epizootiology of Amblyospora camposi was studied in a natural population of Culex renatoi, a bromeliad-inhabiting mosquito, and its intermediate host, Paracyclops fimbriatus fimbriatus, over a 2-year period. Twenty Eryngium cabrerae plants were sampled monthly from January 2003 to January 2005 and the prevalence of A. camposi in P.f. fimbriatus and Cx. renatoi populations was determined. The monthly prevalence rates of meiospore infections in Cx. renatoi larvae never exceeded 5.5% and was detected in 50% of the monthly samples. Meiospores were available in plants over the course of the study at a mean concentration of 2 x 10(4) meiospores/ml. Within each plant the parasite was maintained by horizontal transmission. P.f. fimbriatus with vegetative stages and mature spores were found regularly in bromeliads suggesting efficient meiospore infectivity to field copepod populations. The mean concentration of spores from copepods found in plants was 8 x 10(2) spores/ml. Infections in copepods were detected in 54% of the monthly samples with a prevalence rate ranging from 0.55 to 17.4% and an overall average of 5.1%. Vegetative stages in fourth instar mosquito larvae (probably derived from the horizontal pathway via spores formed in copepods) were detected in 12.5% of the monthly samples with an overall prevalence rate of 1.1%. Infections in female and male adults were detected in 20.8% of the monthly samples with an overall average of 4.1% and 6.8%, respectively.  相似文献   

4.
The fragmentary remains of a juvenile rhabdodontid ornithopod from the Coal-bearing Complex of the Gosau Group (Lower Campanian, Grünbach syncline) at Muthmannsdorf near Wiener Neustadt, Lower Austria are revised. The material, probably belonging to a single individual, includes a right dentary (lectotype of Iguanodon suessi Bunzel, 1871, designated herein), teeth, a fragmentary parietal, fragments of scapula, ?radius, femur, tibia, two vertebrae (lost) and a manual ungual.The lectotype dentary does not provide clear autapomorphies or sufficient diagnostic features to determine its position within the Rhabdodontidae at generic level. By this “Iguanodon suessi” Bunzel, 1871 and the genus “Mochlodon” Seeley, 1881, to which it was latter referred as type species, cannot be characterized sufficiently by differential diagnosis and these are best considered nomina dubia. Based upon combined character comparisons (mainly postcranial features) the Muthmannsdorf ornithopod is referred herein to Zalmoxes Weishampel, Jianu, Csiki and Norman, 2003, a genus so far known from the late Maastrichtian of Romania. It probably but not evidently represents a yet unnamed species, most closely related to Zalmoxes shqiperorum Weishampel, Jianu, Csiki and Norman, 2003. At the present state of knowledge the Austrian material is not further diagnostic at the species level and kept in open nomenclature as Zalmoxes sp.  相似文献   

5.
The flagellate Crithidia bombi and the neogregarine Apicystis bombi have been found in individuals of Bombus terrestris, a Palaearctic species of bumble bee commercially reared and shipped worldwide for pollination services. B. terrestris has recently entered into the northwestern Patagonia region of Argentina from Chile, where it was introduced in 1998. Prevalence was 21.6% for C. bombi and 3.6% for A. bombi (n = 111). The pathogens were not detected in 441 bumble bees belonging to five of the eight known Argentine native species (Bombus atratus, Bombus morio, Bombus bellicosus, Bombus opifex, Bombus tucumanus) collected elsewhere in the country. Although the absence of natural occurrence of C. bombi and A. bombi in Argentine native bumble bees cannot be ascertained at present due to the limited surveys performed, it is important to report their detection in invasive B. terrestris. The invasion event is relatively recent and the accompanying pathogens are not species specific within the genus Bombus.  相似文献   

6.
Simultaneous use of parasitoids and entomopathogenic nematodes for codling moth (CM) control could produce an antagonistic interaction between the two groups resulting in death of the parasitoid larvae. Two ectoparasitic ichneumonid species, Mastrus ridibundus and Liotryphon caudatus, imported for classical biological control of cocooned CM larvae were studied regarding their interactions with Steinernema carpocapsae. Exposure of M. ridibundus and L. caudatus developing larvae to infective juveniles (IJs) of S. carpocapsae (10 IJs/cm2; approximately LC(80-90) for CM larvae) within CM cocoons resulted in 70.7 and 85.2% mortality, respectively. However, diapausing full grown parasitoid larvae were almost completely protected from nematode penetration within their own tightly woven cocoons. M. ridibundus and L. caudatus females were able to detect and avoid ovipositing on nematode-infected cocooned CM moth larvae as early as 12h after treatment of the host with IJs. When given the choice between cardboard substrates containing untreated cocooned CM larvae and those treated with an approximate LC95 of S. carpocapsae IJs (25 IJs/cm2) 12, 24, or 48h earlier, ovipositing parasitoids demonstrated a significant preference for untreated larvae. The ability of these parasitoids to avoid nematode-treated larvae and to seek out and kill cocooned CM larvae that survive nematode treatments enhances the complementarity of entomopathogenic nematodes and M. ridibundus and L. caudatus.  相似文献   

7.
An increase in clinical cases of Candidiosis globally as well as fungal resistance to drugs prompted the search for novel anti-Candida albicans agents from plant sources. Leaf extracts of Markhamia obtusifolia were screened for activity against C. albicans in vitro. An acetone extract obtained following serial exhaustive extraction contained mainly the active components with at least four active zones on the bioautogram. Bioassay guided fractionation of this extract led to the isolation of three compounds which inhibited the growth of three C. albicans strains. Based on spectroscopy studies (NMR and MS), the compounds were identified as 3β-hydroxyurs-12-en-28-oic acid, ursolic acid (1) 3β, 19α-dihydroxyurs-12-en-28-oic acid, pomolic acid (2) and 2β, 3β, 19α -trihydroxy-urs-12-en-28-oic acid, 2-epi-tormentic acid (3). The most active compound was 3β, 19α-dihydroxy-12-ursen-28-oic acid (2) with a minimum inhibitory concentration (MIC) value of 12.5 µg/mL for C. albicans isolated from dog and 25.0 µg/mL for C. albicans from cat and ATCC 90028 at 24 h following incubation. However, at 48 h of incubation MICs were > 400 µg/mL for all the three compounds isolated. This study indicated that M. obtusifolia could be a potential source of active principles against C. albicans.  相似文献   

8.
Light microscopic observations were made on the hemocytes of three gastropod species namely Trachea vittata, Indoplanorbis exustus and Pila globosa. It revealed two basic types of hemocytes. They are agranulocytes and granulocytes. Agranulocytes are hyalinocytes which are round, unspread hemocytes and have a large nucleo-cytoplasmic ratio. Granulocytes are spreading hemocytes, forming numerous pseudopodia. For the purpose of differential counting, we present a categorization of the granulocytes into three sub-categories based on cell dimensions, nucleo-cytoplasmic ratio, distribution of granules in the cytoplasm and position of the nucleus. The smaller granulocytes are younger cells, and are termed Granulocytes I (Progranulocytes). The larger ones are fully developed cells that have been differentiated into Granulocyte II (basophilic) and Granulocyte III (eosinophilic).  相似文献   

9.
10.
Tubulinosema kingi is a pathogen of Drosophila spp. that was originally described 40 years ago. Although Drosophila melanogaster is widely used as a model organism for biological research, only limited data about microsporidia infecting Drosophila have been published so far and very little is known about the ultrastructure of T. kingi. In this study, we present the results of ultrastructural and molecular examinations of T. kingi. The whole life cycle took place in direct contact with the host cell cytoplasm and all examined life cycle stages contained a diplokaryon. Very few membrane elements were present in early merogonial stages, but their number and order of arrangement increased as the life cycle proceeded. The cell membrane of meronts had a surface coat of tubular elements that encircled the cell. Later, numerous electron-dense strands without any ornamentation accumulated on the plasma membrane, indicating that cells had entered sporogony. The cell membrane of sporonts was covered by electron-dense material. The polar filament in the spores was slightly anisofilar with the last three or four coils being smaller in diameter. The polar filament has 10 to 14 coils which were arranged predominantly in a single row, but in many spores, one winding of the coiled polar filament was located inside the outer coils. In some spores, the polar filament was irregularly arranged in two or even three rows. Molecular analysis showed that all Tubulinosema spp. are closely related and form a clade of their own that is distinct from the Nosema/Vairimorpha clade. All these ultrastructural and molecular features are in concordance with the family Tubulinosematidae and the genus Tubulinosema which reinforces the recent reclassification of this microsporidium.  相似文献   

11.
We investigated differential susceptibility of lady beetles to entomopathogenic nematodes, for two reasons: (1) to estimate potential nontarget effects on natural lady beetle populations, (2) to compare the susceptibility of exotic versus native lady beetle species. We hypothesize that successful establishment of some exotically introduced arthropods may be due, in part, to a lower susceptibility relative to competing native species. In laboratory studies, we compared the pathogenicity, virulence, and reproductive capacity of Heterorhabditis bacteriophora and Steinernema carpocapsae among two native (Coleomegilla maculata and Olla v-nigrum) and two successfully established exotic (Harmonia axyridis and Coccinella septempunctata) lady beetles, and a known susceptible lepidopteran host, Agrotis ipsilon. After 1 and 2 days of exposure to either nematode species, mortality of A. ipsilon was higher than in all lady beetles. Thus, we predict that nematode field applications would have significantly less impact on lady beetle populations than on a susceptible target pest. Additionally, the impact of soil-applied nematodes may be lower on lady beetles than on soil-dwelling hosts because the former spends relatively less time on the soil. Exotic lady beetles were less susceptible to nematode infection than native species. Reproductive capacity data also indicated lower host suitability in H. axyridis, but not in C. septempunctata. Overall, the hypothesis that low susceptibility to pathogens in certain exotic lady beetles may have contributed to competitive establishment was supported (especially for H. axyridis). Additional studies incorporating different hosts and pathogens from various geographic locations will be required to further address the hypothesis.  相似文献   

12.
Larvae of Pseudaletia unipuncta are moderately susceptible to infections caused by entomopathogenic nematodes, being a desirable host to study pathogenic processes caused by Heterorhabditis bacteriophora, Steinernema carpocapsae, and Steinernema glaseri and their associated bacteria. The ability of the infective stage of these nematodes to invade hosts is quite different. S. carpocapsae invades the highest number of insects and presents the highest penetration rate, followed by H. bacteriophora. Regression analysis between the number of insects parasitized and the number of IJs counted per insect, over time, showed a high correlation for S. carpocapsae whereas for H. bacteriophora it was low. Dose-response was most evident at a concentration below 100 IJs per insect on H. bacteriophora, whereas on S. carpocapsae it was found for doses ranging from 100 to 2,000 IJs. Student's t test analysis of dose-response showed parallel, yet unequal, slopes for both strains of H. bacteriophora, whereas distinct regressions were obtained for S. carpocapsae and S. glaseri, thus, evidencing each species develop a distinct pathogenic process. Insects injected with Photorhabdus luminescens died within 50 h after injection, whereas those treated with X. nematophila died much later. Moreover, the mortality in insects exposed to H. bacteriophora complex and injected with P. luminescens was close, but insects injected with bacteria died faster. Insect mortality in treatments with complexes S. carpocapsae and S. glaseri was significantly higher than that which was observed in insects injected with symbiotic bacteria.  相似文献   

13.
14.
Achatina (Lissachatina) fulica was introduced in Brazil in the 1980s for commercial purposes (“escargot” farming) and nowadays, mainly by human activity, it is widespread in at least 23 out of 26 Brazilian states and Brasília, including the Amazonian region and natural reserves, where besides a general nuisance for people it is a pest and also a public health concern, since it is one of the natural intermediate host of Angiostrongylus cantonensis, ethiological agent of the meningoencephalitis in Asia. As Brazil is experiencing the explosive phase of the invasion, the Laboratório de Malacologia do Instituto Oswaldo Cruz/Fiocruz has been receiving samples of these molluscs for identification and search for Angiostrongylus cantonensis and Angiostrongylus costaricensis larvae. While examining samples of A. fulica different nematode larvae were obtained, including Aelurostrongylus, whose different species are parasites of felids, dogs, primates, and badger. Morphological and morphometric analyses presented herein indicated the species Aelurostrongylus abstrusus, as well as the occurrence of other nematode larvae (Strongyluris-like) found in the interior of the pallial cavity of A. fulica. This is the first report in Brazil of the development of A. abstrusus infective larvae in A. fulica evidencing the veterinary importance of this mollusc in the transmission of A. abstrusus to domestic cats. Since the spread of A. fulica is pointed out in the literature as one of the main causative spread of the meningoencephalitis caused by A. cantonensis the authors emphasize the need of sanitary vigilance of snails and rats from vulnerable areas for A. cantonensis introduction as the port side areas.  相似文献   

15.
Chlamydial symbionts in the enigmatic Xenoturbella (Deuterostomia)   总被引:1,自引:0,他引:1  
Ultrastructural observations of the gastrodermal cells in the enigmatic Xenoturbella revealed numerous chlamydiae. They are related to "Candidatus Fritschea" and Simkania (Simkaniaceae) based on 16S and 23S rRNA. Their 23S rRNA gene contains an intron encoding a putative homing endonuclease. The chlamydiae were pleomorphic and formed intravacuolar colonies. They have flattened disk-shaped elementary bodies, either oval or bow tie-shaped in cross-section, and reticulate bodies that are spherical, polygonal or irregularly shaped. All stages have five-layered cell wall with rippled appearance. Bacteria were not observed in the nuclei. The association between the chlamydiae and Xenoturbella is characterized by absence of cytopathological effects; limited host cell response against the chlamydiae; the confinement of the chlamydiae to inclusions in some part of the host cell; and complete and uniform infection of all examined hosts.  相似文献   

16.
Entomophthora leyteensis Villacarlos & Keller sp. nov., a species of Entomophthorales infecting the whitefly Tetraleurodes acaciae on Gliricidia sepium in the Philippines is described. Disease prevalence monitored weekly for 8 weeks indicated that the fungus could cause 8-31% infection within the whitefly population. Epizootics due to this fungus occurred in Inopacan, Leyte. Sampling live whitefly adults and dissecting them on glass slides for microscopic examination of fungal structures was found to give a better measure of prevalence than actual counts of infected insect cadavers. E. leyteensis is an important mortality factor for T. acaciae. Some speculations on the origin of the fungus are discussed here.  相似文献   

17.
Fishes of the family Antennariidae (order Lophiiformes) are primarily shallow-water benthic forms found in nearly all tropical and subtropical oceans and seas of the world, with some taxa extending into temperate waters. Despite an earlier attempt based on morphology, no previous hypothesis of intergeneric relationships of the Antennariidae exists. To resolve phylogenetic relationships within the Antennariidae, and to test the validity of species groups within Antennarius, DNA sequences from the mitochondrial 16S and cytochrome oxidase c subunit 1 (COI) genes, and nuclear recombination activating gene 2 (RAG2), for 25 described and four undescribed antennariid species, representing 10 of 12 known genera and one undescribed genus, were unambiguously aligned and analyzed using Bayesian and maximum likelihood methods. The markers were partitioned and analyzed for substitution saturation and only the third codon position of COI (COI-3) was found to have reached saturation. However, analysis of both datasets, one with the saturated data and one without, differed only slightly. All molecular analyses recovered two major clades, one comprised of Fowlerichthys, Antennarius, Histrio, and Antennatus; and another containing Rhycherus, Antennariidae gen. et sp. nov., Kuiterichthys, Phyllophryne, Echinophryne, Tathicarpus, Lophiocharon, and Histiophryne. Evidence is presented to illustrate a correlation between phylogeny, geographic distribution, and reproductive life history. The results of these analyses provide the first hypothesis of evolutionary relationships within the Antennariidae.  相似文献   

18.
In a chemosystematic investigation of Digitalideae (Plantaginaceae), the water-soluble part of extracts of two species of Digitalis, two species of Isoplexis, as well as Erinus alpinus and Lafuentea rotundifolia were studied with regard to their content of main carbohydrates, iridoids and caffeoyl phenylethanoid glycosides (CPGs). Digitalis and Isoplexis contained sorbitol, cornoside and a number of other phenylethanoid glycosides including the new tyrosol beta-D-mannopyranoside, sceptroside but were found to lack iridoid glucosides. Erinus contained mainly glucose, the new 8,9-double bond iridoid, erinoside, and a number of known iridoid glucosides including two esters of 6-rhamnopyranosylcatalpol, as well as the CPG poliumoside. Finally, Lafuentea was characterized by the presence of glucose, aucubin and cryptamygin B but apparently lacked CPGs. The chemosystematic significance of the isolated compounds is discussed.  相似文献   

19.
An in vitro and in vivo study of some copper chelating anti-inflammatory agents for alleviation of inflammation associated with rheumatoid arthritis (RA) has been conducted. Two copper chelating agents, N(1)-(2-aminoethyl)-N(2)-(pyridin-2-ylmethyl)ethane-1,2-diamine ([555-N]) and N-(2-(2-aminoethylamino)ethyl)picolinamide ([H(555)-N]) have been synthesized as their hydrochloride salt; their protonation constants and formation constants with Cu(II), Zn(II) and Ca(II) determined by glass electrode potentiometry at 298K and an ionic strength of 0.15M. Cu(II) formed stable complexes at physiological pH while the in vivo competitors, Zn(II) and Ca(II) formed weak complexes with both chelating agents. Both [555-N] and [H(555)-N] showed better selectivity for Cu(II) than for Zn(II) and Ca(II). Electronic spectra for species formed at physiological pH suggest a square planar geometry. Speciation calculations using a blood plasma model predicted that these copper chelating agents are able to mobilize Cu(II) in vivo, while bio-distribution studies of their (64)Cu(II)-labelled complexes at physiological pH showed tissue accumulation and retention indicating an encouraging biological half life.  相似文献   

20.
Previous research established different interactions of the insect pathogen, Xenorhabdus nematophila and nonpathogen, Bacillus subtilis, with antimicrobial hemocytes and humoral factors of larval Malacosoma disstria [Giannoulis, P., Brooks, C.L., Dunphy, G.B., Mandato, C.A., Niven, D.F., Zakarian, R.J., 2007. Interaction of the bacteria Xenorhabdus nematophila (Enterobacteriaceae) and Bacillus subtilis (Bacillaceae) with the hemocytes of larval Malacosoma disstria (Insecta: Lepidoptera: Lasicocampidae). J. Invertebr. Pathol. 94, 20-30]. The antimicrobial systems were inhibited by X. nematophila and stimulated by B. subtilis. The bacterial surface antigens participating in these reactions were unknown. Thus, herein the effects of lipopolysaccharide (endotoxin) from X. nematophila and lipoteichoic acid from B. subtilis on the larval M. disstria immune factors, the hemocytes and phenoloxidase, were determined. Endotoxin elevated the level of damaged hemocytes limiting the removal of X. nematophila from the hemolymph and enhancing the rapid release of bacteria trapped by nodulation. Similar effects were observed with the lipid A moiety of the endotoxin. The effects of lipopolysaccharide and lipid A on the hemocyte activities were abrogated by polymyxin B (an antibiotic that binds to lipid A) confirming lipopolysaccharide as the hemocytotoxin by virtue of the lipid A moiety. Lipoteichoic acid elicited nodulation and enhanced phenoloxidase activation and/or activity. Although lipoidal endotoxin and lipid A inhibited phenoloxidase activation they enhanced the activity of the enzyme. Apolipophorin-III precluded the effects of lipopolysaccharide, lipid A, and lipoteichoic acid on the hemocytes and prophenoloxidase until the antigens exceeded a critical threshold.  相似文献   

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